Gorf fuse for sound pops (reasons why?)

jot3

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I replaced fuses earlier today (still hoping I got the right ones in there because there isn't labeled)

I replaced the fuse for what I assume is for the sound portion of the game. It immediately pops the fuse but I do hear an initial pop on the speakers as if it wants to work. :)

I don't know how to do anything. This is my first official dedicated cab and I'm a bit overwhelmed. Where do I start????

Oh and tried to re-seat the game boards a few times, but still get a scrambled picture as if the game is running but it's filled with a bunch of bars in front of the game.
 
I replaced fuses earlier today (still hoping I got the right ones in there because there isn't labeled)

I replaced the fuse for what I assume is for the sound portion of the game. It immediately pops the fuse but I do hear an initial pop on the speakers as if it wants to work. :)

I don't know how to do anything. This is my first official dedicated cab and I'm a bit overwhelmed. Where do I start????

Oh and tried to re-seat the game boards a few times, but still get a scrambled picture as if the game is running but it's filled with a bunch of bars in front of the game.

It is probably the sound amp or a transistor is shorted. You can look on the net to find how to test. If you have a meter it is easy enough to do. Make certain that nothing is touching the fuse holder (not a likely this is the prob. but worth a look). Maybe ohm the fuse holder to ground (on each side of the fuse holder) to see which side is mucked up. WITH POWER OFF

This is always a good read since you haven't worked on a game before. I keep the Atari book and the ttl pocket guide handy.

http://forums.arcade-museum.com/showthread.php?t=177192

You really need to make a decision here.

Do you really want to learn to repair these?

Do you want to spend the money for test equipment and chip programmers, not to mention a scope and logic probe? Then you get to where I am at; You need replacement parts. I happen to have a neighbor that sells parts not real far from me.

Enjoy the read. It has lots of info and will answer many basic questions you might have.
 
One of the two TIP31's on the sound pcb are shorted. Also ohm out the resistors as there are a couple that are usually burned.
 
Unplugged Sound AMP and...

Unplugged sound amp and popped in a new fuse into the fuse block that kept going out.

Well...no popped fuse...so I can only assume it's the sound amp. So since I'm clueless on how to use my ohm meter (bought it for something unrelated)....I only use it and just listen to see if it buzzes from each resistor / etc etc.

So everything buzzes from point to point except R4 and CR2.
I'm not sure how to measure the other parts of the board. I just know I hear "buzz" with my ohm meter.

Sorry...I'm an arcade virgin.

-jot3
 
Analog meter

I went to youtube and figured out I'm not testing properly. Soo....I guess I'm still lost.

I guess at this point, I just need to find parts. Where do I find these parts? I've seen people say "the real bob roberts" but i can't find specific parts from my board.
 
I went to youtube and figured out I'm not testing properly. Soo....I guess I'm still lost.

I guess at this point, I just need to find parts. Where do I find these parts? I've seen people say "the real bob roberts" but i can't find specific parts from my board.

If you can't test the basic parts then I would not try to repair that board!

You might put the amp in backwards or burn up a new amp as something else would be wrong.
 
You might put the amp in backwards or burn up a new amp as something else would be wrong.

I agree he'd maybe be better off fixing the board but we don't have to assume he's a complete idiot... If he bought a replacement part one would assume he would look at it, take a photo, put in the new one exactly as the old one--and may even be successful. :)

That said, he's right if you just shotgun the parts you might end up blowing the same part up.

Note: The Real Bob Roberts website is difficult to navigate and largely only contains generic parts... ICs, Transistors, Capacitors, power cords, a ton of misc parts and a few specialty items. I, and many of us, have used him for Atari power supply rebuilds, numerous cap kits, power cables and other misc items. Although he may have some New Old Stock of original generic parts, his site is not a great source for NOS parts--generally speaking. Or at least it hasn't been for me?

You'd be best off searching these forums and looking on eBay for parts. Searching here will lead you to other vendors that we all prefer. (Arcadeshop, QuarterArcade, TwistyWrist, TwistedQuarter, JammaParts.net, etc etc etc etc etc etc) Post in the want ads here for things you need. However, if you don't know what you need you'll likely end up paying a lot for something that you didn't. ;)

The tools I end up using most are:

Multimeter - I have two. One that even tests transistors.
And a cheap logic probe. - http://www.amazon.com/Elenco-Electr...F8&qid=1346969549&sr=8-1&keywords=logic+probe

Even if you don't know how to use either of these if you ask the right questions, I've found that folks here are willing to point you in the right direction or in some cases even work with you on the phone.

Else... Spend money. :)

Welcome to the Arcade collecting community where we spend most of our time wanting, less time acquiring and all the rest of the time repairing and restoring.
 
Unplugged sound amp and popped in a new fuse into the fuse block that kept going out.

Well...no popped fuse...so I can only assume it's the sound amp. So since I'm clueless on how to use my ohm meter (bought it for something unrelated)....I only use it and just listen to see if it buzzes from each resistor / etc etc.

So everything buzzes from point to point except R4 and CR2.
I'm not sure how to measure the other parts of the board. I just know I hear "buzz" with my ohm meter.

Sorry...I'm an arcade virgin.

-jot3

I hope you are doing this with the power off.

In addition to the link in post #2 here is some info on the multi meter and how to use it properly.

http://www.wikihow.com/Use-a-Multimeter
 
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