Why lamp turns purple and then shuts off after 15 minutes is it a bad bulb

I seemed to have had the exact same problem... I had placed the projector on top of a small book (to raise the unit), however, did not rest the feet of the projection unit on the book and it overheated and turned off, as a result. (The bottom of the unit was making direct contact with the book which caused it to overheat since not any air was passing through between the two)

After letting it cool for a while and powering it up -- it would usually power off completely for about 15 minutes. After a little thinking, I thought it may be the lamp/bulb and waited a couple of years and bought one online that arrived yesterday.

I installed the new lamp/bulb this morning and it did the same thing. It powered down about a half hour later. Bummer.

I reset the machine to factory defaults and checked to see if it had the 1.03 firmware... It did

Then went through the settings in the setup area and turned off the 'prevent pic screen saver'... Reset the 'lamp hours'

I doubled checked the lamp/bulb installation... Turned it back on -- same thing -- it shut off after about 15 minutes or so... Then unplugged the unit and turned it over and took out the 4 or 5 chassis screws and loosened and took off the side panels and blew onto the fans and circuit board areas and gently pounded the sides to shake anything that shouldn't be there loose and put it back together.

i powered it back on and now it's been working for about 2 hours and 16 minutes!

good luck!

possible new bulb bad or a issue with the optical light engine.

hi when you replace the lamps, the lamp counter needs to be reset,thanks

shaun

Hi,

First step is to unplug the 120 vac power for a few minutes to clear any corrupted data that may be present in the controller circuits.

If a "power" reset doesn't help and the lamp or bulb is installed correctly, you most likely have a failed replacement bulb. The symptoms are all standard indications of a failed bulb.

Reduced lamp life can be caused by:

1. Lightning and other 120 vac power bumps.
2. Collisions with vacuum cleaners or other incidental impacts while the TV bulb is operating.
3. Starting the TV without a complete cool down. Bulb will consume a small amount of mercury with each start. Excessive consumption occurs when bulb is "Hot" and turned on.
4. Wrong bulb installed as replacement.(Philips original replaced with Osram or El Cheapo)
   
5. Poor quality or damaged bulb installed as replacement.
6. Bulb damaged during replacement
7. Bulb installed incorrectly at replacement.

Almost all Hitachi 55vs69 "No Picture" failures are related to the bulb.

Many of our service events are with customers that purchased El Cheapo bulbs from "shopping cart" websites or picked up a bulb from a small "local" TV shop. Many small shops stock of 3 or 4 bulbs and try to substitute or cross reference to fit more than 200 models of TVs from 7 different manufacturers. If a premature bulb failure occurs, they have the opportunity to sell you some expensive service.

Go here to see all of the different Hitachi TV bulbs that are available in Canada.

Find Your Lamp
Use the correct bulb for your model and if you are uncomfortable with the replacement procedure, get local service.

defective lamp and/or ballast

Your projector most likely has a bad ballast board(lamp power supply) that is the most common cause of this problem. The reason why this happens is because the lamp is drawing more power than usual and hence the protection circuitry will shut down the projector as precautionary measure to avoid damage to the components.

Hope this helps,
Sai.

the switch is bad or wire fell off

if you purcased a LTI lamp then the possibilty of a bad lamp may be the case. LTI lamps are cheap and are poorly manufactured. if it is a JVC lamp then you may have further problems such as lamp balast, or thermal sensor. clean the fans and filtersfor better air flow. keeping the lanp cool is important for the life of the lamp.

DLPs have flow chart trouble shooting techniques to pinpoint exactly why your set isnt completeing the boot sequence. If you would like the service manual for your model let me know and i will post a link where you can purchase a complete one.

Sounds like the lamp to me. The projection lamps get hotter as they age and the TVs have a sensor to monitor the temp and shutdown the TV if it get too high
Projection TV makers charge an arm and a leg for their replacement lamps. They make it easy to do but as a result the custom lamp assy is expensive. The trick is to buy just the bulb for your model TV from any number of us aftermarket sources at a fraction of the lamp price and install it in the old lamp yourself. Really easy.