I have this Delta TDPS-138AF B out of a Avaya phone system here for repair.
Symptom: no output power on any of them rails.
Fuse is good, PFC is working as I have 384VDC laying on the main filter cap, it draws about 4W from AC mains, heat sink on the main section gets warm, but I'll be damned to get anything out from any rail on the secondary. There aren't any shorts on the secondary, diodes check good and the fets check good too. Checked the gate resistors and those check out as well. Also checked the transformers if the little thermal fuse is open, but no dice there either. Now I think is has something to do with the driver card.
There is a driver card soldered into the middle of the PSU. It consists out of a PWM for the booster, op amp, timer and comperators. Complicated thingy!
Anyone has a schematic for this PSU would be greatly appreciated!
Symptom: no output power on any of them rails.
Fuse is good, PFC is working as I have 384VDC laying on the main filter cap, it draws about 4W from AC mains, heat sink on the main section gets warm, but I'll be damned to get anything out from any rail on the secondary. There aren't any shorts on the secondary, diodes check good and the fets check good too. Checked the gate resistors and those check out as well. Also checked the transformers if the little thermal fuse is open, but no dice there either. Now I think is has something to do with the driver card.
There is a driver card soldered into the middle of the PSU. It consists out of a PWM for the booster, op amp, timer and comperators. Complicated thingy!
Anyone has a schematic for this PSU would be greatly appreciated!
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