It's dead!!! But hopefully I can revive it

FMonk

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Ok, this happened a week or two ago, and I made a page to talk about what actually happened, but I haven't had a chance to post about it till now. My Q*Bert is dead! :( I could really use some help here. I'm pretty sure that it's a power supply problem, but I'm not positive. And due to the nature of the problem, I'd rather not plug everything back together and test it with a multimeter... but see for yourself here:

http://www.angelfire.com/ks2/estonia/arcade/QBERT/help/help.htm

I am pretty bad at reading schematics, so I included a link to the schematics for Q*Bert in that link, because I'm not really sure what it is that the damaged area of the board does (I'm pretty sure that since it's printed "filter board" on the pcb, that it's a power supply filter board) Hopefully you guys can help me out with this one! :crazy:
 
OK... first of all the filter board doesn't do much other than add more connections to fail. It was used to protect other equipment such as televisions and radios, but most everything is shielded better now.

That plug comes from the 9VAC on the transformer, through a 10A fuse (F4), and into a bridge rectifier that changes the 9VAC to 11.5VDC. Check to make sure the F4 fuse isn't blown, check all the diodes int he bridge, and check the filter cap C1 (50,000uF). My guess is the filter cap is shorted.

Replace the pin in the board, if possible. You may just have to hack the pug and solder the wire right to the trace. The problem is the plugs build up resistance over time and causes too much heat.
 
Thanks Greywolf! :) I will look at that later on and see if I can find any of the problems you mentioned... I need my Q*Bert fix! :p
 
Ok, so I think that I 've found the problem... After studying the schematics closely and using Greywolf's help :), I'm pretty sure that the F4 fuse went bad, but was still allowing current to pass through it. All the other components that were between the supply and the filter board looked fine, but F4 had corrosion on one of the ends, the wire connected to that end had heat damage on it (I'm going to cut out the damaged section), and the fuse itself was not broken inside, but it was bent a a strange angle and there was junk inside the fuse. I've updated the above mentioned page so you can see what I'm talking about.

I haven't had time to look for a replacement fuse yet, but I am going to try to get around to fixing at least the other parts that were damaged this weekend.
 
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