Please help! Broken circuit board

[That80sGuy]

Yup. Just double check your schematics.

 

Good Luck!

[AlanD]

Very weird wiring job on the amp they did. Looks like they had an old Williams pinball or Joust/Robotron series of sound board and just wired it in. I have to clean out my shed today and may come across a Universal amp. If I do I'll let you know and we can work a swap/sale if you like.

Alan

[Dav]

I can attest to the wait 5 minutes and discharge it again. The second zap wasn't enough to hurt me but it was enough to make me lose control of my arm. The one that was carying the tube. Fortunately I caught it with my other arm.

 

 

You can make an amp for mr do, etc for a couple of bucks from an lm380 and some junk you probably already have. 2 caps and a resister iirc. Or you can cut the amp section out of another pcb. I've heard SF2 is good for this, so sf2 pcb's are good for more than just blank roms.

[bjk7382]

I can attest to the wait 5 minutes and discharge it again.   The second zap wasn't enough to hurt me but it was enough to make me lose control of my arm.  The one that was carying the tube.  Fortunately I caught it with my other arm.

When I got shocked it was 2 right in a short amount of time and I wasn't carrying the tube luckily. I was using a small pair of insulated needlenose pliers and my finger got too close to the metal of the pliers. And then after I got hit the first time I moved and got another small one. It was enought to feel it after it happened, but I don't think it was that serious (but then I have seen someone get smacked by 440 and get knocked 3 feet back).

You can make an amp for mr do, etc  

Maybe YOU can make an amp , but it is beyond my electrical knowlege to make any kind of circuit, no matter how simple. (unless there are step by step instructions somewhere )

[Dav]

It is pretty easy. Here's a quote from the conversion faq for you. There's a lot more stuff about it if you google rec.games.video.arcade.collecting as it's a common solution, not just for external amp games but games that use bizarre voltages for their amps.

 

- Unamplified output is a little tricker; it needs to be

amplified before you'll hear anything. On an original game

with unamplified sound (including most older Atari games,

Universal's "Mr. Do" series of games, and many older Midway

games), there was an audio amplification board somewhere in

the cabinet that served this purpose. Odds are that you

didn't get it when you got the game board, though, so you

might have to build your own instead.

- If you're going to try and run both types of audio in the same

cabinet, you'll have to pay special attention to this issue,

usually by putting an amplifier between the board and the

speakers, activated when required by an external switch.

- You can make a quick-n-dirty audio amplifier with an LM380

op-amp as follows: Put unamplified audio on one side of a

10K volume pot and the other side of the pot to GND. The

center tap of the pot is connected to pin 2 (the input) of

the LM380. Pins 7 and 3 of the LM380 go to GND. Connect

pin 14 of the LM380 to +12V DC. (Don't forget an 0.1 uF

decoupling capacitor between +12V DC and GND). Pin 8 of the

LM380 (the output) gets a 2.7 ohm resistor in series with

an 0.1uf cap to GND to prevent the chip from oscillating.

Finally, stick the positive end of a 250 uF electrolytic

capacitor to pin 8; the negative end of this capacitor goes

to one of the speaker leads. The other speaker lead goes to

GND. Power it up, and away you go!

[bjk7382]

That actually doesn't sound too hard, but I already have that other amp on the way, so I should be okay And I don't have any of those parts anyway.

 

Also @ AlanD - if you find an original universal sound amp, I would like to buy it, because original equpment is always better

[bjk7382]

Okay, I have the amp I ordered installed, and I am starting to think that it isn't as good as an original amp.

 

I figured the sound wouldn't be as good as the original, but this sounds really tinny, and there is no bass. Is this how it is supposed to sound because it is such a small and inexpensive amp? The sound isn't horrible, but it deffinitely doesn't sound as good as my Do Run Run, which has a universal amp in it.