This printer would power up fine than after 5 min would shut off by itself. If I turned it off for a few min and turned it back on it would come on again for a few min than turn off again. It would stay on for less and less time, until now it will not turn on at all.
Problem seems to be in the power supply itself, switching type. Here is the info off the supply:
DAHA011495 Model#: DPS-85JB Customer#: RH3-2105 AC Input: 100-120 VAC/4.8A, 45 - 65 HZ Output: +5V/5A, +12V/0.7A, +24V/1.5A, 69.4 Watts Date code: 1992-6 Rev A0 Delta Electronics
The HP part number is 33471-69017 which is a RG1-1782.
I checked the caps in the power supply with a Dick Smith ESR meter and found one with a very high ESR, C6 (1uF/50V) and leaky. Changed it and C152 (1000uF/25V) and C302 (2200uF/35V). Also changed IC101 (TL494).
I am back to the original problem. The printer will come on for two min, and then turn itself off. I have to turn it off for a few min before it will turn on again. Never stays on for more than two min. It does not look like a heat problem; I tried cold spray on various parts in the power supply with no luck. I touched up any solder joints in the Power supply that did not look good and checked all diodes and transistors and the FET, all check good with no power on. Unless something is breaking down under load.
Any help would be appricated.
Thanks Tony