Re: G05-802 TIS98 cross reference

On Apr 3, 5:13 pm, James Sweet <jamesswe...@xxxxxxxxxxxxx> wrote:

If parts burned up then you have a short. Did you check both junctions
of all the transistors with the diode check on a multimeter?

Apparently I missed one..... and that was enough to cause the havoc
again once I fixed that trace.
Q606 was shorted between C and E. And I recall checking everything BUT
that junction.

Do you have horizontal deflection all the way across the screen, or do you have just a flat line or a quadrant of the screen with something resembling a normal image?

It was a horizontal line all the way across, could see motion, just no
vertical deflection at all.

For that trace to burn, you'd almost have to have a shorted chassis transistor.

At one point the 2N3792 for the Y axis was indeed shorted. So that
burned traced may have happened then, but I just didn't find it
sooner. (during the first flame up episode)

Such is the nature of power electronics that failures often cascade. You
can fix 99% of the problem but miss one bad part and everything blows up
again when you apply power.

Oh yes, and that it did again.....
R605
R608
R613
Q605
Q606
Q609 - 2N3792
F600

So where does that leave me now.... well, spot killer is off, I have
image on screen, no fire or smoke..... but only the lower half is
producing any image.
Full width, but vertical is only the lower half of the screen.

Also noted that R602 didn't seem to have any affect on the image at
all. I had checked the pots earlier, but maybe I need to look at that
circuit again.

.

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