Author Topic: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart  (Read 10741 times)

Echoes

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #225 on: January 03, 2021, 06:33:58 PM »
Does anyone have the values for the capacitor that should be in the spot marked C001? It seems to be missing on the Duo I picked up and that one doesn’t seem to be listed on most charts I can find.

Keith Courage

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #226 on: January 03, 2021, 07:51:29 PM »
Is this for a pc engine duo? There is one spot on the board that is missing cap from the factory and is supposed to be like that.

Post a picture of the spot on the board here and I'll let you know.

Echoes

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #227 on: January 03, 2021, 08:55:40 PM »
Is this for a pc engine duo? There is one spot on the board that is missing cap from the factory and is supposed to be like that.

Post a picture of the spot on the board here and I'll let you know.

It's a US Turbo Duo, the spot is the white circle right there by the corner of the drive.

https://ibb.co/jVvmMrw

Keith Courage

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #228 on: January 05, 2021, 07:07:24 AM »
Oh, that cap isn't important at all. Some systems don't even have one there leaving the solder points empty. I'll check what the rating on the cap when I have another DUO opened up. I know it's a ceramic cap but forgot the value.
« Last Edit: January 05, 2021, 07:12:28 AM by Keith Courage »

demianph

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #229 on: September 21, 2022, 09:55:25 AM »
Is this for a pc engine duo? There is one spot on the board that is missing cap from the factory and is supposed to be like that.

Post a picture of the spot on the board here and I'll let you know.

It's a US Turbo Duo, the spot is the white circle right there by the corner of the drive.

https://ibb.co/jVvmMrw

Sorry for the necro but so the information is available I am replying.
Have mine open to re-cap (I found 5 definitely leaked surface mount caps).

Mine was manufactured October 1992 and has the cap.
Markings are:
   B
103K
symbol that looks like a M inside a C (manufacturer mark maybe) then 03

Internets say this is 10000pF (.01uF) with a +/- 10% tolerance and voltage is 50/100 volts (the underline). I think the B is the temperature code or flammability rating which it appears no one uses anymore.



qingtongyoushou

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #230 on: November 15, 2022, 09:05:13 AM »
I am helping my friend fix his PC-Engine and this is very useful information :D

game freak99

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #231 on: November 15, 2022, 02:37:07 PM »
I got a PC engine Duo that still has sound issues despite having what looks like a new set of caps. Do any of them look like the last owner missed them?

https://imgur.com/a/c7tbzPh

Keith Courage

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #232 on: November 15, 2022, 04:22:38 PM »
Just changing out the capacitors is only part of the work. Lots of times there are damaged traces and or shorts in via holes that need to be repaired during a capacitor change. This is most likely the problem as to why you are still having sound issues.

So the connections for the capacitors need to be checked to make sure the traces all have continuity and that the via holes have the correct continuity through them as well.

there is also the possibility of some old capacitor fluid being underneath one or more of the op amps or even possibly some of the resistors on the board.
« Last Edit: November 15, 2022, 04:26:32 PM by Keith Courage »

game freak99

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #233 on: November 15, 2022, 08:52:07 PM »
I just got a set of opamps in the mail today so I'm going to replace at least the one closest to the power regulators.

On the subject of the power regulators I'm reading 12v from the leg that feeds the opamps and supposedly it should be  only 8v. Then the transistor that is between the power regulator and the opamps is only outputting 1.6 volts. Do any of those parts sound like a likely culprit to you?

Keith Courage

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #234 on: November 15, 2022, 09:33:20 PM »
One pin should be around 12-13v and another 5v.

If the voltage regulators weren't putting out the correct voltage, either card games or CDs wouldn't be working at all. so the voltage regulators are probably fine.

There's probably a bad trace,shorted via hole, or old capleakage under an op amp somewhere in the area above the heat sinks.

game freak99

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #235 on: November 15, 2022, 11:42:24 PM »
That makes sense. Could there be something wrong with q304 making it only output 1.6 volts instead of 7-8 like it's supposed to? Or maybe something upstream from pin 1?

Also, when I first tested the unit there was extremely quiet sound, but after I washed the board with 99% isopropanol (lots of brown gunk on my qtips!) there was none. Could I have loosed up some capacitor gunk from the board and ended up getting it into worse places?

Thanks for your advice!

djbunyan

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Re: REPAIR GUIDE - TurboDuo/PC Engine Duo: Total capacitor replacement chart
« Reply #236 on: January 07, 2023, 07:20:14 PM »
Hello! Is anyone in here willing and able to help me fix a PCEngine Duo?