OK, I'm baffled, after exchanging the semiconductors (transistors, diodes and all the IC except the NE5560N that didn't arrive yet) the behavior is EXACTLY the same
That is, powered on from the mains, the kick-start circuit, tries to well, kick-start the PS, the voltages are coming, and then are going down, no abnormal power consumption, nothing.
If I power the 14V from an outside PS, as recommended in the service manual, everything is there but no power is delivered, just some pathetically small output voltages
, I'm at the end of my wits
.
So now I'm offering a
BUG HUNTING BOUNTY - I'll PayPal/GitCard/Amazon WishList/whatever on the tune of max. 10 EUR for information that will lead to the bug killing, that of course does not includes the eternal gratitude
.
The NE5660N controller from Phillips is way too "analogiky" to me, and in the actual schematic I have very few cliúes how the "C - Buck Regulator" block is even biased, only that the voltage on the 5V1 Zener is around 3 volts. It does send a lot of pulses on the new MOSFET but this doesn't produce too much output
.
I can make measurements and post oscilloscope screen shots and also do sensible modifications tomorrow at request. Really this design is pissing me off and I've never encountered until now this controller.
Any takers are welcome, I'm on verge of throwing the junky board in the electro-garbage and implementing a new PS, if not for the CRT high voltage,.
Waiting for your participation,
DC1MC
P.S> If the winner is not interested in the 10EUR bounty, he can redirect it to a charity of his choice or to a forum member with less means.
Also, if anybody around Mannheim that wants to get some beer/würstchem/cola, has experience with SMPS using this chip and want to give it a try I can travel to him on this Sunday.