Philips Monitor (Black) VG0060-80 Power Stage Repair, the Monitor turned off unexpectedly without any suspicious noise.

This power stage is practically identical to other monitor models, for example: Philips CM8833 and Commodore 1084, but surely there will be others that mount the same power stage.

Repair:

After removing the PCB of the power stage i took the opportunity to replace also the power switch that no longer worked properly i also replaced the exploded fuse but obviously nothing worked.

The fault was due to the TS132 transistor completely short-circuited, the diagram says that a BU806 is installed but instead a 2SC3795B is installed.

Replaced, still nothing works, i tried with the tester but i don’t find any voltage, even the 300v +/- on the capacitor C112 at this point in addition to the diode bridge (D107/D108/D109/D110) there was only the 47 Ohm 7W resistor R103 to try and in fact it was interrupted, i replaced it with a 5W one, i didn’t have a 7W one in the lab.

I used the old trick of the 100W bulb in series, in my case instead of the fuse to avoid destroying other components.

Everything worked perfectly, the bulb turned on for a minimum amount of time and then turned off and the output voltages of the power stage are all present (125v/15.8v/25.5v).

Gallery:

Download: Philips VS0060-80/CM8833/1084 Schematics (286)