Defender's got me down (again)

for +5, 2N6057 (large heatsink) for +12, 2N3055 (small heatsink). try reseating the transistors. if your +12 doesn't return, I would concentrate on the bridge rectifier, it's not melted is it?

Bridge rectifier looks fine.

I'm going to run through all the test points from the schematic tonight.

I have bought and fixed 4 other cabinets while this Defender has been dead. I'm feeling like it's bit of a war at this point.
 
Voltages are back in the ballpark, but almost exactly where they were before I redid everything. I'm going to re-do all the connectors and see if that boosts the 4.95 up.

Also, who sells the ribbons cables?

Again, thanks for all the help guys.
 
Voltages are back in the ballpark, but almost exactly where they were before I redid everything. I'm going to re-do all the connectors and see if that boosts the 4.95 up.

Also, who sells the ribbons cables?

Again, thanks for all the help guys.

I get them from Quarter Arcade. https://quarterarcade.com/williams-rom-and-interface-cables-new-10472

I don't remember the exact jumper configuration, but there's a resistor you can remove that will change the outgoing voltage from about 4.95 to 5.10V. if you're running factory 4116 ram still, your game should operate fine. it's not really until you dip below 4.75 that you should have problems, but there's enough variations in this hardware that your mileage totally may vary. there's a block of resistors that connect to the voltage regulator ICs, I think I had to modify them on the Joust and Robotron at work, but the games are buried now. I'll see if I can find you information. I'm certain that they're jumpered the exact same despite being 2 "different" power supplies -- they're largely identical despite being arranged different.
 
you could add a trimmer pot in place of R2 on D8359 power supply (10K) and that way you can adjust the +5 to what you want. i include that in my rebuild kits now that i have tested it, but you can buy that separate. (if someone is using the D8784 then its R25 to put the pot). i have the wiper on the pot already modified so you just drop the pot in the pcb and its a great fit.
 
you could add a trimmer pot in place of R2 on D8359 power supply (10K) and that way you can adjust the +5 to what you want. i include that in my rebuild kits now that i have tested it, but you can buy that separate. (if someone is using the D8784 then its R25 to put the pot). i have the wiper on the pot already modified so you just drop the pot in the pcb and its a great fit.

I just did your full boogie rebuild kit.
Can I get the pot with instructions? (I don't mean for free)

Thanks
 
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I just did your full boogie rebuild kit.
Can I get the pot with instructions? (I don't mean for free)

Thanks

if you have anything to order i would throw the pot/instructions for free with your order otherwise pm me.
 
I did adjustment pots on all the Defender power supplies I've come across. the only thing that's dangerous about this is the range will go in excess of 6 volts. so if I can find a way to do the hardwired method with just resistors I'd much rather like to go that route. I'll need to dig up the schematics on these to find the factory values; many people do their own mods pulling or replacing resistors.
 
Is this the pot?

that pot won't work. i have one that is intentionally not on my site yet because i want to do a video on the mod and the pot so its much easier for people before i officially release it.
 
that pot won't work. i have one that is intentionally not on my site yet because i want to do a video on the mod and the pot so its much easier for people before i officially release it.

OK, just bought a few things from your site. Here's the paypal receipt 4DE68048XJ771353W
It was for $12.03.

Let me know if I owe you anything for the pot.

Thanks again for the help!
 
So I added the pot and adjusted the 4.95 up to 5.01. Worked great.
But it didn't change what was happening with the game. Same weird partial screen garbage.
Also this (see pic) got instantly super hot. Like melt plastic hot inside a minute.

Any ideas?
 

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