May need to change the DCU as a complete item, then obtain an overlay for
the set to proceed with a complete registration adjustment.
wrote in message
oups.com...
Hi;

I Tshot it for the usual convergence job, had the usual bow which is
characteristic for this failure in sets that use convergence for T/B
pin correction.

The other guy changed the ICs, and one resistor. Now the convergence is
really whacked out. Looking at it I know why the ICs went, they are
being driven with some totally whacked out waveform. What is obvious is
that the convergence data are screwed up, I mean if you ever did acid a
crosshatch on it might result in a flashback. It's funny, but this
thing is so whacked out it is almost artistic ! If we wind up replacing
the DCM I want the old one. Actually I would only need the EPROM, put
some water cooling on the STKs and build it into my wall. I'd take the
whole set but I guess I would have to buy the customer a set, minus the
repair cost. I might make due on the $6 EPROM if I ever even do this.

I can tell that all six channels are working, and I can tell the DCM is
feeding it, and the only way for this particular error to happen is
corrupt data.

Is there a procedure on board that I can do to reset the data to
pre-factory alignment values ? I'm not afraid to do a full alignment,
even on the whole set, but the service manual isn't very clear on this.

If I lose the option data, especially if the procedure doesn't reset
the convergence data this would not be good. Actually it would be quite
difficult to even read the option data to write it down.

EPROMs just screw up sometimes, we've seen this in RCAs, when you don't
bother to replace it, just re-initialize it.

Does the procedure exist on this set ?

Thanks in advance.

JURB