Classic II Analog Board / no output

[bibilit]

I am trying to fix a Classic II Analog Board, the primary side is ok and the fuse also, but i have no output on the secondary side (0 volt)

Removing and replacing capacitors didn't solve anything, probably a faulty component, but don't know where to look next.

 

[bibilit]

Not fixed this unit yet, but had another one to repair, blowing fuses all the time.

My first bet was that the bridge rectifier was bad, and at first check - and + where shorted, but on removal all was ok.

Turned my attention to surrounding components, in the end The Mosfet on QP2 was shorted (IRFBC40).... a swap, some new caps on the Logic and Analog board and i have a nice working unit



Already been talked about here, so this Mosfet has a tendency to go bad.

 

[uniserver]

yea seems like the 230v ones.... including the Color Classic's,  they get hard parts that go out.

 

[bibilit]

Thanks Uni.

Any idea why the first is no delivering any output ?

 

[uniserver]

the opto oscillators go on those 230v AB's. might be something to look at.

 

[bibilit]

Ok thanks is this the CNY17G-3 ?

For my information, is this component acting as a switch ?

Also, do you know the difference between the CNY17-3 and the G variant ? (as the first can be found easily)

Thanks again.

 

[bibilit]

No luck here.

I saved one board yesterday, but replacing the Optocoupler in the others didn't solved the issue.

Any idea where to look next ?