REPAIR GUIDE - TurboExpress: Total Capacitor Replacement Chart

[Alexander78]

my Pc-Engine Gt  has the sound down and the delay of the screen.

The electrolytic caps that I did solder on the board were of the same value as the original.

Some new caps explode because the caps in the originals time they released the liquid on the board or perhaps the my board is damaged. But how can I tell my technician to indicate where my board is damaged ?

thesteve, how can I resolve ? only with a cleaning ?

Please... What should I tell my technician do to solve the problem ? ?

[thesteve]

if you used tantalum caps they are often marked reverse to the ones originally used.
even a damaged board would not cause the caps to explode.
as for the video delays, the screens of the time were not that great, and veried considerably from one to another.
the caps can cause some screen issues, but are often not the issue.
try using a headset for a better idea of the sound functionally

[Alexander78]

The caps that were used are "electrolytic type", what do you advise me to do thesteve ?
What information should I give to the technician ?
He replaces the caps and some explode....

only putting "the original old's the caps"  work ,  but the audio and video are not normal.


I do not understand how to find a solution to the my problem.
What would you do ?

[thesteve]

some good pics would be helpfull (pics of the board and the video defect)

[Alexander78]

thesteve ok, I would have pictures to show you...
 
thesteve how I can send you pictures of the my board in this forum ?
(I do not see the tool to insert the image in my posts)

can you tell me how to insert the picture ?

[thesteve]

if you hit the reply button it opens the full post editor

[BlueBMW]

Its usually easiest to host the pictures on another site like photobucket and then link to them here.

[Alexander78]

some good pics would be helpfull (pics of the board and the video defect)

thesteve ok, start to post link pictures ....

The PC engine now is in the lab by my technician, the photos that I have right now are all shielded in the board....

I hope that these photos can help you to understand my problem, I do not know if my board is to clean or is damaged ....

I can not do the video .... because my pc-engine Gt is in a laboratory by a technician who does not know what to do. However, when you turn on my pc-engine Gt the screen is black after a few minutes then slowly stabilizes the image screen and you can see well with good colors, Instead the audio
is very low but with headphones you feel better.

I post link my images....


link Photo high-resolution

/photo8upk.jpg

other link Photo Board high-resolution

/photo3var.jpg


other link Photo

/photo4iz.jpg


other link

/photo5ry.jpg


Even if they are photo with board  shielded I hope that can help.

[thesteve]

hmm i was hoping for the after pics.
that does not look bad at all (should have been a simple cap swap to fix it)
the real question is what damage was done during the cap swap

[Alexander78]

thesteve what do I do....  I do not understand almost nothing about electronics.
Maybe solve this problem, is like finding a needle in a haystack.
The same capacitors are used with the same values and see some capacitors that explode when they are replaced it is not normal.

my technician wants information, what can I tell him to do  ? ? ? ? 
   
( thesteve aspect  your advice, to put it to my technician to try to solve my problem )

[thesteve]

its not normal for the replaced ones to explode.
it took many years for the original caps to fail, the same can be expected of the replacements.
the slow pic is likely due to cap failure, however its possible for the lamp to fail as well.
the sound circuit will need to be traced out to solve it, as it appears to no longer be an issue covered.
fortunately the sound circuit is very strait forward, any electronics tech should have no issue trouble shooting it.
the speaker is driven off the headphone jack directly.

[Alexander78]

ok thank you,  thesteve

[constantt]

Dear All,

Thanks for your contribution on repairing PCE GT/TE! 

I've already successfully fixed the sound problem with replace the 16V 100uF cap.  However, I've also experienced the dark screen problem on my GT & I've tried to reaplce the 35V 4.7uF cap with a 50V 4.7uF (since I cannot find a 35V 4.7uF cap anymore).  The back light came back, however it's going too light, even I adjust to the lowest brightness, it's still too light.  Any suggestion on this?

Looking forward to your reply

Best Regards
Constant

[HercTNT]

mouser or digikey should have the capacitor your looking for.  Ask thesteve about the backlight, he recently repaired a gt for me and can most likely help.

[BlueBMW]

Dear All,

Thanks for your contribution on repairing PCE GT/TE! 

I've already successfully fixed the sound problem with replace the 16V 100uF cap.  However, I've also experienced the dark screen problem on my GT & I've tried to reaplce the 35V 4.7uF cap with a 50V 4.7uF (since I cannot find a 35V 4.7uF cap anymore).  The back light came back, however it's going too light, even I adjust to the lowest brightness, it's still too light.  Any suggestion on this?

Looking forward to your reply

Best Regards
Constant

If the screen is staying too bright even with the contrast adjusted all the way down, its usually because your batteries are almost dead.  Try a fresh set and see if that makes a difference!

[constantt]

Dear All,

Thanks for your contribution on repairing PCE GT/TE! 

I've already successfully fixed the sound problem with replace the 16V 100uF cap.  However, I've also experienced the dark screen problem on my GT & I've tried to reaplce the 35V 4.7uF cap with a 50V 4.7uF (since I cannot find a 35V 4.7uF cap anymore).  The back light came back, however it's going too light, even I adjust to the lowest brightness, it's still too light.  Any suggestion on this?

Looking forward to your reply

Best Regards
Constant

If the screen is staying too bright even with the contrast adjusted all the way down, its usually because your batteries are almost dead.  Try a fresh set and see if that makes a difference!

Hi BlueBMW,

Really thanks for your help & it's work perfectly after I changed the battery!!  Sorry for boring you guys!!

Best Regards
Constant

[NightWolve]

** Organized TurboExpress Part List (4-27-2012)

Qty.	Part #	Description	Price	Ext. Price
6	493-2088-1-ND	"CAP ALUM 100UF 6.3V 20% SMD"	0.44	$2.64
3	493-2105-1-ND	"CAP ALUM 100UF 16V 20% SMD"	0.47	$1.41
2	PCE3859CT-ND	"CAP ALUM 33UF 6.3V 20% SMD"	0.49	$0.98
1	P5114-ND	"CAP ALUM 470UF 6.3V 20% RADIAL"	0.25	$0.25
1	493-2118-1-ND	"CAP ALUM 22UF 35V 20% SMD"	0.51	$0.51
1	493-2083-1-ND	"CAP ALUM 22UF 6.3V 20% SMD"	0.50	$0.50
1	493-2099-1-ND	"CAP ALUM 10UF 16V 20% SMD"	0.48	$0.48
1	PCE4304CT-ND	"CAP ALUM 4.7UF 50V 20% SMD"	0.71	$0.71
1	PCE4643CT-ND	"CAP ALUM 4.7UF 35V 20% SMD"	0.50	$0.50
1	P1142-ND	"CAP ALUM 47UF 6.3V 20% RADIAL"	0.30	$0.30
			Subtotal	$8.28
			Shipping/Tax	~$3.22
			Total	~$11.50

Eh, I decided to move over most of this post to my own thread:

https://www.pcengine-fx.com/forums/index.php?topic=11660.0

[Frank_fjs]

Need some help guys, very confused at the moment.

Trying to work out which caps would be best, should I go for all SMD Tantalum or is that overkill and should I just use aluminium caps instead?

I see that Steve has mentioned using ceramic caps but I can't work out where these should be used, he seems to use a combination of both Tantalum and ceramic?

Also, if someone has the time, could you tell me if these are the right parts?

4.7uF 35V: http://au.element14.com/nichicon/f931v475mcc/capacitor-tant-4-7uf-35v-1-8-ohm/dp/1818596
4.7uF 50V: http://au.element14.com/vishay-sprague/593d475x9050d2te3/capacitor-tant-4-7uf-50v-0-6-ohm/dp/1614982
10uF 16V: http://au.element14.com/nichicon/f931c106mba/capacitor-tant-10uf-16v-2ohm-3528/dp/1818581
22uF 6V: http://au.element14.com/nichicon/f930j226maa/capacitor-tant-22uf-6-3v-2-5ohm/dp/1818568
22uF 35V: http://au.element14.com/vishay-sprague/293d226x9035e2te3/capacitor-tant-22uf-35v-0-6-ohm/dp/9303669
33uF 6V: http://au.element14.com/vishay-sprague/tr3a336k6r3c0600/capacitor-tant-33uf-6-3v-0-6ohm/dp/1615383
100uF 6V: http://au.element14.com/nichicon/f910j107mcc/capacitor-tant-100uf-6-3v-0-25ohm/dp/1818563
100uF 16V: http://au.element14.com/vishay-sprague/tr3d107k016c0100/tantalum-capacitor/dp/1616462
470uF 6.3V: http://au.element14.com/kemet/t495d477k006ate100/capacitor-tant-470uf-6-3v-0-1ohm/dp/1642274

Perhaps a better question to ask, does anyone here sell cap kits for the GT?

[NightWolve]

Definitely go for ceramic/tantalum if you're willing to spend the extra dough. You'll eliminate that very apparent hum in the audio if you avoid standard, electrolytic aluminum caps like I used... Yeah, forget my list above there which are for the original SMD aluminum types which are harder to solder back on. Ceramic ones you won't have to worry about polarity and tantalums you will.

[Frank_fjs]

So you can use ceramic caps for all of them?

As an example, for the 4.7uF 35V cap, is this what I'm after?

http://au.element14.com/taiyo-yuden/gmk316f475zg-t/capacitor-4-7uf-35v5v-1206/dp/2112843?in_merch=New%20Products

or

http://au.element14.com/taiyo-yuden/gmk325bj475mn-t/capacitor-ceramic-4-7uf-35v-x5r/dp/1683538

Not really sure what the difference is between the above two caps, aside from price and temperature range. Does it matter which one I get?

[NightWolve]

If you can find them. I found everything in ceramic for my SNES, but they cost more. They used to only cover very small capacitance values, but now you can get them in average values, never as high as aluminum though.

http://www.digikey.com/product-detail/en/C2012X7R1V475K/445-7555-1-ND/2733627

There's one, .70 cents. Seems all surface mount only though. I soldered two of them on, not hard if you prep it.

In the case of the two that you're looking at, I see a size difference. One is smaller than the other, so it's just a matter of space. It's helpful if you measure the spacing where the old aluminum one is and buy one that's about the same length so you don't have to do tricks with extra solder to install them.

[sparkychan]

Like many have said before, thanks to all that helped with the creation of the chart and providing their technical knowledge to this thread. I am going to begin the process of replacing all the capacitors in my Turbo Express. One question I had was how most remove the white epoxy-like substance near the large 100uf  capacitors? I'm having trouble exposing the solder points for the capacitors.

Any help would be appreciated.

Thank you!

[NightWolve]

Yeah, that was hard. I used a fresh razor blade for that.

[thesteve]

sharp knife here

[sparkychan]

Thanks for the replies. Ugh, I think my attempt was too aggressive and may have chipped the component that is concealed by the epoxy. Does anyone know what the component is that is underneath the epoxy?

[thesteve]

its a choke (coil of wire)

[Frank_fjs]

Any reason why I couldn't use a 'Tag Tantalum Capacitor' in a few spots ?


https://www.jaycar.com.au/47uf-16vdc-tantalum-capacitor/p/RZ6670

I can get them locally for quite cheap, specifically:

4.7uF 35V
33uF  6V

^ Seeing as these relate to audio/video I thought it might be better to use the Tantalums here.

Can also get the '10uF 16V' & '22uF 6V' in a tag tantalum but am not sure if there's a benefit to doing this, what are these caps responsible for anyhow?

I was planning to use standard electrolytic caps for the rest, just for the sake of cost/availability and ease of install.

[thesteve]

yes you can use them, but uprate the voltages on most

[maverick1978]

Does anyone sell ceramic/tantalum cap kits for the TE? - I can find all the radials I need, but searching through other types of caps really confuses me (electronics newbie here, though I can solder pretty much anything)

[thesteve]

i use size 1206 ceramics (they fit well)
a ceramic is non-polarized (can be installed either way)
ceramics handle ripple well (no need to use higher voltage ratings)

[NightWolve]

yes you can use them, but uprate the voltages on most

Hey steve, pretty much every capacitor just needs to be above 16 Volts, correct ? All capacitors could be replaced with 16 Volt or better models as long as the capacitance value matches, right? That is how I have understood things. I mean, 10 Volts comes into the motherboard, the regulator steps the voltage down to 5V for most operations, etc. there is never anything that steps the voltage back up, is there ? Since the power supply is not a more expensive well-regulated one, you do have 13 Volts, not ~10 Volts exactly coming in, but yeah, as long as everything is 16V or above, it'd work fine, right ???

See, I made the mistake in believing I had to match the voltages exactly as well when I ordered the caps for my Express... But I could've purchased all of them as 16 Volts or above... All that happens with higher voltage rated caps is that you pay more and they're bigger, but as long as the capacitance value is the same, they'll function the same, isn't that pretty much the case ??

ERR: I was asking about a Duo, hence the 10V rated power supply coming in, but same deal with an Express that has 7V coming in... which in that case, everything probably could be a 10V rated cap at the minimum, but probably still better to have all 16V rated ones, eh?

The one real question I'm asking is, could I just buy ALL caps at 16 Volts or what, ALL caps at 25 Volts to avoid this "ripple" concept you're mentioning ?? What is the ONE minimum voltage breakdown rating that I could buy for ALL capacitors on the board ??

[thesteve]

on the duo no step-up, however the express does use 2 inverters producing higher voltages.
check the voltage across the cap before subbing it

[NightWolve]

Aaaaah, OK, so there is a "step-up" in voltage at times, via what you're referring to as an "inverter," hence the max voltage rating that the manufacturer chose matters in such an instance, and you say that is a valid concern when it comes to an Express, but not the Duo. That makes sense. I was thinking, why did NEC put 50V caps over here, then 16V caps over there, when the motherboard operates at 7-10V, why not just get all 16V caps, you know? I figured there's possible spiking or step-up in voltage at times or something.

I answered my other concern about a 3.3uF capacitor for the Duo that's at 50V, that is, real small capacitance values come in high voltages (like ceramics) most of the time, so you don't find 3.3uF at 16V or something, they make 'em mostly at 50V and they're still pretty small for electrolytic aluminum type. Something Red Ghost had said made me think there was a spike in voltage for that 3.3uF, but that's not the case for the Duo as you say; it's just that small micro-farad value caps generally come in 50V ranges like under 47uF. The closer the capacitance value is to the traditional ceramic range for an electrolytic, the more likely it can handle 50V, etc. Seems like.

Well, I think I understand the rest of my concerns now although I'd like to hear more about this "ripple" concept you mentioned and how that should guide the substitution. Danke!

[thesteve]

ripple causes heat
ripple can also damage polarized caps when the discharge current causes a polarity flip internally

[NightWolve]

Hence why AC non-polarized ceramics are better. Gotcha. Well, I had a bad experience when I switched to all ceramic with my SNES, so now I'm paranoid about going that route. Blew $11 bucks and then I switched back to cheap electrolytic anyway.... 

[bust3dstr8]

Text version for the people that prefer this style

https://console5.com/wiki/Turbo_Express#Capacitor_List

CC100   100uF   16v
CC101   33uF   6v
CC102   33uF   6v
CC103   100uF   6v
CC104   100uF   6v
CC500   100uF   16v
CC501   4.7uF   35v
CC502   4.7uF   50v
CC503   22uF   35v
CC504   100uF   6v
CC505   100uF   6v
CC700   100uF   6v
CC702   470uF   6.3v
CC703   100uF   6v
CC704   10uF   16v
CC900   100uF   16v
CC901   22uF   6v

Controller PCB Cap:
CC800   47uF   6.3v

[cosmos99]

Here is the parts number listing at Digikey , note that those are exactly the same as used in the GT/TE or close when unavailable,none of those is bigger, some just shorter in height wich is not a problem:

Surface mount:

3 x 100µF 16v PCE3879CT-ND
6 x 100µF 6v PCE3852CT-ND
2 x 33µF 6v PCE4560CT-ND
1 x 22µF 35v PCE3952CT-ND
1 x 4,7µF 50v PCE4304CT-ND
1 x 4,7µF 35v 565-2114-1-ND
1 x 10µF 16v 565-2442-1-ND

On holes:

1 x 470µF 6.3v 399-6611-ND
1 x 47µF 6.3v P957-ND

[override]

Nice to see this forum is still kicking! Whats up nightwolve, been a LONG TIME

[NightWolve]

Nice to see this forum is still kicking! Whats up nightwolve, been a LONG TIME

Hey there! Uh, did I know you by another alias? override doesn't ring a bell.

Hence why AC non-polarized ceramics are better. Gotcha. Well, I had a bad experience when I switched to all ceramic with my SNES, so now I'm paranoid about going that route. Blew $11 bucks and then I switched back to cheap electrolytic anyway....  

I thought I'd mention an update while I'm at it with regards to this. I believe I figured out the problem when it comes to replacing standard aluminum caps with high-capacitance ceramic equivalents. First off, I highly recommend that everyone purchase a Digital Multi-Meter that can measure capacitance for cap replacement jobs. Very important I think! I'm extremely happy with the Vicky VC99 I recently purchased that can measure caps as small as 40nF.

OK, so anyhow, here's why it's important to have this feature: every cap in your kit has a different value than what is stated, ceramics are usually a lot lower and aluminums are usually somewhat higher. If it's a 100uF cap, if might actually read 120uF or 95uF, all varies. So before you replace a cap with a new one, you can test each one with a good DMM (if you get one) and pick out the best from the lot that you bought! Not all are created equal, etc.

Now, here's the deal with what happened with my SNES. I bought 2.2uF, 10uF and 100uF in ceramic. Expensive, but hopefully lifelong and would never leak, so cool deal right? Well, after doing a full replacement, it looked like everything was working fine, but when I tried Super Street Fighter II, when Ryu does his opening fireball and the screen goes *full* white and bright, the TV would lose sync and right before at the top, it'd look like say what electricity would, etc. I played around using a resistor in between the Luma output which would fix it, but you'd lose the perfect contrast that the SNES outputs because the thing has a rock-solid Luma to begin with and doesn't need to be messed with... Not an acceptable solution.

Anyway, I finally got sick of this, and I declared all of these high-value ceramic caps a big mistake, and I had paranoia in ever using them again. So I put new aluminum caps back in place and everything worked fine again! However, after my new VC99 DMM arrived, I tested all of the ceramic caps that Digikey had sold me (I blew $11 bucks after all!). Here were the results: the single 2.2uF cap came out to 3uF, the 10uF caps were 9.3uF - 9.5uF, BUT, the 100uF caps were like 64uF!!!! They were off by fucking 40% from the stated value, WAY unacceptable and those were the caps that caused the problem! The Luma/Y amplifier circuit on 1st generation SNES systems has a 200uF cap before going to the Multi-AV out to kill off the remaining 1.35 Voltage. 2 100uF caps are connected in parallel for this. Anyhow, as a result, I put the small 2.2uF and 10uF ceramic caps back on the system and I left the 100uF caps in aluminum...

So, ProTip: Stay away from high-value ceramics (above 10uF) or get a DMM that can measure them for you so you don't get fucked by one that's way way too low from the stated value!!!

The other thing: Digikey sent me a notice that TDK discontinued manufacture of most of the caps that I had bought from them for this SNES job... (I was like, thanks a lot, assholes!) So yeah, my experience may not be reflected by anyone else and any general rules may not apply. Nonetheless, I don't trust a new cap now unless I can pre-measure it before soldering it on and I wanna be able to pick out the best ones first out of the package... The Vicky VC99 allows for this, get it! Then throw another dollar to this Chinese seller for the alligator clips, so you can clip on the leads to a cap for easy testing, and you're all set (it doesn't come with them).

* Discontinued ceramic cap in question (100uF 6.3V):

http://www.digikey.com/product-search/en?x=17&y=14&lang=en&site=us&KeyWords=445-4827-ND

TDK's stated reasons: http://media.digikey.com/pdf/PCNs/TDK/Dipped_Y5V_Disc.pdf

I bought 4 of those fuckers, and they were ~60-70uF, VERY far off! The aluminums are usually higher than the stated value is what I am finding with my cap measuring DMM.

[thesteve]

the caps are typically allowed 20% unless stated otherwise
your caps were off over 50% and should be considered defective.
i have only used 22uf and lower in ceramic and 100uf tant
the ceramics are more forgiving than tant, and preferred.
often aluminum will be rated @ -20%+80%

[RTQ]

Steve,

I ordered an entire set of aluminum capacitors to fix my TE before finding this site.  I want to reorder everything ceramic now.  Are you saying to just use ceramic ones up to 22uf and then use aluminum over 22uf?  Or can I use ceramic to replace them all?

Should I get the exact Volts with ceramic?  If not, how many volts higher is within allowable range?  Thank you very much!

First Post!

[BlueBMW]

You can go with higher voltage as long as size doesnt cause an issue.

[NightWolve]

RTQ, this is a key point once made by steve: if you can replace all capacitors with tantalums or ceramic on a Turbo Express, you can eliminate the humming sound in the speakers and headphones (it's more pronounced I recall when using headphones).

You can get all values in ceramic at Digikey and the other place that's linked here (mouser, I think), but I am nervous that the values above 10 uF or more will be of lower capacitance than the stated value. I'd bet that's not the case with tantalums, though. Like, if they have a 120 uF ceramic capacitor, I would buy that one and use it for the 100 uF replacements - that'd be my advice... Would be good if you have a DMM that can measure capacitance so you know what's going on exactly... but yeah, point is, the actual capacitance value of a ceramic capacitor is usually lower than what it says it is... While some aluminum caps can be actually higher (significantly sometimes) than the stated value...

As for voltage, the higher the better as Blue says, but that means the capacitor will be bigger, thus take up more space, plus it'll be more expensive! They'll last longer too, being better able to handle "ripples" as it's referred to. Anyway, go 35V+ if you can in ceramic and see what the price is, etc. Ceramics are much smaller compared to aluminums, so I doubt you'll have spacing issues even with the 100 uF ones that you need for a TE.

[Slypty]

Some great info in this repair forum, I'm about to undertake repairing a PC Engine GT, it has no Sound but the video is fine and works well other than that.  I think it's worth the overhaul to put in new caps before something bad happens.

  Anyways, I was wondering if anyone can confirm that the same caps are used in the PCE GT?  I suppose I could just open it up and check, just a bit lazy.  Thanks

[thesteve]

the gt and te use the same main board and controller
all parts match except the te has a 0ohm resistor to bypass region check

[ltpitt]

I have been able to (finally) fix my sound thanks to all this precious info.

My soldering skills completely suck so I want to spend a few words to give courage to other friends out there

I had to train because I didn't want to wreck my precious PC Engine so I decided to throw a bit of money into that.

This silly thing helped me a lot:

https://www.futurashop.it/index.php?route=product/product&path=4025_3193_303&product_id=3664

If you're able to deal with this repairing the Pc Engine will be a piece (almost) of cake.

If you are lazy and / or afraid to make mistakes when buying parts a kind french guy sells the whole kit:

http://www.otakus-store.net/en/nec-pc-engine/230-smd-full-cap-kit-for-pc-engine-gt-turbo-express.html

Be sure to grab a third hand and a nice magifier and PATIENCE.

Lots of it.

You can kill your little fellow if you don't abuse of your patience.

Thanks to all the electronics heroes that made my work possible: you are awesome.

[mickcris]

Couple of dumb questions:

When removing the white epoxy from the inductor, i exposed part of the windings.  Just wondering if I need to cover back up with something?  Not sure what the purpose of it was originally.

Also, can you replace 2 through hole caps with ceramic/tantalum?  I mostly saw in this thread talking mainly about the surface mounts being replaced with them.  Don't think these would be any different though, but not 100% sure.  The through hole cap on my controller board seems to be the one that has leaked the worst.

thanks.

[Keith Courage]

Make sure the wiring for the inductor is still connected to its traces on the board. Sometimes when uncovering it one end can snap off. I've used a two part epoxy to cover it back up in the past when I've accidentally uncovered it. Not sure if it needs it but it can't hurt anything to cover again. I'm sure hot glue would work nicely as well.

Use any kind of caps you want.

[Nazi NecroPhile]

I'm sure hot glue would work nicely as well.

Thanks for the tip, Drakon. 

[NightWolve]

I love hot glue, for the record.  So damn useful!