The plot thickens....
The pot at R8 does register resistance change when tested with the DMM, but turning it does not affect any voltages on the AR or on the vector board at all - they remain constant and at the 6.98V.
I tested the bottle cap and it appears fine at this time but I'll replace...
Test results at the test points on the vector board are:
12V is 12.1V
5V is 6.98V
X is 1.073VDC and 1.617VAC
Y is -0.89VDC and 1.766VAC
All done in test mode. Looks like we're on the right path...!
Amazing amount of advice, thank you. No, I have not tested the game board voltage - this is why I was starting to question the voltage source for the deflection board. It's a Star Wars upright.
Thanks all for the suggestions and replies. Thai board is a mystery for sure. It may not even be the board that's the problem, but more like the end result of a problem coming from somewhere else besides the deflection board.
Sure did! I noticed the leg positions were backwards on the schematic vs the replacements and did reverse install them. No idea why the board keeps blowing. When it does, I go through everything once again to replace all the components that failed, not just the ones that smoked.
Bought locally through an electronics shop. No concerns but yes, I did order BU406Ds from eBay and as you mentioned, they were mislabeled who knows what!
I'm at a loss.
The deflection board has been rebuilt with new caps, all new transistors and voltage regulators, upgraded diodes and no modifications.
The bottle caps are substituted with 15003G and 15004G which are compatible upgrades.
The U07s and U57s are now ZTC653s and ZTX753s, again...
Looking for a PCB cage, marquee wooden frame and if possible, a replacement front panel for the coin box area - mine has a gas pedal that was cut in to it at one time. Needs to be shipped to Vancouver BC or Blaine WA.
Pac Man died - audio went mid game and then came back. Next day, playing blind - nothing on the screen but can hear the game.
Grabbed one of two spare G07 boards and it had a mod done for some reason. Grabbed the second one and same thing as well.
Anyone know the purpose of these "updates"...
I picked up this project and hoping to get it back to what it should be. It's had a hard life, but the cabinet is in great shape (aside from where the gas pedal was scabbed in!) Looking for a monitor (or the parts needed) to get this Star Wars upright back up and running. Was converted at one...