FIXED HP Integral PSU repair

[Hiwi]

Hi all,
i have a non working psu from an HP Intergal on my bench.
I did a sucessful repair of another PSU but this is a very hard case.

So is there an engineer with some more experience?

What i already did:
The psu has no output voltages, i just ticks in an intervall of a second. I think it wants to start, but maybe there is a short, but i can't find it.

High rectified voltage (324V for 220V Europe) is ok
There is the start peak voltage, which i can see on my oscillocope.

The start circuit delivers a voltage for a period of time to start the PWM MC34060A.
The MC34060 is then powered over a special aux voltage.

I checked nearly every diode and transistor, the optocouplers and the thyristor in the crowbar circuit and the triac in the mainline. I desoldered every component and made test circuits for the optocouplers and triacs/ thyristor, so i can be sure they are working.

I changed the opamps and now waiting for a MC3460A from China, this pwm circuit is out of production. I hope they are no fake chips.

Has anyone experience with this psu. I have heard of many dead psu's in this machine.
A service manual can be found in the net.

Ralf