I got one with bad yoke, this chassis is typical "awful" kind with two
STK-792 that always blows out, horizontal circuit is seperate from HV
transformer also has own transistor.

The transistor on heatsink (front right if viewed from back) that
couple the inductor regulating supply for the rest of horizontal
circuit for the yokes shorts instantly and the large transistor heats
up excessively on the larger heatsink in middle.

Groan, one of three yokes is bad, how you go about to locate bad yoke
without blowing things up too much?

I already ordered and got a new yoke, two more transistors and a
resistor.

Thanks!

Note this is chassis that is 3 piece type, from right to left: SMPS,
deflection board then mainboard (metal boxes). Fairly commmon design
in Samsung's 42", 52" and 62".

The layout have not changed at all on the deflection board. working
from back toward front: pair of heatsinks for convergence amps,
medium sized heatsink with HV transistor & 2 diode for HV, then middle
for another medium size heatsink driving yokes. Blah blah.

Cheers,

Wizard

Flyback Tester will Ring the Horiz coils of the Yokes Also, indicating the
respective quality. Basic resistance checks may qualify depending on the
accuracy of the meter being used. Again, measure all three and compare, if
one is defective there should be a difference, however, very minimal. The
convergence sections of the yokes can be measures with resistance checks,
again comparing each.
Another frustrating problem with Samsung RPTV is the fact that the tubes do
leak, with the fluid going normally down into the yokes, onto the crt drive
boards (available as a set of three with cables), and anywhere else within
the set as it has a chance. If you find any evidence of liquid leakage do a
through inspection to determine just which of the three may have leaked and
go from there.
"Jason D." wrote in message
...
I got one with bad yoke, this chassis is typical "awful" kind with two
STK-792 that always blows out, horizontal circuit is seperate from HV
transformer also has own transistor.

The transistor on heatsink (front right if viewed from back) that
couple the inductor regulating supply for the rest of horizontal
circuit for the yokes shorts instantly and the large transistor heats
up excessively on the larger heatsink in middle.

Groan, one of three yokes is bad, how you go about to locate bad yoke
without blowing things up too much?

I already ordered and got a new yoke, two more transistors and a
resistor.

Thanks!

Note this is chassis that is 3 piece type, from right to left: SMPS,
deflection board then mainboard (metal boxes). Fairly commmon design
in Samsung's 42", 52" and 62".

The layout have not changed at all on the deflection board. working
from back toward front: pair of heatsinks for convergence amps,
medium sized heatsink with HV transistor & 2 diode for HV, then middle
for another medium size heatsink driving yokes. Blah blah.

Cheers,

Wizard

That was lucky one, the green yoke horizontal (pair of windings, the
one halve of horizontal windings went partially toast-burned style
that toast is ok in the middle with bitter, black burnt edges.

Replaced resistor, two transistors and fix the loose connections on
red yoke plug now I have a samsung projector that is functional.

Gee, that is very lucky that owner didn't have to pay for a CRT!

Most of time I see bad yokes with invisible fault. Oh, I don't have
tool to check the windings, that why I asked for suggestions.

Thanks all.

Wizard