REPAIR GUIDE - TurboExpress: Total Capacitor Replacement Chart

BlueBMW · 06/09/2011, 01:04 PM

I always do all the caps. Every time I removed any of the other caps I find leakage. While it might not manifest in audio or video issues, you know eventually the leakage will corrode something important and cause system failure. There aren't many caps on an express so there really is no reason to not do them all if you've got it apart.

thesteve · 06/09/2011, 03:09 PM

i just changed my 16V caps
leakage was present and the picture got more vivid

daedalia · 06/22/2011, 11:04 AM

Replaced all the caps in my PCE GT and just want to say thanks to all those who contributed. Used surface mounts thanks to marshalh, first time and fairly easy to solder, practiced on an old video card.

With regard to doing all the caps; I'd recommend it. While working on mine I accidently breathed on a few and they flew off. Not only leaking but they were badly corroded too, took a bit of prep to sort the contacts out. Miraculous the unit worked at all. So I'd say if you are going to open it, you may as well do them all. All of mine were fooked.

Keith Courage · 06/24/2011, 03:30 PM

I have already replaced the necessary audio caps on my turbo express. However, I was thinking about trying some 47UF instead of the 33UF to make it a little louder as stated in the cap replacement chart. Has anyone ever done this? Is it safe and are there any long term problems if done this way?

thesteve · 06/24/2011, 05:20 PM

i use 47's on all mine

BlueBMW · 06/24/2011, 07:41 PM

As do I. Saves me from having to order 33uf caps

blueraven · 06/29/2011, 09:04 PM

Attached photo of a full silver cap replacement with NTK Hi-Temp capacitors on a PC Engine GT. The 100uf caps are really bad on these, so be really careful removing the three right next to the 33/47uf sound caps.

I have already clearanced the caps for re-assembly, so if you organize and place them similarly to how I have in the picture, the unit will go back to together without any major issues.

Also, when re-attaching the board to the plastic backing, make SURE to put a screw (you have 3 and 4 holes) in the Top Right hole, where all the traces shroud around, or the hu-card will stick out and you will have to hold it down when you flip the power switch.

I keep this chart open on my screen every time I repair one of these

thesteve · 06/29/2011, 10:09 PM

I printed the chart, and work from the paper.
when using caps with wires, surface mounted like that you should use some silicone calking to glue them in place.

boliver · 08/04/2011, 07:30 AM

hi, I have a broken turbo express. i accidentally hooked up a 12 volt power adapter to it, now its completely dead when i put games in or when i turn on the tv tuner. only the lcd backlight still works. i was wondering if i could pay someone to look at it.

thanks!

thesteve · 08/04/2011, 10:31 AM

pm sent

farankoshan · 08/28/2011, 05:16 PM

My TurboExpress won't even boot up anymore (no sound, no audio, and seemingly no power). Will a total replacement of the caps solve that problem?

BlueBMW · 08/28/2011, 05:23 PM

Its possible... but if it is because of caps, its very likely you'll have to repair some traces and maybe some other components that have been damaged by leaked capacitor fluid.

farankoshan · 08/28/2011, 05:39 PM

I will begin the long road to raising this baby from the dead.
Hopefully, my efforts will not be for naught.

BlueBMW · 08/28/2011, 06:03 PM

Quote from: farankoshan on 08/28/2011, 05:39 PM I will begin the long road to raising this baby from the dead.
Hopefully, my efforts will not be for naught.

If you fail, one of us can surely fix it

farankoshan · 08/29/2011, 01:45 AM

Hey thanks, BlueBMW!

I do hope it's capacitor-fixable for now.

(Is it just me, or is Red Ghost's chart and diagram lacking...?)

BlueBMW · 08/29/2011, 07:46 AM

Quote from: farankoshan on 08/29/2011, 01:45 AM(Is it just me, or is Red Ghost's chart and diagram lacking...?)

Lacking in what way? It shows all the capacitors that tend to fail. The solid surface mount capacitors dont have the same problems that the aluminum electrolytics do.

farankoshan · 08/31/2011, 03:37 AM

Does anyone know where I can source a replacement for the transformer that powers the screen lamp? Mine shorted (due to cap leakage) and I'm not sure where to find a replacement...

BlueBMW · 08/31/2011, 07:28 AM

The best bet would be from a junk express / gt. Shoot username Duo_R a pm. I seem tobrecall he may have a few completely dead or severely damaged expresses.

phipscube · 09/12/2011, 09:58 AM

This is a fantastic Guide!! I recently bought a PC Engine GT and it had very weak audio and washed out colour. I did a full cap replacement and its now working great! nice loud audio (I used 47uF caps on the audio section) and much nicer colour

The only thing that i'm a bit gutted about is the screen has a dead pixel appear after I did this. I was very careful with the top shell/display but for some reason when I assembled the unit the dead pixel was there. Not a REALLY big deal as it's not noticable when playing, but i'm a bit of a perfectionist so it bugs me a bit when the screen is black.

BlueBMW · 09/12/2011, 10:31 AM

Finding an express without a dead pixel is hard. They almost all have at least one dead pixel.

phipscube · 09/13/2011, 02:25 AM

Ah ok, I thought I could have done something to make it appear. Just coincidence I guess

thesteve · 09/13/2011, 03:42 AM

of the 5 i think, expresses i have worked on, only one has a dead pixel. PS. its one of mine
even TZD listed dead pixels as common, and nothing to be concerned with

BlueBMW · 09/13/2011, 10:13 AM

So that's where all the good expresses are..

stevs been hoarding them

farankoshan · 09/13/2011, 02:15 PM

please send one my way... hehehe.

My Express is now just a glorified bit-tunes player for Turbografx music...

thesteve · 09/13/2011, 02:20 PM

i only have 2, 1 with a perfect screen.
the other perfect screens i have seen were units i fixed for others. (all the ones fixed for others)

farankoshan · 09/13/2011, 02:23 PM

Quote from: thesteve on 09/13/2011, 02:20 PMi only have 2, 1 with a perfect screen.
the other perfect screens i have seen were units i fixed for others. (all the ones fixed for others)

One day, stevo!

One day! You've helped me so much over this thread, man... but, yeah, I have to send my dead-screened Express to you one day.

Until then, I've managed to get to the Sound Test debug of Blazing Lazers, purely on audio alone... good tunes. Gotta admit, the TurboExpress still does that job right with the great 47uF caps doing their job. ;)

phipscube · 09/15/2011, 04:06 AM

I wonder if there is a way to make dead pixels work again on PCE GT/TGE?... Mine is sometimes a colour, not just black, so i'm wondering if its just a bit "stuck". I've seen programs that flash flat colours quickly to bring back stuck pixels on PC monitors. It would be cool if some kind of homebrew program existied for PCE to try this (loaded up on a flash cart of some sort like the Neo Power 128M).

Nazi NecroPhile · 09/15/2011, 09:57 AM

Quote from: phipscube on 09/15/2011, 04:06 AMI've seen programs that flash flat colours quickly to bring back stuck pixels on PC monitors. It would be cool if some kind of homebrew program existied for PCE to try this (loaded up on a flash cart of some sort like the Neo Power 128M).

Rover made such a color cycling program.

phipscube · 09/15/2011, 10:16 AM

That's awesome! I'll give that thread a good read, it looks very interesting, Thanks necromancer

phipscube · 09/17/2011, 07:43 AM

If any of you guys are interested I posted some photos of my efforts replacing my caps over on Amibay where i'm a regular, I also plugged this awesome site a bit ;) : -

http://www.amibay.com/showthread.php?p=212375#post212375

BlueBMW · 09/17/2011, 05:52 PM

Quote from: phipscube on 09/17/2011, 07:43 AMIf any of you guys are interested I posted some photos of my efforts replacing my caps over on Amibay where i'm a regular, I also plugged this awesome site a bit ;) : -

http://www.amibay.com/showthread.php?p=212375#post212375

Nice writeup

That one guy had never heard of a portable PC engine!?

Hopefully that mod chip will arrive soon so you can really be playing in style!

phipscube · 09/18/2011, 12:46 PM

Quote from: BlueBMW on 09/17/2011, 05:52 PM
Quote from: phipscube on 09/17/2011, 07:43 AMIf any of you guys are interested I posted some photos of my efforts replacing my caps over on Amibay where i'm a regular, I also plugged this awesome site a bit ;) : -

http://www.amibay.com/showthread.php?p=212375#post212375
Nice writeup That one guy had never heard of a portable PC engine!?

Hopefully that mod chip will arrive soon so you can really be playing in style!

Thanks mate

Yeah that guy not knowing about a "Handheld PC engine" tsk tsk! Not sure if he was pulling my leg so replied very neutrally.

I do hope the mod chips get here soon, i'm itching to get cracking. Probably not too much longer to wait now

farankoshan · 09/18/2011, 05:04 PM

Congratulations on the fix! It's real good to see GTs/Expresses work just fine after a cap replacement.

farankoshan · 09/20/2011, 01:22 PM

Guys, I just noticed now, and I'm a little confused. On this thread (Turbo Express Cap Replacement Chart), the very helpful chart says that bringing up the 33uF 6V cap to a 47uF 6.3v cap will improve the speaker audio.

But on this thread:
https://www.pcengine-fx.com/forums/index.php?topic=702.0

The audio fix comes from replacing the 100uF 6V caps.

Are they both for audio? Or has one of the guides been made obsolete?

thesteve · 09/20/2011, 02:22 PM

both are coupling caps, in the audio circuit.
33uf are stock.
47uf and 22uf are much more common and both work equally well.

farankoshan · 09/20/2011, 02:52 PM

I see.

Thanks for clarifying, Stevo! Good caps for good sound. Makes sense to me.

This forum continues to be the friendliest, & most helpful NEC-related one around.

Alexander78 · 12/06/2011, 09:39 AM

Hello people ! I'm new, I'm italian, sorry for my english ....

I have a PC Engine GT this guide goes well for the PC Engine GT ?

What type of SMD (caps) should be used ????

What are the best smd caps to use?
( example: polyester, polypropylene or ceramic ? )

thesteve · 12/06/2011, 10:18 PM

ceramic are best.
tantalum come in larger sizes

HercTNT · 12/07/2011, 08:01 AM

With capacitors coming in so many varieties, does one type excel in say an audio environment more than another? Or a game system? and so on.... I guess what I mean is for example, if your gonna recap a hand held console, does one capacitor have an advantage over another? measurable improved battery life or cleaner picture and sound.......

Alexander78 · 12/07/2011, 08:35 AM

Quote from: thesteve on 12/06/2011, 10:18 PMceramic are best.
tantalum come in larger sizes

Thanks thesteve, so ceramic are the best, then I will use these.

I want to replace all smd caps of the my Pc Engine Gt (version jap)

I hope not to do stupid things on the GT.

This tutorial in this forum i think That It Is Also useful for the PC Engine GT (Jap version)
and not only for the Turbo Express, is not it ????

BlueBMW · 12/07/2011, 10:25 AM

The board layout is the same US and JPN with regard to capacitors.

Alexander78 · 12/07/2011, 03:26 PM

the board is identical to Turbo Express, but all smd Also, just?

I'll change all the SMD present in the board

for BlueBMW: is a particular question .... but.... How old you have to wait for capacitors to change of again ???? (about)

BlueBMW · 12/07/2011, 04:15 PM

In theory electrolytics will last 15 years or so, often longer. If you change to solid caps like ceramics they should outlive you

Alexander78 · 12/08/2011, 05:53 AM

ah ok, in theory 15 years ....

but the ceramic caps are not too big to put on the board Pc-Engine Gt ?
I am afraid that the Gt is difficult mount with caps in ceramic.... (they are too large in nature)

if you put small caps smd as the original ones, I would not have trouble closing and mount the two parts Pc-Engine Gt

I want to find, the caps used in the original Pc-Engine GT (Although I know that will not be easy)

thesteve · 12/08/2011, 05:11 PM

look at an earlier post, i have used ceramics in TE.
they are smaller than original

https://www.pcengine-fx.com/forums/index.php?topic=10167.0

Alexander78 · 12/09/2011, 10:11 AM

for thesteve: great post!

incredible these small tantalum capacitors , with these I would not problems in closing and to mount the Gt ....

I asked my local electronics store here in Italy but does not sell them ....

I think they are not easy to find .... (are special)

thesteve, where you found them ? what store ?

thesteve · 12/09/2011, 02:39 PM

ive been getting my ceramics on ebay from the manufacturers in 50 and 100 counts
the tantelum caps im using are the 100uf shown and i bought 1500 of them as new surplus on ebay.
all the parts i used can be bought from most on line electronics suppliers.

Alexander78 · 12/09/2011, 07:43 PM

Thanks thesteve, BlueBMW for the info. ;)

Alexander78 · 12/15/2011, 08:45 AM

Quote from: thesteve on 12/09/2011, 02:39 PMive been getting my ceramics on ebay from the manufacturers in 50 and 100 counts
the tantelum caps im using are the 100uf shown and i bought 1500 of them as new surplus on ebay.
all the parts i used can be bought from most on line electronics suppliers.

Hello thesteve,

I was speechless because I can not understand the problem ...

I did run the operation by a skilled electronics technician

I did replace all the capacitors on the card of my PC-engine Gt (version jap).

Are been welded type smd " electrolytic " capacitors, all with the same value, but I have not solved the sound problem and the delay of the screen.

The technician after who performed the surgery, saw something explode capacitor

I can not understand the problem .... can you help me understand what may be the problem?

I changed all the capacitors, with "electrolytic capacitors smd" putting but I have not solved the problem of audio and video, can you help me ?

(some capacitors are even exploded)

Is there anything else I should check or replace ?

thesteve · 12/15/2011, 12:11 PM

if you have new caps exploding they were too low of voltage rating or installed backwords.
the original caps often explode or leak, requiring the board to be cleaned and sometimes repaired to restore function