GregS wrote:

In article gunRj.9380$E77.5795@trnddc05, "James Sweet" wrote:


"GregS" wrote in message
...

Working on a DLP projector, no light. I don't measure any voltage
going to a lamp socket with lamp disconected. I looked for both AC and
DC.
Looks like there is a ahole board for the supply with OSRAM parts.
Anything else to check ?

greg

You could find the signal line that triggers the lamp driver to turn the
lamp on and make sure it's changing states when the lamp should light.

Be *very* careful probing the lamp sockets on these, a properly working
driver will supply pulses of several kilovolts to ignite the arc in the
lamp. You can easily fry your meter, or worse.

The drivers are essentially switchmode power supplies configured to supply a
constant current rather than a constant voltage. Standard SMPS
troubleshooting applies, taking into account the greater than usual high
voltage hazard.


I used an old analog meter. There is a LED lamp on indicatior on the top of
the unit, and it does go on. Evn if I just had a bad lamp, I would imagine there would
still be a clicking or visable arc around the lamp. $435 for a new lamp, wow.

greg
Ha, Sounds like you have an RCA 61 inch? , that is what my DLP is. and
it cost that much for a replacement lamp assembly..
Your problem sounds like a ballast/driver problem.


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