Chassis Model: P538 (
Schematic)
This unit was purchased from a warehouse where it's sat for years, so its quite dirty. I am rebuilding the frame which has some rust, and the wooden base is swollen and damaged. This monitor was set up for use with laser disk games. I doubt it was a dragons lair; I expect it was maybe used with a game like Mad Dog McCree. It has the P612 riser board. I have no use for the NTSC decoding function of this monitor, and it seems the board labeled P612 has what looks like a second horizontal width coil. It has two connectors that go to the NTSC decoder board, so perhaps it has something to do with the NTSC functionality?
My questions are:
What is the function of the P612 board?
More importantly, can I remove this without issue? Will I be able to use the board as a normal arcade monitor chassis, or do I need to do some further modifications to undo the added ntsc functionality? There are some bodge wires that seem related to this purpose going to the connector for the P612 board on the chassis (pictured), and there is a secondary connector/harness soldered to R67 and R83 that goes to a connector on the P612 board. It appears to tap into some part of the deflection circuitry.
There is also a secondary board that appears to be connected to the flyback, a P741, which is also not listed on the schematic. Does anyone know the function of this board?
Beyond this, so far I have not seen anything visually that is damaged save a broken contrast trimmer pot (pictured).
I am comfortable with electronics, but have limited experience in analog circuitry. I have ordered a cap kit, given it was sitting in a non-environmentally controlled warehouse for who knows how long, but I am curious what people think about replacing any other parts as a matter of course? I think I should not replace the HOT or Flyback unless they have failed, but do intend to purchase some as potential repairs at a later date, but there may be some other components that should be replaced that I am unaware of. They say an ounce of prevention is worth a pound of cure, so if there is something I should just replace, or some maintenance that should be performed, I would be grateful for the advice.
I plan to do a repair log and share when finished, and thanks for any assistance anyone can provide.