On Mon, 21 Dec 2009 08:13:40 -0800 (PST), jjh
wrote:

Thank you, and a follow-up question*

Next look at the leads from the inverter to the CCFLs (backlights).
Usually the wires are in pairs. *If the wires in the pairs are of
different diameters the smaller diameter wire is the return line.
Measure the AC voltage on each return line as the backlights are
operating. *(Yes, you only have a few seconds). *Normally each wire
will have the same voltage; you are looking for the one that is
noticably different than the others.


Measure across the return line to what? Is there a well marked
grounding point on the board? Or should I just measure across the two
wires to see what voltage the lamp is getting, and look for one with a
significant difference among the others?

Thanks you all for your pointers...

If the CCFL's are bad, where is a good place to buy replacements at a
reasonable cost?

TIA,
John
DO NOT measure across the CCFLs. Unless you have a DMM designed for
2KV AC this could destroy your DMM. Measure from the return line to
ground. The metal chassis is a good point. Quite often the circuit
boards will have a small grounding tab under one screw. I use the
head of that screw as a ground point.

Google 'CCFL backlight', you will find several vendors who manufacture
CCFLs in a variety of lengths and diameters. Based on my experience,
the CCFL is one of the least likely parts to fail. Transformers and
wires are more likely causes of the 'two seconds to black' symptom.

PlainBill