"N Cook" writes:

Sam Goldwasser wrote in message
...
"N Cook" writes:

Eeyore wrote in message
...

N Cook wrote:

There are 3 HF transformers

More likely one transformer and 2 chokes, unless you have a specific
reason to say otherwise.

Why would chokes bridge the "no man's land" isolation strip between HV
and
LV areas ?

No, probably transformers instead of opto-isolators (on the feedback
and drive).

Personally, I wouldn't even attempt to do any serious troubleshooting
on a supply of this type unless there was no inexpensive replacement.
I would check the obvious - ESR of e-caps, open high value startup
resistors, and such. But beyond that, these tend to be infinite
frustration sources.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/

I don't mind challenges unless someone wants a turnaround repair, which this
is not. Its just practise for some future dedicated complex supply that has
no generic replacement.
I can see the one large and two small HF transformers tied up with the above
process but I wonder what the 4 pin opto device is for, perhaps an overall
on/off killer: when the controller flag is high it locks out the main HV
oscillator from making any blips.

Could be, since the transformers can't provide DC coupling.

The problem is that with no schematic or service manual, there can be
so many dead ends and confusion that the experience IMO may not transfer
to other areas. It's not clear that the knowledge gained is worth the
hair lost.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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