16.1 PSU 1040 STF

How to repair the 1040STF PSU

So i will have a look to the old psu from a 1040 STF :

R8 is a safety resistor with 1 Ohm in line to a Transistor BU508 (Q2), the driver of the pimary side o the transformer. I think your psu lost his primary clock.
Check R4 (330 Ohm, 2 Watts)
If that resistor OK check Q1, 2SC1384.
Check D1, BYV95A
Check PC1 (SHARP PC817)
Check Q3, TL431 (TexasInstruments)

Check R1, 5D-11 (NTC)!

Check DB1   and   are 120V AC IN
+ and - are 120 DC OUT

C4,C5 (both 47uF/250V) must have around 150VDC and more!

I hope you found the parts on your pcb. If not, you have another psu!
Do not touch anything on pcb while the psu is pluged in!

Don't touch the heat sinks!
It's more as 200 V on it!

If you can't found any defective part, replace the psu.
(A chance you lost the transformer..) (To expensiv, get a new one)

Remember that primary power in can be 115AC up to 240AC in. Parts after transformer are all the same.