Hi,

now after recieving a much more useful answer from another KME employee
i now have a somewhat blurry and hard to read schematic and parts list,
which identifies R9 as 470R 0.5W.
Soldering in one brought back a perfect picture after fiddling with the
brightness control. However, the picture just lasted a few more seconds,
until R9 emitted smoke and flames :/
I dont remember if there still was any picture, i was too busy with
pulling the plug at once...

So, second attempt.
Figuring out the mentioned hybrid is responsible for dynamic focus, i
disconnected it and bridged over the connections to the focus pot.
Another new R9 and put everything back together again.
Power on, useful picture even without DF, then smoke again.
So the Hybrid probably isnt responsible.

Which leaves for failing short after a few seconds:
a BA159 (1A 1kV UF) diode that tests well and wont fail given the
limited current and if it fails, itd be shorted right away
some 630V film capacitors, which test okay, and would rather loose
capacitance but not fail that way

the Focus pot (which looks like its okay but could fail at high voltage,
perhaps.I couldnt hear/see any arcing to occur, but further testing is
rather limited cause burned resistors smell real bad and my roommate
complains about the smell by now.(he doesnt complain about the stack of
various, open electronics however).

The CRT.Is it common for a CRT to short out between screen and/or focus
and heater/cathode?It tests all right when cold, i dont have the
equipment right here for doing more sophisticated testing (well, at home
id have most thats useful, including a variable HV power supply up to
2.5kV).


//some further testing:

With CRT neck disconnected, it still burns.
So the CRT likely isnt faulty.
I guess im gonna unsolder the focus pot now

//Even more testins after my roommate left for his girlfriend
//this is turning into a live report

Focus dusconnected, stil burns.
Surprising how often and how bad a single reistor can smoke without
changing value too much

//Even further testing
This time i gave up on the diode and substituted some SMD diode from the
PFC boost converter from an electronic ballast i decided to be good
(itll have at least 600V and it has to be fast).
Now with CRT and focus connected back, but without DF hybrid (i dont
want to burn it).
Guess what: it works!It doesnt burn up and produces a good picture
(rather sharp actually, i wouldnt see much need for DF).

Whatever happened to the diode...
It tests perfectly on a multimeter, im going to bring it to the uni
tomorrow to see if they still have that neat old TEK curve tracer and
could test my diode.

For the monitor, i guess im gonna have a look for some MUR1100 or
similar and a flameproof 470R resistor.I cant really leave the SMD diode
in there, mostly because it is just hanging from 2 wires on the back
side of the PCB.

Lesson learnedont be too sure that some component that tests okay and
normally would fail in an obvious way is okay...

Regards, Robert