I have recently bought a GE901 projector (NEC PG9) in perfect shape with 900 hours only. This machine was probably unused for years. I turned it on a few times for some hours with no problem. Then a few days ago I left it on five hours projecting a (very good) image again with no problem (at ANY brightness and contrast position). Three hours later turned on and it went off in a few seconds. Turned on again it worked (perfect image) twenty seconds then off... Now it always stays on one second then off for five seconds and loops this way infinitely. No codes on back display.
I have service manual so I tested power supply outside projector as they say. Putted a 3.6 Kohm 10W resistor on the 180V output to avoid protection cut off and applied 1.5V DC on the specified connector and I discovered power supply itself to have the same behaviour of the proj!
On for a second only. Interesting think is that I get ALL correct voltages while PS is on (used a peak hold function tester). Is this PS behaviour in stand alone mode correct?
When proj is on two red leds on DEF board are on, but I’m not sure this is a real problem because PG9 goes immediately off. Anyway I checked Horizontal output transitor on DEF board and it’s not shorted. Thank you.
I have service manual so I tested power supply outside projector as they say. Putted a 3.6 Kohm 10W resistor on the 180V output to avoid protection cut off and applied 1.5V DC on the specified connector and I discovered power supply itself to have the same behaviour of the proj!
On for a second only. Interesting think is that I get ALL correct voltages while PS is on (used a peak hold function tester). Is this PS behaviour in stand alone mode correct?
When proj is on two red leds on DEF board are on, but I’m not sure this is a real problem because PG9 goes immediately off. Anyway I checked Horizontal output transitor on DEF board and it’s not shorted. Thank you.