Toki bootleg woes part 2 - No sound!

[daeds]

Hey there!
Well the board arrived in pretty bad shape, second board connector broken, oh well, that was fixed but now it completely has no sound.. and it had sound before the dude sent it,
The caps seem OK and the amp gets hot, no noise is made when I touch the pot, amp or opamp though,
Any ideas?

The amp gets very very hot to the touch, and it's kinda... black or charred?
I've tried a PSU with -5v and nada...
Looking forward for your help!

 

[djsheep]

You should have just continued on with your first thread: https://www.arcade-projects.com/threads/toki-board-with-cutting-audio.34940/

No need for another when so much information related to this issue has already been dealt.

Was going to say -5v as @AlxUnderBase already suggested in your other thread, but you’ve tried that.

Is the bootleg even JAMMA? Also what is that Supergun? Have you confirmed the Supergun works and outputs audio on a working board?

 

[daeds]

You should have just continued on with your first thread: https://www.arcade-projects.com/threads/toki-board-with-cutting-audio.34940/

No need for another when so much information related to this issue has already been dealt.

Was going to say -5v as @AlxUnderBase already suggested in your other thread, but you’ve tried that.

Is the bootleg even JAMMA? Also what is that Supergun? Have you confirmed the Supergun works and outputs audio on a working board?

True, sorry about that!
Yeah, it's JAMMA and it was working before shipping (says the seller...) The SG is indeed working well, I've tested it with my boards, I'm a bit lost here, I've checked the soldering and retouched some soldering on the sound part that seemed sketchy but it's the same.
I see that it seems some caps are missing on the bottom part of the circuitry though, could it be it? I have them on order already.
Thank you.

 

[djsheep]

Type in Toki bootleg PCB repair and Toki PCB repair into that magical thing called Google and you’ll see there’s a lot of repair logs that deal with this board with no sound.

Eg. https://www.aussiearcade.com/topic/18123-toki-repair-log/

I suggest reading every single one you can find and the doing a bit of poking around and reporting back if any of the solutions work.

 

[daeds]

Type in Toki bootleg PCB repair and Toki PCB repair into that magical thing called Google and you’ll see there’s a lot of repair logs that deal with this board with no sound.

Eg. https://www.aussiearcade.com/topic/18123-toki-repair-log/

I suggest reading every single one you can find and the doing a bit of poking around and reporting back if any of the solutions work.

I've been actually reading those logs since I got the board, just wanted to ask around if anyone had the same board with the same problem that could lend a faster hand, I'm still missing the oscilloscope and the logic probe, sadly.

 

[djsheep]

Without those tools you won’t be able to do diagnosis. Perhaps you can send it off for repair?

The best you’re going to do is to shotgun it and try replacing components one by one until it works.

Pretty sure that repair log I posted shows at least three others who have fixed their board with common parts or a simple reflow on a crystal. I’d suggest doing that first.

 

[daeds]

Without those tools you won’t be able to do diagnosis. Perhaps you can send it off for repair?

The best you’re going to do is to shotgun it and try replacing components one by one until it works.

Pretty sure that repair log I posted shows at least three others who have fixed their board with common parts or a simple reflow on a crystal. I’d suggest doing that first.

Will do and try to get a better grip of this when I get at least my logic probe. Thank you for your help and patience.

 

[daeds]

My perseverance didn't let me stop for lunch and I actually fixed it by looking at the amp and trying to check for continuity between pin 1 of the amp (output) and the pin 10 of the connector and as soon as I touched the pin 10 the sound works...? I'm in awe right now, can I just pass a bodge wire directly to the connector and we're done?