Common causes are the lamp failing, and or the lamp power supply
failing. Servicing the power supply is not easy. It will need a proper
test load, or the lamp to load it for taking measurements.

There are safely issues involved when working on these. The factory
service tech will start by changing the supply if a new lamp does not
work properly.

--

JANA
_____


"GregS" wrote in message
...
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