Danny,
This looks exactly what I would have posted, I have one doing the
exactly the same thing. It first had bad green conv, I mean really
out on the green, Found one of the 1..8 ohm open, checked all the
caps around, visually that is... didn't pull any... all looked OK...
found one of the STK mods shorted, ordered a set of the 1.8 ohm flame
proofs, all six, cheap enough. Also ordered one of the STK's from MCM,
problem fixed, so I thought. About a week later customer calls back,
went out, noticed that one of the 1.8 ohm resistors that I replaced
was 'toasting out' checked it, it read around 2.2 ohms... so... I
ordered both STK's figuring, that, perhaps, the mate for the other
side was toasted as well, "I don't have a schematic for this beast'
but, followed the traces back, looks like the 3 amps in each module
cover the three colors in some sort of push pull arrangement. Well,
after replacing both units the problem still persists. I haven't been
out yet to check, customer lives a ways out and I really don't want to
try to lug the entire unit back to my shop, figure to would do more
damage moving it. I've been just pulling boards and bringing them
back to my shop. can't really fire them up here at my shop, so, it is
just go over them with my meters. The one I have will run fine for
about 5 minutes and then begin to drift out slightly on the red, top
left side of the screen. I did notice that the STK's run pretty warm.
I did the convergence from the remote, the one that comes up with the
1 thru 9 on the screen, set also has a auto focus button, not sure how
that works with the CPU, might be that we have to put the unit into
some sort of primary convergence mode. I've heard that there is some
sort of overlay that goes over the screen and that there is a 'secret'
command string that you enter into the remote to get it to go into the
crosshatch pattern. Perhaps this needs to be done to lower the
quiescent bias currents of these circuits. I feel that perhaps it is
just in need of better alignment. I've seen convergence ckts in some
commercial cameras that would do the same sort of thing, run really
hot if not aligned properly, this really goes back when they had
literally dozens of control pots to do the alignment. Do you know how
to get this into the secret service mode?
Why am I replying at 4 in the morning, just had jaw surgery and
couldn't sleep... one good thing, no cancer,
Take care,
Markus
of 1.8 ohm resistors and On Mon, 26 Sep 2005 11:48:32 -0500,
