WD-73735 Bulb will not light Error 66 Please Help!


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ourlivinghome
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WD-73735 Bulb will not light Error 66 Please Help!

Postby ourlivinghome » Sun Sep 18, 2011 9:29 pm

I have a client's TV that I'm trying to repair. It sits in a bar with no A/C in hot hot 110 degree Texas summers, and had never had the dust cleaned out. A previous technician replaced the bulb and when that didn't work said they must need a ballast. He was unreachable after that, so that's when they called me. I don't normally repair TVs, but figured I'd give it a try. Sounds like fun, even if just for the learning experience. And I've learned a lot so far!

This post has been up for a while and there's been no response. So I'm going to update it and shorten it a little.

I've been getting error 66 the whole time. I replaced the ballast. Still no worky. I read up a lot more here and in the service manual. I was getting below 320v DC to the ballast. So I replaced some Caps on the PS board. It helped for a while. TV even fired a few times. Then the voltage to the ballast went back down even below 300v. So I bought a new power supply board from ShopJimmy.com. Now I'm getting 335v+ and down to about 328 when actually trying to fire. Haven't gotten it to light once since the new power supply.

I've measured, and seem to be getting 5v for the Lamp Enable signal at the tiny connector on the ballast. Color wheel spins. Everything seems right, but the bulb still doesn't light. It looks like the Conn's technician just replaced the bulb and not the entire housing. The housing was still dusty, and since the bulb is not actually sealed and seems to have holes for ventilation, it has sucked dust inside the bulb. It looks fine though, not cloudy at all anywhere.

What can I possibly do next? I'm now stumped. I know I can't test the leads going to the bulb itself, since I burned up a DMM already trying that. What else could it possibly be?!?! Maybe the Conn's guy used the wrong bulb? Or the Low DC Voltage to the ballast somehow damaged the bulb? But it was lighting 5-10% of the time a few days ago...

Surely someone here has dealt with a similar problem. Can anybody offer any piece of info here please? Thanks very much!!
Last edited by ourlivinghome on Fri Oct 21, 2011 7:52 pm, edited 1 time in total.

ourlivinghome
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Re: Mitsubishi 73735 Bulb will not light

Postby ourlivinghome » Wed Oct 12, 2011 9:01 pm

Alright, so I replaced the two capacitors on the PS board that looked bad. Still not getting the bulb to fire. I'm tempted to just buy a new PS board to replace it. I would really like some confirmation that I'm on the right track.

We have a new bulb and a new ballast. When I turn the TV on it cycles 3 times. The little part on the ballast that is supposed to light up and kick on the bulb never does. I'm getting 317v to the ballast from the PS, and 5 volts on the smaller connector that seems to be the Lamp-Enable from the DM.

What else could be causing this TV to not fire the bulb??? Any help is greatly appreciated!!!

detox
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Re: WD-73735 Bulb will not light Error 66 Please Help!

Postby detox » Thu Nov 24, 2011 7:09 am



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