REPAIR GUIDE - PCE|TurboDuo/R/RX: CD Laser Swap & Adjustment Guide

[thesteve]

as long as it spin the scope is useful
from left to right
first 2 adjust for max signal
next pot turn CW till the drive stops, then CCW till it starts again
far right about center
edge of board turn CCW till noise starts and CW till it stops

[danyetman]

I don't mean to be critical, but could  you repeat those instructions using the actual VR10(x) numbers, please?  It's a little hard to figure out your meaning.

[thesteve]

Pots left to right
102 101 104 105
Edge 103

[danyetman]

Nope.  No matter what I do, I can't get it reading CDs again.  Even replaced the HOP-M3 laser with a brand new one.  The most I can get it to do is run silently and have it show the 'please wait' text for some minutes before it says 'Data load error'.

I'm washing my hands of this one, and I could really use someone who is experienced and capable to get it back into working order.  I am beyond frustrated - I am actually quite livid at this.

[schweaty]

Nope.  No matter what I do, I can't get it reading CDs again.  Even replaced the HOP-M3 laser with a brand new one.  The most I can get it to do is run silently and have it show the 'please wait' text for some minutes before it says 'Data load error'.

I'm washing my hands of this one, and I could really use someone who is experienced and capable to get it back into working order.  I am beyond frustrated - I am actually quite livid at this.

i understand... i was in the same boat as you and ended up sending it to thesteve.  he ended up re-flowing the solder on the cd controller chips (something i never would have thought of doing) and it runs great now.  not much help, but an endorsement of thesteve's knowledge and abilities.

[danyetman]

Oi vey.  I just spent three hours starting from scratch and teasing my Duo into functionality.  I suppose there's a pretty big upside to the frustration I've gone through - my Duo is now working faster and with less noise and greater reliability than it was previously. 

So that's a plus, I guess.

Fair warning:  I'm going to vent for a bit about NEC.

Goddamn it, NEC!  Why the blood-soaked Protestant Hell did you use fucking pots on your boards instead of just creating a circuit that did what it was supposed to in the first place?!  Did it really save that much bloody money by using such a back-asswards design?!

Honest-to-God, what the hell were you thinking?!  Did the engineers just collectively say "Fuck reliability" or was your purchasing manager sleeping with the potentiometer sales rep?  I swear before all gods, living or dead, if I EVER find out the name of the guy who gave the go-ahead on such a shitty design, I will hunt him down, stab in the face with a pastry-knife, set him on fire, and piss on his smokey, still-twitching corpse!!!  You hear me, NEC?  FUCK YOU AND ALL YOUR LOUSY-ARSE SHITEFACED ENGINEERS!!!

Rant over.

*sigh*  Just...eugh.  I hope to the Invisible Pink Unicorn that I never have to tweak a Duo back into life again.

[robotype]

today I had my first experience with a duo recap: black japanese duo with new hop-m3 spins but doesn't read so I replace 4 caps like suggested in doujindance video on youtube, it works but only with one game so I rotate ccw the white pot on the lens assembly and reads more games but I still have some problems with music on some games. should I keep rotating the white pot or maybe start messing with the five small pots on the pcb? after reading this discussion I really do not want to touch those (great thread by the way).

[danyetman]

BEFORE YOU TOUCH ANY POTS, USE A THIN PERMANENT MARKER TO MARK EACH POT'S ORIENTATION.

The white pot on the lens assembly itself shouldn't be the go-to pot.  VR103 and VR101 will help with your audio issues; sputtering/dropping music is typically a tracking error thing.  Focus on VR103 first.  Make small, and I do mean small, adjustments, and then do something within the game that will cause it to load a new music track.  If the track seems to play fine, then let the new track play a couple of times in a row to make sure.  If it sputters out or disappears, make another small adjustment.  Lather, rinse, repeat.

If you have a frequency counter or an oscilloscope, attach ground to pin 5 of the P5 connector and touch pin 1 of connector P6 with the lead.  With a CD spinning on the spindle, you should get a reading of 4.3-4.4MHz.  If not, turn VR105 until the reading stays within that range.  Ideally, you want 4.3218MHz, but it's better to have it a little high than it is to have it go under 4.3MHz.

[blueraven]

Rant over.
*sigh*  Just...eugh.  I hope to the Invisible Pink Unicorn that I never have to tweak a Duo back into life again.

Thanks I needed a laugh.

I'll add the part about marking the pots when I update the thread next. Good idea and thanks!

[robotype]

after several hours I could have it working with almost all games, but "kiaidan 00" is the most difficult, music won't work during the game shoild I insist on v101 and v103? I also medded with the white pot on the lens, anyone knows the correct impedance for that one? couldn't measure the frequency yet  but I didn't touch v105 after the recap

[thesteve]

as a rule dont touch VR105
the other pots depend on the laser assembly, thats why they are pots

[danyetman]

Okay, thesteve has pretty much un-idioted me, by which I mean to say that he has taught me very quickly how to use my oscilloscope, which is the greatest tool in the history of ever, and which I consider to be invaluable for anyone attempting to tweak their PCE CD system (whatever it may be) back to life.

Seriously, I can't overestimate how immensely powerful even a cheap scope like mine is.

As far as the white lens pot is concerned, most of them should come with a hard epoxy on the pot, locking it in the factory-determined ideal impedance.  That being said, it's okay to have it 'too strong'.  Sure, it'll shorten the lifespan of the laser itself, but better overpowered than underpowered.

VR105, as I've said before, should be clocked at a fairly precise 4.3MHz frequency.  Because the very nature of a waveform is its undulation, you're going to get readings at both the top and the bottom of the waveform, meaning you'll see the frequency go up and down on your meter.  As a rule of thumb, try to get the frequency of VR105 to go NO LOWER than 4.321MHz, which should mean your peak should be at 4.400MHz, or more likely just under.  Again, better a little strong than a little underpowered.  A decent frequency counter (at least 10MHz) shouldn't cost you more than $15 USD on eBay, and is well worth the investment.

VR103 is your go-to pot if you have scratchy sound or sound that drops out.  On all the Duos I've played with, it seems to have a very, very small window of perfect operation - maybe ten degrees or so, but I'm not sure if this is typical, as my sample group is comprised of the four Duos (all PCE) I have ever seen.

If you're starting from scratch on adjusting the pots, thesteve's directions are perfect:

1)  Pull the RF signal from pin 2 on the P5 connector, and ground it on pin 1 of P5.
2)  Set your scope to 2.00V/Div and 1.000us/Div.  Get your readings while your CD system is trying to load the disc.
3)  While the CD attempts to load, use a plastic or other non-metal small Phillips-head screwdriver to turn VR102.  You're trying to get the greatest amplitude (biggest wave) you can.  Once you've found the spot that makes the wave as large as it can be, move on to VR101 and do the exact same thing.
4)  After you've made the biggest wave you can, set your scope trigger to be at the far left of your screen, and about 3/4 of the way up the waveform you're pulling.  Turn VR104 clockwise until the disc stops spinning.  Once this happens, make the smallest turns you can COUNTER-clockwise and wait a few seconds between each turn to see if the disc starts spinning.  Once it does, move on to VR103.
5)  VR103 is kind of the odd pot out - it's incredibly touchy, and it seems to vary on a per-Duo basis how to set it.  Ideally, you want to turn it until your drive is making no real noise - no squeaks, no whines, no chugs or repetitive clicking noises.  It should run almost silently.  You can find your starting point by turning it counter-clockwise until it starts making a faint whine-like noise.  When this happens, turn it CLOCKWISE by a hair, and I do mean 'just a hair'.  I'm not exaggerating when I say that the VR103 pot has a very small window of operation.  Use a game with a soundtest available right off the bat, like Rondo of Blood.  Playtest the first and last tracks while making minute adjustments.  There should be no crackling or audio dropouts at all.  This can take some time, so be patient, and you'll pull through.

[thesteve]

i set my trigger first
as for the pot on the laser if its too high it causes errors in the focus/tracking circuit
after everything is set adjust the laser pot so your wave is between 0.7Vpp and 1Vpp
it will vary a bit with different media so check it on a few different types of disc if possible

[robotype]

Thank you for the detailed instructions danyetman and thesteve, I fixed my duo! now it seems to read everything and the music plays fine. BUT I noticed while the music is on the sound effects are very very low. is this a common issue? could it be a cap? if I play hucards I hear the audio just fine.

[thesteve]

it could be cap related
there is a mixer circuit that uses cap charge to adjust the mix levels

[robotype]

it could be cap related
there is a mixer circuit that uses cap charge to adjust the mix levels

I want to recap that section, can you point me at which caps could be related to the issue?

[MNKyDeth]

I will go out on limb here and suggest robotype that if you do open up the Duo you should do a full cap replacement on the system. It will only get worse over time if you don't.

Of all the research I have done on the subject from threads on these forums it is in you're best interest to replace all caps on any Duo's if they have not been replaced already. I am not a guru here so second opinions are welcome. I recently did my own Duo and it's like a new machine again.

[robotype]

I opened the duo many times it's very quick I want to try and replace only the caps related to the audio mixing section before the full recap (which I will certanly do when I get the full cap kit)

[BlueBMW]

You're wasting your time only doing a few caps at a time.  There aren't that many total, just do them all, wash the board good (dishwasher does the trick) and enjoy the duo for years to come.

[robotype]

I promise you I will do the full recap but just out of curiosity, if someone knows it, which are the caps related to the audio mix?

[thesteve]

The 2 SMD caps behind the heatsink on the right
They leak so cleaning the area is as important as the parts

[robotype]

The 2 SMD caps behind the heatsink on the right
They leak so cleaning the area is as important as the parts

great! thanks

[robotype]

ok I replaced the two smd behind the heatsink on the right and didn't help, so I replaced the two in front but nothing changed so I recapped the whole thing and now I hear sound effects loud and clear. I think the two caps related to the mixing are the two on the right (near the cd player).

my duo now plays anything perfect (only original games, I don't have CD-Rs)

these are my impedance readings

101 AB  7.3  AC 13.4  BC 19.1
102 AB  8.6  AC  7.8   BC  9.9
103 AB 15.9 AC  2.5   BC 17.8
104 AB 19.4 AC  1.7   BC 20.3
105 AB 0.00 AC  0.36 BC 0.36

I didn't measure the white pot on the lens

[danyetman]

wash the board good (dishwasher does the trick)

*throws hands up in exasperation*  Why on God's green earth does everyone give this horrible piece of advice?  This is probably one of the worst things you could do!  Dishwashing detergents are overwhelming alkaline in nature, which will cause corrosion on metallic surfaces on an epic scale if even the slightest bit remains.

In addition, some of the more aggressive dishwashers are fully capable of pulling SMT components off of boards.

If you want to clean a board properly, use non-alkali degreaser, a soft/medium toothbrush, and do it by hand in the sink.  Then spray the thing down with 90% Isopropyl alcohol and let it air-dry over the course of 3-5 days in low humidity.

[BlueBMW]

I have washed dozens if not hundreds of boards this way and all are still in great operation today.  I work in a circuit board manufacturing plant and guess what we basically use to wash our boards, industrial dishwashers with very similar detergents to what you use at home.  Use very little detergent and you dry the board with an oven.   What I do at home is essentially the same as what I do at work.  And the stuff I build at work goes into satellites, spaceships and weapons.

Scrubbing by hand is great until you miss leaked electrolytic fluid under a chip or in a via that you cant get out with simple scrubbing with a toothbrush.  I know. I used to do it that way... 99% isopropyl and a toothbrush.  Even after that some boards would still have issues.  After a dishwasher wash and oven dry they work perfectly.

Is there some risk with washing them in a dishwasher?  Of course, but I think the risk is far less than leaving leaked electrolytic fluid stuck in some vias or under chips causing a slow death of the traces it touches.

You know who I learned this technique from?  None other than thesteve whom you praise in your signature.

[BlueBMW]

Here's a pic for posterity...

X68000 Compact Mainboard going in for a wash   Computer came out great and works awesome still to this day.

/Crazy_zps67178b9d.jpg

[NecroPhile]

*throws hands up in exasperation*

Throw your hands in the air like you just don't care..... because nobody here cares what you think. 

[PCEngineHell]

wash the board good (dishwasher does the trick)

*throws hands up in exasperation*  Why on God's green earth does everyone give this horrible piece of advice?  This is probably one of the worst things you could do!  Dishwashing detergents are overwhelming alkaline in nature, which will cause corrosion on metallic surfaces on an epic scale if even the slightest bit remains.

In addition, some of the more aggressive dishwashers are fully capable of pulling SMT components off of boards.

If you want to clean a board properly, use non-alkali degreaser, a soft/medium toothbrush, and do it by hand in the sink.  Then spray the thing down with 90% Isopropyl alcohol and let it air-dry over the course of 3-5 days in low humidity.

I think you have no idea how the fuck this has been common practice in the professional electronic repair field for years now for both arcade vendors and computer repair shops. Also, why would you just spray alcohol  all over a pcb and let it sit. What magical process do you think the alcohol does on its own with no human interaction as it dries?

[danyetman]

The alcohol, Mr. Attitude, is used to assist evaporation of the water in order to assure that there's no water left in or on components when it's next powered up.

And for the record, 'common practice' /= 'good practice'.  It is 'common practice' (or was in the 80s and 90s, at least) to blow on NES cartridges when they didn't make a good connection.  However, we know now that this was a placebo fix, and in fact assisted in corrosion of the cartridge pins thanks to the moisture of the blower's mouth. 

Now tell me something - is it 'common practice' to get pissed off and start swearing at someone when you clearly didn't read the entirety of my post?  I quote from my immediately previous post:

If you want to clean a board properly, use non-alkali degreaser, a soft/medium toothbrush, and do it by hand in the sink. Then spray the thing down with 90% Isopropyl alcohol and let it air-dry over the course of 3-5 days in low humidity.

Yet all you focus on is the alcohol, to the exclusion of all else.  In fact, you take that single statement completely out-of-context and treat it as if I prescribed that as the sole remedy, completely missing everything leading up to that.

Next time you want to get pissy about something, do yourself a favor and make sure you know what the hell you're responding to, genius.

[PCEngineHell]

You don't need alcohol to dilute water to assist in drying. All you need is patience, warmth, a small enclosed space you can prop the boards upright in, and a fan. Its called making a drying station. Stop being a lazy fuck trying to act like a know it all pro. You can save the alcohol for actual spot cleaning moron. All you are doing is....lol pouring money down a drain, figuratively speaking.

As for washing boards, its been done in factories and in small repair shops for years now. You have the option to use a cleaning agent or not. Usually just an extended and thorough powerful wash of warm water will do the trick in many cases. You acting horrified at the fact we do this is laughable. It shows how clueless you have been to how this stuff is done on a professional level since jump street.

Scrubbing by hand does not get into nooks and crannies and expose trace damage the way a good wash will. I have done game system, arcade, computer pcbs, and pc power supplies this way for years now with no issue. I have yet to see anything damaged by a wash. No components ever broken off or damaged. What I have done is spot old damage after said wash so I can repair it while avoiding wasting hours of my time trying to pick out bits of crud and corrosive material I missed from a tooth brush scrub.

I'm sorry you don't get that. But hey, just keep your methods to yourself, and shut up when grown folks be talking. Don't like the "attitude"? Fine, leave then. We dont suffer fools around here.


Side note, since we are on the topic of cleaning pcbs, because there is actually dumb fucks out there that do this, for god's sake don't clean them off with shit like WD40. I have seen the damage that kind of shit does. It isn't pretty.

[MotherGunner]

Holy crap, where was I on this thread?

[kisaku]

Hello, before touching something i would like to ask here.
My DUO black is doing "please set disk" when i put a game disk. Audio disks work but sometime audio goes bad. Is it a Caps problem or a calibration lens problem?
Thanks

[BlueBMW]

If the caps havent been done yet then I would start there.  I've seen bad caps affect CD playback for sure.

[kisaku]

If the caps havent been done yet then I would start there.  I've seen bad caps affect CD playback for sure.

I understand. Don't you think pot calibration can resolve the problem? is risky to do before caps?

[BlueBMW]

I would leave the pots alone until you do the caps.  It may be possible to adjust the pots to compensate but some of the caps affect the operation of the laser.  I have had several duos that didnt read discs before a cap job start working perfectly aftewards with no adjustment.

[Vimtoman]

Ok, my problem has been solved.

In my experience DUO-R do not have a hard time reading CD-R. I was having trouble with CD-R and originals.

I say in my experience because between me and my brother we have 3 of these units.

I purchased a known working DUO-R from ebay (from japan) last week and it arrived today. Coincidentally so did my replacement laser unit (also from ebay).

I had borrowed my brother's DUO-R and over the weekend and tested all my discs on it. No errors or issues playing an disc.

I tested my new DUO-R from ebay and found the results to be the same. Perfect.

I did not want to open his unit because it is working properly and it has a region mod switch and I didn't want to disturb anything.

I opened the new DUO-R and measured the pots. The results are as follows:

VR101
AB:10
AC:9
BC:15

VR102
AB:8
AC:10
BC:12

VR103
AB:6
AC:14
BC:15

VR104
AB:7
AC:10
BC:15

VR105
AB:.5
AC:0
BC:.5

I replaced the laser on broken unit and tuned the pots as close as I could get them. The replacement of the laser unit was unbelievably easy. I couldn't believe it literally took 30 seconds.

The results for the pots were as follows:

VR101
AB:9
AC:10
BC:14

VR102
AB:8
AC:8
BC:12

VR103
AB:4.5
AC:14
BC:14

VR104
AB:15
AC:7
BC:10

VR105
AB:.5
AC:0
BC:.5

The result.... I now have 2 perfectly working DUO-R systems. The inside of the unit from ebay is extremely clean and the hu card slot seems to work perfectly as well.

I guess I will sell one now.

I paid $335 with shipping.

A reasonable offer would not be refused. If anyone is looking for a system.

Thanks for the suggestions, and I hope this info is helpful.

Thanks Chester77 this worked for me and my Duo-r is reading every stubborn disk i have.

I would setup using counters and scopes but thought I'd try this first and it reading so quick now.

[deubeul]

Okay, thesteve has pretty much un-idioted me, by which I mean to say that he has taught me very quickly how to use my oscilloscope, which is the greatest tool in the history of ever, and which I consider to be invaluable for anyone attempting to tweak their PCE CD system (whatever it may be) back to life.

Seriously, I can't overestimate how immensely powerful even a cheap scope like mine is.

As far as the white lens pot is concerned, most of them should come with a hard epoxy on the pot, locking it in the factory-determined ideal impedance.  That being said, it's okay to have it 'too strong'.  Sure, it'll shorten the lifespan of the laser itself, but better overpowered than underpowered.

VR105, as I've said before, should be clocked at a fairly precise 4.3MHz frequency.  Because the very nature of a waveform is its undulation, you're going to get readings at both the top and the bottom of the waveform, meaning you'll see the frequency go up and down on your meter.  As a rule of thumb, try to get the frequency of VR105 to go NO LOWER than 4.321MHz, which should mean your peak should be at 4.400MHz, or more likely just under.  Again, better a little strong than a little underpowered.  A decent frequency counter (at least 10MHz) shouldn't cost you more than $15 USD on eBay, and is well worth the investment.

VR103 is your go-to pot if you have scratchy sound or sound that drops out.  On all the Duos I've played with, it seems to have a very, very small window of perfect operation - maybe ten degrees or so, but I'm not sure if this is typical, as my sample group is comprised of the four Duos (all PCE) I have ever seen.

If you're starting from scratch on adjusting the pots, thesteve's directions are perfect:

1)  Pull the RF signal from pin 2 on the P5 connector, and ground it on pin 1 of P5.
2)  Set your scope to 2.00V/Div and 1.000us/Div.  Get your readings while your CD system is trying to load the disc.
3)  While the CD attempts to load, use a plastic or other non-metal small Phillips-head screwdriver to turn VR102.  You're trying to get the greatest amplitude (biggest wave) you can.  Once you've found the spot that makes the wave as large as it can be, move on to VR101 and do the exact same thing.
4)  After you've made the biggest wave you can, set your scope trigger to be at the far left of your screen, and about 3/4 of the way up the waveform you're pulling.  Turn VR104 clockwise until the disc stops spinning.  Once this happens, make the smallest turns you can COUNTER-clockwise and wait a few seconds between each turn to see if the disc starts spinning.  Once it does, move on to VR103.
5)  VR103 is kind of the odd pot out - it's incredibly touchy, and it seems to vary on a per-Duo basis how to set it.  Ideally, you want to turn it until your drive is making no real noise - no squeaks, no whines, no chugs or repetitive clicking noises.  It should run almost silently.  You can find your starting point by turning it counter-clockwise until it starts making a faint whine-like noise.  When this happens, turn it CLOCKWISE by a hair, and I do mean 'just a hair'.  I'm not exaggerating when I say that the VR103 pot has a very small window of operation.  Use a game with a soundtest available right off the bat, like Rondo of Blood.  Playtest the first and last tracks while making minute adjustments.  There should be no crackling or audio dropouts at all.  This can take some time, so be patient, and you'll pull through.

Few questions about scopes / frequency counters:

- would scopes like this would do the job?:

http://www.ebay.fr/itm/Kit-Oscilloscope-DSO138-2-4-TFT-numerique-DIY-Parts-Set-electronique-1Msps-/131538450791?hash=item1ea04d7967:g:CREAAOSw37tWA5z-

- If yes, Do I still need a FC like this for VR105?:

http://www.ebay.fr/itm/KKmoon-Frequence-de-loscillateur-cristal-MHz-50-Counter-testeur-Kit-0WN8-/181825855970?hash=item2a55aa61e2:g:-xYAAOSwpdpVXeAq

-If not, what type/model of scope would be required to set/verify  lasers on Duos/CDromroms ?

[thesteve]

fact is the DSO may or may not, as nobody has tried one yet
you will never need the FC for VR105

[deubeul]

Thanks for answering Thesteve. 

This made me think afrequency counter would be usefull for VR105:

VR105, as I've said before, should be clocked at a fairly precise 4.3MHz frequency.  Because the very nature of a waveform is its undulation, you're going to get readings at both the top and the bottom of the waveform, meaning you'll see the frequency go up and down on your meter.  As a rule of thumb, try to get the frequency of VR105 to go NO LOWER than 4.321MHz, which should mean your peak should be at 4.400MHz, or more likely just under.  Again, better a little strong than a little underpowered.  A decent frequency counter (at least 10MHz) shouldn't cost you more than $15 USD on eBay, and is well worth the investment.

The fact is I already have a DIY scope like the one I linked, but the screen arrived broken. I've been refund, but now I hesitate to buy a new one, especially if it's useless for PcE lasers.

[thesteve]

think of VR105 like the V-Sync knob on the old TV
it sets an oscillator slope, that needs to be reset by the CD data before it reaches its freq setting
if its too low it could pickup harmonics, but set too fast it will cut the data frames short and fail to read the disc

[Phase]

Got a few questions here
I just recently got around to capping my duo,(I decapped it after I got it a few years back but never got around to the recap ) its running good now and I also just fixed the high pitched ringing noise by adjusting pot 102 a quarter turn cc like mentioned here
https://www.pcengine-fx.com/forums/index.php?topic=3586.msg122549#msg122549

Just wondering when should you replace the laser? what are the problems the lasers start to have?

Also about putting the board in the dishwasher, Is it ok to do this with the new caps and all?
And what about dishwasher settings and the hot steam dry is this all ok?
for oven drying what temp do you want and how long.. can I bake at the same time?

I had trouble with a few pads that must have had old capfluid or something in the old solder, ended up hitting them a few times (possible burning the stuff away) before I got some solder on the board but they look a little dirty, is this going to be ok? or should I redo them and try and get rid of the old solder?  (I'm a bit of a novice and have only done minor soldering here and there)

[thesteve]

washer is fine, normal settings (anything loose may come loose so be aware of it)
as far as laser failure it happens several ways
some wont read certain discs, where others just stop reading
some work for awhile and stop, then work again later

[SegaSonic91]

It's been a long time since I took the screws out of my PCE DUO, and I seem to have "misplaced" them.  I always planed on replacing those torx #10 screws, one of which stripped and was a complete bitch to get out, with regular Phillips once the thing was complete.  I tried looking for "#40 1/2" pan" but never found anything that looked right.  So for instance, is http://www.ebay.com.au/itm/Qty-5-Pan-Head-Machine-4-40-UNC-x-1-2-Stainless-SS-304-Screw-Phillip-Bolt-BSW-/231669035899?hash=item35f08cf37b:g:jPoAAOSwMmBV4HC7 correct?  They look far too long to me.

[mickcris]

It's been a long time since I took the screws out of my PCE DUO, and I seem to have "misplaced" them.  I always planed on replacing those torx #10 screws, one of which stripped and was a complete bitch to get out, with regular Phillips once the thing was complete.  I tried looking for "#40 1/2" pan" but never found anything that looked right.  So for instance, is http://www.ebay.com.au/itm/Qty-5-Pan-Head-Machine-4-40-UNC-x-1-2-Stainless-SS-304-Screw-Phillip-Bolt-BSW-/231669035899?hash=item35f08cf37b:g:jPoAAOSwMmBV4HC7 correct?  They look far too long to me.

They probably have a generic picture there.  The screws you need are some type of course thread. I have not ever measured them though but that is definitely the wrong kind of screw and wrong thread.

edit:
i did a rough measurement.  They do look close to a #4 so im guessing its actually an M3 and they are about 12mm long.  This is my best guess as to the size.  not 100% sure this is correct though
http://www.ebay.com/itm/20X-M2-M5-304-Stainless-Round-Head-Phillip-Pan-Head-Flat-Tail-Self-tapping-Screw-/171951921628
black
http://www.ebay.com/itm/100PCS-M3-M4-M5-Philips-Round-Head-Screw-Self-Tapping-Horizontal-Tail-Bolt-Black-/272013654380

can maybe find those locally or a cheaper listing on ebay with less quantity

edit again:
updated the link with ones that have the same flat bottom

[blueraven]

can maybe find those locally or a cheaper listing on ebay with less quantity

Phillips Pan Metal Screws: #4 x 1/2in available in 100 packs at ACE Hardware for just over $12

If you send me an address, Segasonic91 I can send you 5. I always have a box of these lying around.

Good link Mickcris, the only thing that would be in question is the length. 1/2" is appropriate, and 5/8" will work is the bolt is stripped, but I wouldn't go any longer or shorter here. The Duo wont close properly.

[mickcris]

can maybe find those locally or a cheaper listing on ebay with less quantity

Phillips Pan Metal Screws: #4 x 1/2in available in 100 packs at ACE Hardware for just over $12

If you send me an address, Segasonic91 I can send you 5. I always have a box of these lying around.

Good link Mickcris, the only thing that would be in question is the length. 1/2" is appropriate, and 5/8" will work is the bolt is stripped, but I wouldn't go any longer or shorter here. The Duo wont close properly.

I measured again and the OG screw threads are exactly 12 mm long.  They have them in 14mm also if you want some longer ones.  I am assuming, since these systems were made in Japan, the screws are metric.  12mm is 0.472441 inches and 14mm is 0.551181 inches.  Im not sure from his post if the head is stripped or the inside of the hole.  The ones you are using may have that split in the end which makes less threads where the ones i have linked have threads the whole way to the bottom like the originals.  like this one that will not hold as good cause of its end:
http://www.homedepot.com/p/Everbilt-8-x-3-4-in-Zinc-Plated-Self-Drilling-Pan-Head-Phillips-Drive-Sheet-Metal-Screw-100-Piece-per-Pack-801042/204275119

I was only not sure about the M3 size but I think its coorect

[blueraven]

Here is what I'm using:

can maybe find those locally or a cheaper listing on ebay with less quantity

Phillips Pan Metal Screws: #4 x 1/2in available in 100 packs at ACE Hardware for just over $12

If you send me an address, Segasonic91 I can send you 5. I always have a box of these lying around.

Good link Mickcris, the only thing that would be in question is the length. 1/2" is appropriate, and 5/8" will work is the bolt is stripped, but I wouldn't go any longer or shorter here. The Duo wont close properly.

I measured again and the OG screw threads are exactly 12 mm long.  They have them in 14mm also if you want some longer ones.  I am assuming, since these systems were made in Japan, the screws are metric.  12mm is 0.472441 inches and 14mm is 0.551181 inches.  Im not sure from his post if the head is stripped or the inside of the hole.  The ones you are using may have that split in the end which makes less threads where the ones i have linked have threads the whole way to the bottom like the originals. 

I was only not sure about the M3 size but I think its coorect

I assume that you are correct about the metric sizes versus standard, I will say that this was a suitable alternative for the time being, but I was wondering about the pitch of the threads. I have had some cases where repetition of removal/install has broken down the posts and left the system running with 4/5. They do have threads going all the way down though. I could look for the metric equivalent.

[mickcris]

they are self tapping so the the original screw cut the threads. Not sure if the metric and standard thread pitch is the same so using those ones could possibly be damaging the holes if they are not the same.    You need to make sure the screw is going into the originally cut threads or it will strip out the hole.  I use the method that game-tech-us was recommending in one of his videos where you turn the screw ccw till you feel it go back into the hole and then start going cw.

edit:
those ones you have do have that point at the end which is counted in the length.  that part of the screw is not going to be doing anything.  so that is going to make the threads maybe about a mm shorter.

[NightWolve]

Yikes, I never shop at ACE Hardware unless I just need something in the dollar range...

Got ripped off so bad there on so many things compared to what I saw when Menards and Home Depot came around... They're the absolute worst with the highest prices on everything.

[blueraven]

Yikes, I never shop at ACE Hardware unless I just need something in the dollar range...

Got ripped off so bad there on so many things compared to what I saw when Menards and Home Depot came around... They're the absolute worst with the highest prices on everything.

Yeah they are. The place I went to years ago had a 25% off sale which made them about the same price as Harbor Freight.

...could possibly be damaging the holes if they are not the same.    You need to make sure the screw is going into the originally cut threads or it will strip out the hole.  I use the method that game-tech-us was recommending in one of his videos where you turn the screw ccw till you feel it go back into the hole and then start going cw.

The threads lined up perfectly (or so I thought) when I checked the screws against the Safety bits that came out of the Duo. Most of the systems haven't broken a post due to this issue, rather the brittle nature of the plastic and having been opened up too many times. Also, yes, I do turn them CCW before insall to make sure that they are seated.

...so that is going to make the threads maybe about a mm shorter.

On the bottom end, yes. I hadn't thought of that.