General power question

If you can rewire a cab and blow things up, you can learn to replace an LM324. It's not hard. All you need is an iron and a $15 manual solder sucker.

If you're in this hobby, desoldering and replacing chips is something you should know.
I'm guessing not.
 
all of this

with the dozens of threads I've helped you with over the years I'm kind of baffled you accomplished anything without soldering lol


I built my first supergun without one solder joint.

But I quickly learned to solder after that.
 
I built my first supergun without one solder joint.

But I quickly learned to solder after that.
I never thought I'd see the day you post in repair :ROFLMAO:

and yeah my supergun was built out of a HotRod SE with a JAMMA harness from an NBA Jam I bought years ago. I still have the keyboard controller gimmick and should have the PS/2 cable also somewhere. no solder, just crimping a bunch of quick disconnects
 
Upon arrival I got zero sounds from your boardstack.

Upon initial review your heatsink on bottom board was space shuttling.

Like burned my fucking fingers hot. Replaced 7815 no change.

Replaced TDA2002 and now I have all audio back. It's 100% correct but low.

Will take a look at other areas this weekend and report back. Wondering if shorted TDA2002 cooked something else or if the amp you tried wiring in backfed and lit her up.

@DogP any thoughts?

Edit - pot is also good 120ohm up to 4.75k
 
Last edited:
And just to be clear, at max volume on bench, it is crystal clear, no static and is at a usable volume, just not as loud as I think my others are. I'll compare to another working stack this weekend.
 
Replaced TDA2002 and now I have all audio back. It's 100% correct but low.
Since you have other boardsets there, IMO I'd swap top boards and see whether the problem is on the top or bottom board. The top board does all the audio generation, but the bottom board does the final stage amplification to drive the speaker. Low audio could be a component around the TDA2002 on the bottom board, or an LM324 (or component around it) on the top board.

If all audio sounds balanced, but weak, I'd suspect it's either around U83 on the top board, or U122 on the bottom board. I don't have a board nearby to check, but I don't think the jumper wire between boards goes through any LM324s on the bottom board. If certain channels are weaker (easily checked in test mode), then it's almost certainly on the top board.

DogP
 
Since you have other boardsets there, IMO I'd swap top boards and see whether the problem is on the top or bottom board. The top board does all the audio generation, but the bottom board does the final stage amplification to drive the speaker. Low audio could be a component around the TDA2002 on the bottom board, or an LM324 (or component around it) on the top board.

If all audio sounds balanced, but weak, I'd suspect it's either around U83 on the top board, or U122 on the bottom board. I don't have a board nearby to check, but I don't think the jumper wire between boards goes through any LM324s on the bottom board. If certain channels are weaker (easily checked in test mode), then it's almost certainly on the top board.

DogP
crystal clear, all even imo.
Will play musical chairs this weekend and see WTF.
 
Since you have other boardsets there, IMO I'd swap top boards and see whether the problem is on the top or bottom board. The top board does all the audio generation, but the bottom board does the final stage amplification to drive the speaker. Low audio could be a component around the TDA2002 on the bottom board, or an LM324 (or component around it) on the top board.

If all audio sounds balanced, but weak, I'd suspect it's either around U83 on the top board, or U122 on the bottom board. I don't have a board nearby to check, but I don't think the jumper wire between boards goes through any LM324s on the bottom board. If certain channels are weaker (easily checked in test mode), then it's almost certainly on the top board.

DogP
Musical chairs says problem is on bottom board. Swapped onto known Good bottom, loud as hell. I'll keep poking….
 
Last edited:
Musical chairs says problem is on bottom board. Swapped onto know. Good bottom, loud as hell. Let keep poking….
R56 failed open.
Replaced. Sound is loud and clear.

Will leave on bench for a bit running audio tests but should be on its way back to @sirgubster9 before your family party.

drop whatever donation you see fit towards local foodbank or similar charity and enjoy.
I'll cover return shipping also so juice up donation a bit if it suits your budget.
 
Last edited:
So many generous people. The christmas spirit is truly here my friends. Thank you!
So in the Christmas spirit, GIVE BACK and stop resisting everyone's advice on here... LEARN TO SOLDER. It's not that hard. (Heat the joint with the tip with as much contact as possible on both the board and the part.... put the solder to the joint opposite the tip and it will flow.) There are plenty of tutorials online.(can anyone site a reference for proper technique from any fellow members YT vids, etc)

All it takes is practice. Use the web to find some soldering practice kits with through hole components... not surface mount... and practice. There are plenty of companies that have inexpensive kits for various widgets. Get a couple and assemble them... then practice desoldering. Low cost kits can help developers and hone your skills before jumping into arcade PCBs.

If you are going to be in the hobby for any length of time, YOU WILL NEED TO LEARN TO SOLDER. It's like driving a car... you can't drive a car if you don't learn how to insert the key and twist it.(I know, new cars have dumbed it down to having the fob close and pushing a button... but unless you learn to push the brake pedal down first, it still won't start 🙂)

It is almost painful and bewildering to see you give every excuse in the book to avoid soldering after countless members have told you it is necessary, and it really is a simple process... and practice will make you proficient in a short amount of time.

There, I have removed all your excuses... now you must learn! It's not hard. Really.

Of course there are other hobbies like collecting Hello Kitty stuff or Pokémon cards or baking cookies that don't require the skill of soldering... just sayin'

Dylan
 
Back
Top Bottom