I had some oomph to pick up working on my Asteroids setup for a future project. My Power Brick didn't have the 30-0-30 AC required to power the monitor so I went down the route of adding and external transformer to provide the correct voltage. The existing AC supply from the Atari Power Brick was used to power the new transformer, the output from the new transformer is then routed onto the existing cables to the monitor connector.
After that it was a case of powering up the monitor. I had to confirm the pinouts on the deflection board as the monitor is a G05 but the deflection board was a W&G V2000. The connector is keyed in a different place so I compared both sets of schematics and did the following. In the loom that plugs into the P500 connector, remove the purple cable from pin 4, sleve it up so it's insulated, it is not required, remove the 'keyed link' from pin 5 and place into the position at pin 4. The V2000 deflection will now happily work in the G05 chassis.
After completing this, I was only getting a bright dot in the centre of the display. I checked the voltages on the connectors and they all seemed good. Taking the deflection board out I noticed the two high wattage resistors at R100 & R101 looked melted/burnt/warped. measuring these with a meter they appeared open circuit, I removed them from the board and sure enough the were not giving a reading. The Vector FAQ talking of these causing problems, I temporarily replaced the resistors with some thick gauge wire, when powered up I could hear vector chatter and after a few moments the asteroids test pattern appeared on screen, after tweaking the size adjustments on the game pcb everything was looking sweet!
Next up I will be shotgunning the Deflection and HV board's to hopefully reduce downtime in the future.
