Qbert questions??

FlashbaxArcade

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ok, just trying to repair my 1st Qbert and a pretty much totally dead one at that(besides a working monitor and hard-wired fan in rear)!

first i replaced with rebuilt power pcb(Riptor)....now all LEDs light up except 5v LED. still dead and guessing because it hasn't got the 5v to drive pcbs! read about the 30v but guessing it goes through other pcb before the power pcb 1st??? no idea where to start on this thing.

does anyone have a troubleshooting guide for a Qbert(site or thread) available?

thanks in advance....
 
also, forgot to mention, already reflowed the header pins on filter pcb(they didn't look good at all but great now) as was suggested in prior threads!
 
Hmmm, check all the fuses on the power brick in the bottom of the cab.

ahh, i did check them as i usually do at 1st and all looked ok from naked eye...meter checked all and one on left at bottom of block was blown! you happen to know value of the left fuse? mine has no reading
 
F4 is a 10A slow blow. It is for the 9V AC that eventually becomes the +5. You probably have a bad bridge rectifier on the power brick.
 
I just bought some 10 amp slo blo fuses.
I think it cost me $4.99 for them. (probably 3-6 in the package cannot remember)
Got them at fry's.
 
Sound board either works or it doesnt. I would suspect the pot behind the coin door.
I have some that will work. Not an exact replacment but they work fine.
Move it a little and see if the sound clears up.
 
Sound board either works or it doesnt. I would suspect the pot behind the coin door.
I have some that will work. Not an exact replacment but they work fine.
Move it a little and see if the sound clears up.

ok thanks....my speaker is in shambles! not even a cone left just inner cone. still might also be a pot but gotta replace this speaker 1st!

thanks for the help
 
Well obviously thats likely your problem but most of the time those volume pots are shot too. Replace that speaker and if your still having troubles PM me if you want to order a volume pot.
 
F4 is a 10A slow blow. It is for the 9V AC that eventually becomes the +5. You probably have a bad bridge rectifier on the power brick.

my F4 10A fuse blew again after a couple weeks of playing(off and on of course).

what would cause this? i would think the bridge rectifier would either be good or bad since they are just diodes, correct?

only thing i could figure would be this fuse holder was very ugly/corroded and the wire was barely hangin on one side! i replaced with a new one and soldered.

wanna nip this in the ass before i have another party!!!
 

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My QB bench rig started blowing that fuse a while back and it ended up being a bad filter cap 50K uf 25v on the brick.
 
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