On Sun, 18 Mar 2012 10:03:17 -0700 (PDT), klem kedidelhopper
wrote:

When my son was given this set last December it had a four blink code.
I removed and disassembed the fan in the back of the set, cleaned and
relubricated it and reinstalled it. The set worked for three months
and then intermittently began doing it again. The other day I re did
he fan, (even though it seemed to be spinning fine) and the set again
worked for two days without any problems whereupon it then started
failing again. Someone suggested that this code could also be a "door
problem". Is this the door in front of the lamp that they were
referring to that could get overheated and distort?

I'm assuming that the fan outputs some sort of a pulse train on the
third wire which the micro must look at. Is there any way to
definitively rule out a fan problem such as by looking at this signal
with a scope to ascertain if the fan is indeed the problem? Admittedly
I have been chincing on this repair in relubing the fan twice now, and
I don't mind buying a new one if that is indeed the problem. I just
have my doubts though as the fan is turning quite nicely by hand.
Thanks for any advice. Lenny
The service manuals for many TVs are available free at
http://elektrotanya.com/. In many cases the schematics are quite
detailed. Without knowing the model number or technology I would
hesitate to guess.

PlainBill