Sony projector VPL-CX76, Symptom; No secondary supplies, although somehow strangely a little voltage can be measured on one of the opto-couplers (secondary side). Unit comes to me with these conditions, i heat the electrolytic caps in the IC's near periphery (10uF, + two 47uFs) and the ic jumps to life. I replace the 3 caps and send the unit back. Unit comes back in two weeks with the same fault. However this time no amount of heating will kick start the ps. After a lot of investigation and confirmations i replace the MCZ3-001UB and the set works fine. I'd like to archive the state of the dead MCZ3001UB for the benefit of techies. 10V observed at the centre rail between mosfets. Vs (22) of the high gate drive doesn't lift to 160V. Kicking action observed at pin 2 (F/B) coming from one opto shuttling between 2.5 to 3.5 volts.
5V observed at pin 1 (Vsense). OCP (16) = 0V Ct (3) = 0V Rt (5) = 0V 10 V observed at pins 15(Vc1) and 17(Vc2) Should your dead ps display the same symptoms it's safe to make the investment on the pricey MCZ3001UB. Thank you shendengen for not providing datasheet and specs. So professional of you. Jango2- posted
13 years ago