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Re: PC-Engine Duo No video mid cap replacement?

Posted: Fri Jan 06, 2017 5:47 pm
by Ziggy587
that1crzywhtguy wrote:Just had a thought... Any chance the combination of some new and some old caps is causing the issue? Should I just complete the cap job and hope for the best?

Maybe that's way off, but as I said, I'm no expert!

:idea: :? :lol: :D


I don't see how that combo would cause the system not to work. If the system was working with 100% of the old caps, it should work after replacing each cap. That is assuming each new cap is the correct value, installed with the correct polarity, and everything else mentioned above.

Of course, I'm not expert either!

Re: PC-Engine Duo No video mid cap replacement?

Posted: Sat Jan 07, 2017 5:45 pm
by ApolloBoy
I would still replace the remaining caps while you're at it, if you continue to leave them there you run a larger risk of having damaged traces/pads.

Re: PC-Engine Duo No video mid cap replacement?

Posted: Mon Jan 09, 2017 6:40 am
by that1crzywhtguy
So bit of an update here. I continued replacing the caps for a while, and while not totally done, have finished about 75%. This has been really bugging me as it doesn't seem like this problem should be caused/fixed by caps. Most of the caps I replaced even tested okay, and it's so weird to go from video working to just blank video.

The other thing I thought to do as a testing thing was to install the RGB chip I ordered from Voultar, and see if I could get RGB video out. I mean, who cares about composite anyway, right? :D

Well, after an install of that, I get the same deal. No video. I'm suspecting this has something to do with the fact that this system doesn't seem to be sending out composite video so I'm getting no signal for sync? Or maybe something else.

As always, appreciate the help in advance.

Re: PC-Engine Duo No video mid cap replacement?

Posted: Mon Jan 09, 2017 4:57 pm
by marurun
You're in well over my head at this point. Sorry. : (

Re: [Solved] PC-Engine Duo No video mid cap replacement?

Posted: Mon Jan 09, 2017 8:00 pm
by that1crzywhtguy
Somebody tipped me off on another forum that "the problem is the traces for the 470uf capacitor which is right by the power switch."

Sure enough, that was it. I broke the trace near that point. After repairing, we have video!

Re: [Solved] PC-Engine Duo No video mid cap replacement?

Posted: Mon Jan 09, 2017 10:36 pm
by marurun
I am really glad you found it. I hate to see a PC Engine system retired before its time.