Messages

[Console Repair/Mod Center / Re: LaserActive Help Anyone?]

I nornally measure the voltage on the main board ( the board has a lot of pots to adjust the lens,  eg,  focus gain,  rf level,  etc...  ). In that board,  it has bunch of voltage labels eg,  5v,  -5v,  etc.. and I take the measurement from there.

I saw quite a lot of missing -5v (negative)  due to bad resistor (2.2k)  on the power board.  I never see missing +5 
though.

If you confirmed it is missing +5v, you may refer to cld-a100 service manual to see the path for +5v on the power supply board and hopefully found defect component thru the path.

[Console Repair/Mod Center / Re: LaserActive Help Anyone?]

This issue most likely due to capacitor issue on the interface board inside the laseractive

https://www.pcengine-fx.com/forums/index.php?topic=9267.0

Please refer to 1st update on the FAQ ( both green lights are off after eg, 10 seconds )

I would prefer to replace All the capacitors on the interface board ( the board inside the laseractive which connect to PAC ). However, based on my experience, this is due to the small 16v10uf cap on the interface board.

Once replaced the cap ( well, or all capacitors ) on the interface board, the green lights off issue should be gone.

[Buy/Sell/Trade / PC Engine Game for sale]

deleted

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

OK, service manual wasn't really helpful (at least my paper copy) in this aspect. It has the circuit board pictures and shows component locations etc., but there is no component value list, at least for caps or resistors...

So, I took a picture and added some ellipses on it. Please, see the attachment, this is what I'm trying to explain.

Oh, ic, you found my old post regarding the resistors values ( in page 7 )

yes, I confused the resistors position

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

Long time no message, but I have good news. I got the player working after all few weeks ago. No cold solder joints were found from service (or other) board. I was not able to get a good playback from the laser (picture was black and white + really distorded at the best) so I ended up taking laser from another good to know LA. After moving the laser from unit to another I carefully turned the pots to similar positions as in the donor LA. And voila, LA started playing all discs at once without problems. Also LD picture quality was instantly really nice.

Now I'm working on another unit (actually third...) and made some findings from the power supply. Here is the old list (by choijimmy) from previous posting:

R301 is 2.2k
R302 and R303 are both 220ohm
R304 in my board is a bridge, not resistor

The board I'm working on now has:

R301 = 2.2k
R302 = 2,7k - yes, red-violet-red (btw, this was broken 2,2k -> ~195k from the previous psu I was working on, and the broken resistor is still on my desk, it's red-red-red)
R303 = 220
R304 = 220

Is there a mistake in previous list? BTW, the markings in the PCB on solder side are a bit confusing, it's more clear from component side...

What you mean previous list ? I am a bit confused the different between 1) old list ( by choijimmy )   2) previous list  3) the one you are working on.
Also, what is the issue for the one you are working on ?

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

Some reporting:

It's really apparent by now that when the caps go bad, a lot of things may happen. The LA I'm working on didn't got a power surge (ie. did NOT die suddenly from over voltage, which could be really apparent in such large damages), it just gradually started having problems with disc (CD) playback -> in the end didn't play anymore disc whether CD or LD, just tried to do so...

Found out so far:

Several more or less leaked caps from various boards.

2.2k resistor in power supply transformed itself to something like 195K (causing the -5V line to be something else...)

Audio demodulator toasted (apparently due to -5V failure)

2x burned fuses on service board


What is remarkable is that none of the fuses in power supply went out. So, the supply kept feeding the system even while caps were leaking and voltage levels were incorrect.


After changing caps, 2.2K resistor and two fuses:

Laser led functionality looks correct (moves up/down again)

LD and CD are again detected correctly

Disc spins to apparently good speed (after parts change it didn't spin correctly before I made some tuning to potentiometer sitting on the laser led ribbon cable)


However, laserdisc playback seems to be not working yet. The Play-button led keeps flashing, not constantly lit as it should be in normal situation.


Now waiting for service remote, service LD and part shipment to get the audio chip etc.

As per chat, try to turn the pot on the laser back and forward ( just make sure don't over 2PM position ) to see it helps.
Also, double check the service board, make sure No 3 legs transistors have bad/cold solder joint

[Console Repair/Mod Center / Re: Duo / TurboDuo Low Volume Sound Fix - Ultimate Guide]

Awesome. Really appreciate for the detail pictures

[Console Repair/Mod Center / Re: Laseractive doesn't read Mega LD/CD]

Don't think it is due to track alignment.
If you read his original message carefully.

"now regular CDs and LDs play fine."

The player is OK to play music cd and movie ld.  Just mega cd and mega LD are Not good.

If track alignment for the LD player is bad,  I wonder how can it  play some type disc(movie LD /misic cd)  but unable to play game cd/ld.

[Console Repair/Mod Center / Re: Laseractive doesn't read Mega LD/CD]

Update:
I am able to fix the Sega pac unable to read cd(keep spinning)by replacing the ic17 and ic 18, they are 64k ram for   
Cdrom decoder. (Mb8464)

[Console Repair/Mod Center / Re: NEC LASERACTIVE problem]

LD spins, seems some good sign... Please try to turn the pot marker to 12 o'clock position

I am unable to upload the picture which shows the position. what is your email ?

[Console Repair/Mod Center / Re: NEC LASERACTIVE problem]

The pot is located on the laser lens.  It is a tiny pot on top of the ribbon cable and below the white circle of the lens

[Console Repair/Mod Center / Re: NEC LASERACTIVE problem]

Then 2 things I will do first.

1. Use water to clean the laser lens.
2. If still no luck,  try to adjust the pot on the laser lens just a little bit (clockwise)  to see if it helps

[Console Repair/Mod Center / Re: NEC LASERACTIVE problem]

Is the ld/cd unit ( PCE-LD1 ) ever work since you got it ?

there is a little FAQ/truoubleshooting guide for laseractive, you can have a quick look

https://www.pcengine-fx.com/forums/index.php?topic=9267.0

Thanks

[Console Repair/Mod Center / Re: 265kb static RAM]

Further proof by SNES/SFC  ( using MS62256 CMOS )

Sega CD/Pac-S1:   Psuedo ---replaced by ---->  CMOS   ( good )
PC Engine         :   CMOS   ---replaced by ----> Psuedo   ( bad )
SNES/SFC         :   CMOS   ---replaced by ----> Psuedo ( bad )

So far, the conclusion ( yet ) is  Psuedo can be replaced the CMOS SRAM but Not the other way around.

[Console Repair/Mod Center / 265kb static RAM]

Hi All,

  I have a question about 256kb static RAM using by PC Engine, Sega mega CD, Sega PAC-S10,etc...

I was told the 256kb *Psuedo* static RAM ( eg, HM6*5*256 )  and  *CMOS* static RAM ( eg, HM6*2*256, HSRM20256) are NOT compatible  ( couple RAM re-sellers told me that )

Because of this, I always replace them with exact same type.

However, yesterday, I have replaced  a Psuedo ram ( Sega Pac-S1) - HM65256  with  CMOS ram HM62256 by mistake.

Interesting enough, I found it works !   

Then I starting thinking indeed they are compatible. ( which is same as what console5 said )

In order to prove this, I try to replace a good  PC Engine 256kb CMOS ram ( HSRM20256LM12 )
with Psuedo ram ( eg, HM65256 ) just for testing. However, this time, it failed. ( eg, scrambled  picture )

Here is the test result:

Sega CD/Pac-S1:   Psuedo ---replaced by ---->  CMOS   ( good )
PC Engine         :   CMOS   ---replaced by ----> Psuedo   ( bad )

Seems 256kb CMOS vs Psuedo static RAM are Not 100% compatible and depends on circuit design/machines.

Am I correct ?

[Console Repair/Mod Center / Re: PC Engine / TurboGrafx 16 CDRom ?]

I wonder how-on-earth that was discovered. 

I'm not sure if anyone else has tried the swap, but I only found out because the normal TurboGrafx CD-ROM drives were too expensive but the CDR-35Ds were just cheap enough.

When I got my TurboGrafx it came with the CD booster but no drive or system card and both of those were out of my price range. Almost ten years later I did find a smashed up drive at a flea market but the chips were intact. Since the drives looked so similar I guessed there was only a small change inside and after ordering and disassembling a CDR-35D the boards looked identical and the D78C14GF was suspect since it's a microcontroller with mask rom.

So I swapped the chips and this is how I've been playing CD-ROM games for the past seven years.

Thanks for the info. I confirmed by swapping D78C14GF  does work!

Indeed, I did swap the D78C14GF with my spare IC few days Before your post. I got a little improvement ( eg, at least I got "PC" LED light when pressing the "start" button" ). However, it still Not able to read the CD games. At that momoent, since I am Not sure this is the RIGHT solution or not. Thus, I gave up.

After reading your post, since I know it is RIGHT solution to swap the IC. I found another spare D78C14GF and this time, it works !!!!  I bet the 1st spare D78C14GF  I tried is defective.

Really appreciate your help.

By the way, any idea how to re-program D78C14GF ( if already programmed ) ?  eg, what kind of equiment?
Thanks!

[Console Repair/Mod Center / Re: PC Engine / TurboGrafx 16 CDRom ?]

Got it.  Thanks a lot

[Console Repair/Mod Center / Re: PC Engine / TurboGrafx 16 CDRom ?]

Thanks for the info!

[Console Repair/Mod Center / PC Engine / TurboGrafx 16 CDRom ?]

Hi,

  I recently got a cdrom
( model CDR-35D-01 -- 2nd item in this link   http://www.pc-engine.co.uk/?section=systems  ).
 It looks like PC Engine / TG-16 cdrom but also look like NEC computer cdrom.

  I plugged into PC Engine interface unit and seems *Not* working with it ( eg, when I press start, No "PC" light show up ).  However, I do know the cdrom works fine because I can play music cd when I press "Play" button on top of the cdrom unit.

Any idea what is it for ?

One more question, is TG-16 cdrom  and PC Engine cdrom interchangeable?

Thanks!

[Console Repair/Mod Center / Re: Laseractive doesn't read Mega LD/CD]

The Sega pac can work without saving battery

[Console Repair/Mod Center / Re: Laseractive doesn't read Mega LD/CD]

I do see this problem before. 
- Once is solved by recap the INT assy and works for me.

- Once is due to one of the Big 3 legs transistor have cold/break solder join on the FTSB ASSY board ( the board with a lot of pots eg, focus gain, track gain,etc... )

- once is due to the faulty Sega pac which only work for cart but Not ld/cd even after recap.  I am Unable to fix this issue.

I would suggest to find any other confirmed good pac to test it out first.  The reason is take out those PCB boards from laseractive unit is pretty painful.

[Console Repair/Mod Center / Re: NEC PCE-LD1 LaserActive fault :/]

How about the light of the ld/cd eject buttons?  Are they off  when problem happened?

[Console Repair/Mod Center / Re: Install faster CPU, will it work?]

In theory it should work, no? 10mhz is the max speed that it can run stable, lower speed shouldn't be a problem.

I'm curious about this as a friend had a Killer Instinct Arcade board with a fried CPU, the only replacement that I could find was a faster CPU, he hasn't gone through the repair so I don't know if it indeed works.

The CPU in KI was made for desktop applications so it's ability to scale may surpass that of the 68000. What actually tells the CPU what speed to run at in a Genesis? Is it throttled by anything? A crystal or something? If so, this won't be a problem. If not...

On a Genesis, it's a JO crystal.

There is actually a mod to reduce slowdown where you use a faster crystal. Maybe it's worth a view to see how that is done and what it actually changes.

Thanks a lot.  Have checked that,  seems faster CPU is OK since actual speed is controlled by crystal

[Console Repair/Mod Center / Re: Install faster CPU, will it work?]

In theory it should work, no? 10mhz is the max speed that it can run stable, lower speed shouldn't be a problem.

I'm curious about this as a friend had a Killer Instinct Arcade board with a fried CPU, the only replacement that I could find was a faster CPU, he hasn't gone through the repair so I don't know if it indeed works.

Thanks for the reply. I am also thinking faster CPU should be ok, probably, I just buy one cpu and give a try next time.

[Console Repair/Mod Center / Install faster CPU, will it work?]

I recently have laseractive Sega pac-s1 with broken 68000 8MHz CPU (HD68HC000FS8)   .  Once I swapped with my spare part(doner from another completely dead pac-s1),  it works fine now 

I would like to buy few HD68HC000FS8 for future use.  However,  the only one I can find is HD68HC000FS10 which I assume 10MHz.

Question: can I use 10MHz cpu instead of 8MHz one?  Thanks!

[Console Repair/Mod Center / Re: General CD Unit Question]

So I was looking around at getting this extra Core Grafx I picked up recently into a set-up capable of playing CD games. I like the look of the Super CD-ROM² but it seems like every listing I see for one, something is wrong. No sound, low sound, longer than normal read times, sometimes doesn't read cds etc... So I ask people much more experienced than myself, is this pretty common? Is it just a total piece of garbage or can it be reliable with proper care?

Also I know many will suggest a Duo, but I'd rather not. I already have this Core Grafx so I'd rather just pair it with a CD unit and then I'll be gifting it. I'm not completely opposed to it, but selling the Core Grafx is extra work.

Probably not doing this for a few months yet. When I do though, I might also be looking for some cheaper hueys and cds (racing games mainly) to go with it.

If mods feel this is in the wrong section, let me know. I wasn't fully sure.

All super cdrom I got ( around 7 to 8 ) suffered low sound / unable to read cd.

For low ( not NO ) sounds, all of them can be repaired by changing the capacitors + washing the PCB ( yes, you have to wash the PCB around the power supply section ).

For unable to read cd, mostly due to capacitors as well. For few of them need to replace the laser lens which is very easy to find ( KSS-210A/B )

However, I got one with No sound ( No music cd audio but Hucard is fine ) which never be able to repair even I swap the chips , replace the cap, etc... just unable to fix it and give up.

In my opinion, super cdrom's laser lens is much easier to find ( compare to briefcase cdrom ). However, it suffered sound problem which is pretty annoying.  On the other hand, the briefcase cdrom normally only suffered middle gear issue which is easy to replace.  Well... unless the briefcase cdrom has laser lens issue ( KSS-220A ) which is very hard to find replacement.

If you are good in replacing the capacitors and PCB washing, Super cdrom is worth to try. Otherwise, briefcase cdrom may be better option.

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

As per service manual, its part of its initialization routine. Laser sees CD first but then doesnt see it anymore. timer runs out and ejects tray.

i

Cool.  Good to know this

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

Congrats.  Strange enough by shipping the whole laseracrive main unit will bend the little copper wire. 

I do see a lot of shipping broke the laser itself when just ship the laser assembly itself, once a while,  the copper wire is even broke and disconnected. 

In additional,  I am a bit surprised the tray will be ejected in this case,  I thought the laser will just sit back and keep the tray stay in the main unit.

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

unable to upload how main pcb look like due to  forum upload folder full ??

Basically, it is the pcb with a lot of pot which control the power/tune of the laser

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

More testing .. more results.

- I tested every fuse on the power board.  All good.
- The boot process is as following:

No disc:
- laser rail comes up
- laser moves to track 1 position
- laser detects no disc
- moves back down

With CD:
- laser rail comes up
- laser moves to track 1 position
- laser white eye moves up down and stops
- Tv shows "Compact Disc"
- after a few seconds the disc ejects!

At no point did the CD ever spin!!  On some rare cases (once every 20 tries or so) the disc does spin! But then stops and ejects.  So I can't imagine it's any of the fuses (fuse either blown or not blown)

NOTE: This is the Japanese LA being plugged into USA mains.  But that should not be a problem as it worked this way for YEARS (I think the first thing after the fuse is it runs into a transformer that converts it to DC power).  The only thing that recently changed was it got shipped to me across the country and I have video of it working before shipping.   

So the problem is either bad motor or something else.  I believe the motor gets its power from the main power supply board (red/green wire that plugs into 2 pin molex closest to back of LA). 

I get the same behaviour when that molex is unplugged.  So I put my voltmeter on in.  Always reads 0V.  On the rare case it spun, it read up to 8V, but never steady voltage (a lot of bouncing around). and then down to 0V and tray ejected.

At this point, I'm thinking it's once of the power regulators on the power PCB under that shield.  I traced one of the pins on that connector to a cap, resistor, and then regulator there.

I've made a youTube video showing the problem:  https://youtu.be/ykSUIgLfOKg

Thanks for any suggestions you guys might have.

Do you have laserdisc? if yes, would you try to put in a laserdisc and to see what happen?
I suspect few things

1) belt
2) the motor itself ( when you try to spin the motor by hand, does it spin easily )
3) the main board has loose component ( see attached picture for the board )

Let's try easy one first, put the laserdisc in and to see what happen

[Console Repair/Mod Center / Re: DUO R disc spin but doesn't move]

Yes i think it is the stop switch problem. Is it easy to change?

yes, very easy. two mintues work. PM me you address and I will send you one for free. thanks!

[Console Repair/Mod Center / Re: DUO R disc spin but doesn't move]

I have similar thought as Keith,  sounds like some mechanical problem.  I have some brand new stop switch and send you for free.  I also think(need to double check) I have spare old lens motor (but withOUT the disc holder plate), just motor,  also can send you for free,  let me know if you want to try.

Thanks

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

Please, what are the values of resistors R301, R302, R303 and R304?
They're very light color, I can not identify.

R301 is 2.2k
R302 and R303 are both 220ohm
R304 in my board is a bridge, not resistor

[Console Repair/Mod Center / Re: PC-Engine CD-ROM2 Laser problems?]

For some reason, It Came From the Desert seems to work now with no choppiness. Rondo still is having the same problems.  All I had did since then was clean the lens and mess with tracking.  I'm fairly certain I put the tracking back in the spot it was normally. The version of Rondo was verified and I've tried like 3 other versions.  All seem to hang up in that spot.

If only Rondo ( cdr ) is unable to play well. I wonder if you source of copy have issue.
Do you have original Rondo cd ? Do you have issue when you play original/real/non-cdr  Rondo?

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

congrats!

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

When I turn on the laseractive, I found that the laser lens is bouncing up and down crazy.
I believe the solution to this problem is to "update 3" but I did not understand.
Please, I need help because I'm unable to play cd/ld

I recall you said the fuse blown everytime when you turn on the machine,  now the fuse no longer blown?

In my update 3, what I mean is you should measure if you get -5v from the power supply board or not.  You can find -5v measuring point from the PCB which have a lot of pots. 
If you missed -5v, then most likely the resistor r301 in the power supply board has issue.  This resistor suppose 2.2k,  check  the resistor value by taking out from power supply board.  If the value is far away from 2.2k, replace it

[Console Repair/Mod Center / Re: CDROM2 glitches when warm.]

Yes, those 4.7uf caps failed quite often.

[Console Repair/Mod Center / Re: fix for cdrom broken guide rail plastic thingy]

thanks for the guideline!

[Console Repair/Mod Center / Re: need some advice about repairing a PC Engine Cd Rom2]

Would 50v 4,7uF work well? Belive the original are 16v.


Skickat från min iPad med Tapatalk

50v 4.7uf will work. As long as the replacement cap has same uf,   equal or higher voltage is fine.

[Console Repair/Mod Center / Re: Scratched SCD = Worthless?]

I bought a disc repair machine called "jfj easy pro" and never regret since then. The machine is so easy to use and able to repair a lot of heavily scratched discs. Of course, if the disc is heavily scratched, after resurface, you will still see some hairlines scratches but still 100 times better

[Console Repair/Mod Center / Re: need some advice about repairing a PC Engine Cd Rom2]

Yes, replace those 4.7uf caps will help. I have couples cdroms are fixed by replacing all 4.7uf cap.

[Console Repair/Mod Center / Re: REPAIR GUIDE - Laseractive NEC PAC-N1 / N10: Total capacitor replacement chart]

deleted-- please refer to my post in first page 

[Console Repair/Mod Center / Re: Radial vs SMD capacitors on Turbo Express]

having done several TE with SMD ceramic and tantalum caps i assure you they dont add hum, they actually reduce it

i liken can replacement with SMD replacement to all the different "hacks" people were attempting to reduce Jailbars with NEC consoles. It wasn't until Tim Worthington, in my opinion a brilliant electronics engineer, approached the problem from a fundamental electronics point of view that we now have (what I believe to be) a universal solution (with explaination) to that problem.

When another brilliant engineer (Dave Jones) puts out a video explaining why replacing cans with SMD sometimes is a bad idea, and proves it with measurements on oscilloscopes and calculating on the white board using proven electronics equations; I listen.

I just wanted to bring this up because there are some really good modders out there, but it doesn't mean they're good electronics engineers that can design circuit boards from scratch. I for one know I c

having done several TE with SMD ceramic and tantalum caps i assure you they dont add hum, they actually reduce it

I just wanted to bring this up because there are some really good modders out there, but it doesn't mean they're good electronics engineers that can design circuit boards from scratch. I for one know I couldn't.

Unfortunately,  we need a good modder in this forum because you/we are in "TG/PCE Repair/Mod Discussion" forum. I do understand most of us are not good engineer but our goal is simple  ---> repair and mod pc engine / tg

People(or modders in your term) in here indeed help tons of people to repair their consoles, from bring them back to alive , reduce the hum, etc... We all know they are not rocket science or not backup by tons of engineers who got PhD.  However, the bottom line, it works. Sorry that this forum is people want to share their repair/mod experience and help each other which  you may  feel this is not academic enough.
 
Just share what I feel and to be fair

[Buy/Sell/Trade / Re: WTB Power switch piece for TurboExpress or GT]

Cool TYVM!!
 
Wish there was a like option for me to click.

Found one. Pm me your address.

Free switch and free postage if using regular airmail.
Free switch and usd 2.5 postage  if using registered airmail.

Thanks
Jimmy

[Buy/Sell/Trade / Re: WTB Power switch piece for TurboExpress or GT]

I have spare I think. Let me search it and give you for free if I am able to find it. Will get back to you

[Console Repair/Mod Center / Re: Pc engine cdrom washer clip for middle gear]

Sure. Let me know if you need it and pm me your address

Thanks
Thanks, Jimmy!

Getting ready to swap my first middle gear!  I may need one if I wind up losing mine!

[Console Repair/Mod Center / Pc engine cdrom washer clip for middle gear]

Hi All,

  I recently bought and punch hole tools which can make the Pc engine cdrom washer clip for middle gear based on barley paper easily. Let me know if anyone needs it.  I can send out for free.


Thanks
Jimmy

[PCE/TG-16|CD/SGX Discussion / Re: Help troubleshooting CDROM2]

I'm seeking for some ideas on how to repair my NEC CDROM2. When I first got it, testing it as a CD player with no briefcase attached, I would only get a 0 displayed on the LCD, but no movement. I have changed the middle gear and greased the spindle. Now the CDROM laser moves correctly and I can hear it focusing, but the CD won't spin.

My ideas are:
- possible PSU not delivering enough power (I'm using an universal PSU)
- broken laser block (how to check for this?)
- needed potentiometers adjusting

Any ideas on how to troubleshoot it?

Thanks a lot for any help

Try to replace some 4.7uf/3.3uf capacitors first to see it helps or not. I encountered few cdrom units with bad capacitors.

[Console Repair/Mod Center / Re: LaserActive Pac-N1 got white screen]

The problem is huc6280, once replaced, everything works fine. Thanks thesteve for the hint!!!! He is hero

[Console Repair/Mod Center / Re: LaserActive Pac-N1 got white screen]

replaced those ram(fro spare part) but still No luck. If I replace those HuC62X0 chip, which one I should try first?