Author Topic: Did I break my duo?  (Read 363 times)

that1crzywhtguy

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Did I break my duo?
« on: January 10, 2017, 05:59:58 AM »
I must admit,  I'm feeling pretty ashamed. Been working on my PC-Engine Duo...I just fixed the dang thing yesterday with a video issue, and now I think I've really gone and mucked things up. As I was proceeding with an RGB mod, I plugged it in to test. I noticed a spark coming off of where I grounded both my obey region chip and the 6280 to the case. I knew this wasn't good, and immediately disconnected. I have no clue what I did to cause this issue, but would seem there is a short somewhere. I took off the RGB chip and checked all over the place for solder blobs or a broken trace or anything burned looking. I see no problems with my visual inspection, but beyond that I'm not sure what to check for. I'm no electronics expert, and mostly just follow instructions pretty well.

Did I totally fry it? I sure hope not. If anybody knows what to check that would be great, and if not, I would wonder about a good repair service so this thing doesn't end up in a trash bin while my heart breaks.

Thanks in advance!

Keith Courage

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Re: Did I break my duo?
« Reply #1 on: January 10, 2017, 07:36:08 AM »
what happens when you try to turn it on? Absolutely nothing?

Is the fuse good? 7805 Voltage regulators good?

that1crzywhtguy

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Re: Did I break my duo?
« Reply #2 on: January 10, 2017, 07:41:04 AM »
what happens when you try to turn it on? Absolutely nothing?

Is the fuse good? 7805 Voltage regulators good?

I tried switching it on for a super short moment and got no video and just a building humm through the speakers. The fuse is fine. As for the regulators, I'm leery of leaving the console on long enough to test em. If I use my multimeter to test continuity between ground and the 5v cart pin (or the 5v point I was using for the RGB amp) I detect a short (only 2.2ohm).

Desh

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Re: Did I break my duo?
« Reply #3 on: January 11, 2017, 12:39:08 AM »
I would start with disconnecting your ground and check for the short.  If the short goes away at least you've narrowed it down to a bridged or incorrect connection with the mod.  I'm sure you've already double checked but triple check you have the correct connections on the mod.  I would also start checked pin to pin of any IC you soldered to.  There could be a bridged connection underneath somewhere you can't see.

that1crzywhtguy

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Re: Did I break my duo?
« Reply #4 on: January 11, 2017, 04:08:08 AM »
I would start with disconnecting your ground and check for the short.  If the short goes away at least you've narrowed it down to a bridged or incorrect connection with the mod.  I'm sure you've already double checked but triple check you have the correct connections on the mod.  I would also start checked pin to pin of any IC you soldered to.  There could be a bridged connection underneath somewhere you can't see.

I did try disconnecting the ground from the mod already, and still the short. I also tried checking the IC pins for a bridge, but nothing there either.

thesteve

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Re: Did I break my duo?
« Reply #5 on: January 11, 2017, 04:26:15 AM »
fun, ive had caps chips and solder cause that, good luck

that1crzywhtguy

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Re: Did I break my duo?
« Reply #6 on: January 11, 2017, 04:37:39 AM »
fun, ive had caps chips and solder cause that, good luck

Thanks. I may have to send this off to repair, and it might be toast anyway. -_-