MCR Power Supply Rebuild Success

Torin

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Donor 2013
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Well, I rebuilt my newly acquired Tron PS with Bob's kit and it wasn't the easiest thing I've done. When I got the Tron, the fuse on the PS was blown and it had quite a bit of battery acid damage. Replaced the fuse and my 5V voltage was stuck too high at 5.65 at the pcb. At the PS, it was really high over 7. Well, I ordered the kit from Bob because the molex connectors and other things were all green from battery acid.

I had a hell of a time replacing those molex connectors that were coated in green acid. Damn those things were hard to desolder and remove! Finally did it and replaced most of the other parts in the kit. Lifted a couple a traces that I had to repair but now have a steady 5V at the pcb. The PS is still around 5.4 at the capacitor but I think that should be ok.

Game is running great now. I thought I'd share this for anyone with voltages that might be too high or low. The kit from Bob is well worth it and made a big difference.

Any tips on how to desolder those molex connectors from the PS?
 
YOU need to have some very small/thin needle nose plyers or hemostats to clamp onto on of the pins, flip the board upside down and hit it with the soldering iron, as you pull on the pin with the other hand. NOt the easiest thing, but you want to pull 1 pin at a time not try to get that whole 15 pin molex pulled at once. Like to damage the board pulling up that big piece at one time.
 
YOU need to have some very small/thin needle nose plyers or hemostats to clamp onto on of the pins, flip the board upside down and hit it with the soldering iron, as you pull on the pin with the other hand. NOt the easiest thing, but you want to pull 1 pin at a time not try to get that whole 15 pin molex pulled at once. Like to damage the board pulling up that big piece at one time.

Cool, I will do that next time. Luckily, I only had to replace the three and twelve pin molex connectors. The twelve pin was tough and that is where I lifted the trace. I need to get some thinner plyers.
 
Great work Torin. Your hi-res pics also helped me tremendously in getting my TRON back to life again. Thank you.
 
YOU need to have some very small/thin needle nose plyers or hemostats to clamp onto on of the pins, flip the board upside down and hit it with the soldering iron, as you pull on the pin with the other hand. NOt the easiest thing, but you want to pull 1 pin at a time not try to get that whole 15 pin molex pulled at once. Like to damage the board pulling up that big piece at one time.

After adding fresh solder to each pin with my soldering iron, I use a soldering gun and apply the tip to the pin and not the PCB - it heats the pin and solder quickly and I can remove the pin. It takes a little practice but as soon as the pin is loose from the heat melting the solder and softening the plastic of the header, you need to pull the pin out quickly before it gets a chance to cool. Clamping a hemostat can act like a heat sink so clamp it as far away from the board as possible or you will be trying to heat the pin and the hemostat. I use a pair of needle nose pliers as I feel I have more control. I use this technique to remove the 24 pin headers on Battlezone boards.

Bill
 
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