Tron MCR Suitcase Rebuild

This page is here to document my recent rebuilding of the MCR power suitcase in my Tron machine. I had previously rebuilt the MCR power supply board, but recently started having power issues on the game. The game would freeze, reboot, get stuck on the crosshatch pattern screen, report bad ram at B3. I measured the +5V and it was at 4.9V. I turned it up to 5.1V and the game seemed to work fine. Decided to go ahead and rebuild the power supply and remove the hacked in switcher that was there when I bought it. It looks like the switcher was just there to add juice to the +5V line, the original suitcase was still hooked up but seemed to be flaking out. I also wanted to replace the electrolytic caps on the game pcb's.

Parts List For Suitcase Power Supply:

• • Midway (MCR) Capacitor 55,000uf 25v - Bob Roberts $15.00

  • Midway (MCR) Capacitor 100,000uf 16v - Bob Roberts $20.00

  • Fuses - 6A 250v fast blow - Bob Roberts $3.00 for a 5 pack

  • Fuses - 10A 250v fast blow - Bob Roberts $3.00 for a 5 pack

  • Fuses - 2A 250v slow blow - Bob Roberts $3.00 for a 5 pack

  • Fuses - 3A 250v slow blow - Bob Roberts $3.00 for a 5 pack

  • Fuses - 1.5A 250v slow blow - Bob Roberts $3.00 for a 5 pack

  • Oil Cap 3.5uf 440VAC (listed as a motor start capacitor) - $1.50 from http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product_Code=TM90CAP1173 (min order $15.00 so buy some other parts you need while you're there). They do sell PCB trace repair pens, so I picked up one of those for $24.50.

  • 4x Rectifier Diodes 50v 12A 1N1199A - from Mouser part #905-1N1199A $2.80 ea (6/21/12) http://www.mouser.com/ProductDetail/GeneSiC-Semiconductor/1N1199A/?qs=UW%252b%252bp%2fVkpn%2fCje0X1UmmJr0eBBtvYLb%2fiDh8oEAmCZY%3d

Parts List For Game PCB capacitors:

• • 10pk 470uf 25v axial caps - Bob Roberts $5.50. You only need 8 of these (4 on the cpu board, 4 on the sound board).

  • 10pk 100uf 25v axial caps - Bob Roberts $3.50. You only need 2 of these for the video pcb, I ordered extras for the parts box.

Here's the bottom of the cab before starting the work. A switcher was installed at some point, assuming the original power supply was having issues.

The +5v lines from the switcher were soldered onto the legs of one of the capacitors on the main game PCB

I removed the swticher and replaced the electrolytic capacitors on the 3 game boards. 4-470uf 16v replaced with 470uf 25v on the CPU PCB:

This is the video pcb, I replaced the 2 - 100uf 25v caps with the same values.

This is the super sound i/o PCB, I replaced the 4 - 470uf 16v caps with 470uf 25v caps.

Here is the original suitcase still installed in the cab. The plan is to 'bulletproof' this thing by replacing all the parts with new.

Here's the suitcase after pulling it from the cab. The big caps, diodes and fuses will be replaced.

I tested the 4 diodes and they tested fine. I went ahead and replaced them anyway for preventive maintenance. They look like little spark plugs.

Top view:

View from bottom. These are 50v 12A rectifier diodes available from Mouser (see top of page for link)

And here are the new ones installed with the wires soldered to them. Also replaced the 2 fuses (6A & 10A fast blow).

Here are the old filter caps. Notice the + terminals are marked with red. I used a pen to write + - to make it more visible.

Here are the old and new caps for a visual comparison. Also made sure I had the polarity correct prior to hooking up the wires.

The old caps were connected with spade connectors, but the new ones have screw in terminals. I picked up some 10-32x1/2 screws to use on the new caps.

The new screws were a little bit too long, so I used a nut at the base to make it work.

Here are the new caps connected up.

You could use rubber boots to cover the terminals, but I just made sure they didn't contact anything else in the suitcase.

And here's the final suitcase assembly with the new parts

Installed into the cabinet

The game fired up and worked great at this point, but one last thing I wanted to do was replace the oil cap

Here's the new one. See link at the top of the page for parts source info

Here's what the bottom of the cab looks like now