HELP! My T&F. My Baby!!!

Fly

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It started with occasional resets and freeze ups. Now my T&F and HS boards come up with the letters and junk sprites. These boards work in my Jamma cab though. So I think I can rule out any problem with them.

Funny thing is that I have a bootleg T&F board and it works. Minus 99% of the volume. I can barely hear it. But it plays.

I've checked voltages at the PS and they seem fine. Though I may be doing it all wrong. I'm a total noob.

Any Ideas on where to check next?

Or even better for me, anyone close by and willing to help? I'll throw money at ya'.

Please help. My baby's sick.

Hec
 
If the voltages check OK on the BOARD, not the power supply, then you might have some failing caps in the power supply that is putting ripple on the power lines. This will cause some boards to go bonkers.

Also, the reason I say on the BOARD is that you'll have some voltage drop thanks to the resistance of the wiring and the edge connectors in the cab. Check for +5v on the board itself and adjust the power supply levels to get it set right. Set it for between +5 and +5.2 volts. Some boards need a little more than 5.0 volts to work.

RJ
 
on the board that you can hardly hear, try replacing the electrolytic capacitor in the audio circuit.


I'm not too concerned with this board. I'm more interested in getting my others to work in the cab. But if someone could point out where this is I'll give it a shot. Remeber, this board is a bootleg and has things in different places.


Only thing I've noticed that is different on the game is the sun burst image on the background on the high jump event. I think it's like this on the wall " High * Jump ".

The board also says SUN on one of the edges.


And as for checking voltages ON the board, I'm clueless. I've looked through the forums to try and figure it out but it's never in pictures so I have no idea what anyone is talking about.


Thanks for the help so far and thaks in advance to anyone else willing to join in.

Hec
 
i tired looking in the manual for the schematics but they werent much help. you can follow the traces from the connector to see where they go and to where the audio circuit/section is. usually its near the connector, you can probably see the amp and the capacitor...

when checking voltages on the board, you put the black lead on the ground on the connector and set your meter for DC volts and put the red lead on where the +5 volts finger/trace coming off the connector. you might have to manipulate your black/red leads so you can access the two rails, the ground rail and the +5 volt rail or even the +12 v audio circuit rail. dont put your ground lead on earth ground as thats a different ground in respect to logic ground. it might work but it might give you screwy readings.
you can check BEFORE the connector and AFTER the connector and that will tell you a lot about the state of the connector pins there inside the connector...

so if you have +12 volts after the connector, on the board, then you can start to trace and see where it might stop with no output and thats where your problem is. if you have +12v before the connector and only 6v after the connector, then you know the pin inside the connector has a problem/weak and needs to be replaced.
 
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I had a little time to check things out yesterday and I got a +5.10 when I disconnected the board and checked at the pins in the harness. It was +5.09 at the PS. But when I connected the game again and checked right at the trace comming off the connector I only get +3.94. Problem is, I dont know if I'm doing it right or wrong. You mentioned some stuff about the ground and I'm not sure I got it right, so I tried both red and black on the leads on the board.

Also, is it normal for the harness to get warm in just a couple of minutes? It gets warm right around the +5.

Once again, thanks for your help.
 
Your harness shouldn't really get warm. If the +5 area is heating up then you likely have a problem with the connection at that area. Corrosion or weak connections can create a high resistance area and this area will heat up as you described. I'd check out the pins (with the power off) and see if there are any obvious problems such as a loose crimp or cracked solder in the harness.
 
ok, I cleaned my connector on the harness and got it to read +4.65 on the board. The game ran for a few minutes and froze up. I turned up the PS to +5.2 from +5.09 and got +4.76 on the board. The games run fine now.

Only problem now is that it's still getting warm. Well that and I'm still losing some voltage. What do you guys use to pull the pins in the harness to check things out? How fragile are they. I dont wanna break them.

And a real big thanks to all so far.

Hec
 
If you measure the +5 rail at the power supply and then at the edge connector on the harness and you see a drop in the +5 there's your issue.

Sorry I don;t understand what exactly is getting warm/hot?
 
i use the leg from a transistor to unlock the pin inside the connector and pull on the wire.

add a new ground wire from the ground rail on the game board to the power supply.

the game wants 5.1 ish to run correctly but dont go too high as you can damage chips.

sure sounds like those pins inside the connector are weak and need replacing.
the plastic connector itself is fine just the pins are bad.
 
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