CurtPalme.com Home Theater Forum

stefuel · Posted: Sat Jun 05, 2010 11:48 pm Post subject:

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Picking up bad LCD monitors and fixing them by putting a few caps into them, and then reselling them, is a pretty decent way to make a fast profit. It's not a bad business to get into.

If I wanted to do it, I'm well positioned to do so. There's a local electronics recycler that gets LCD monitors in from customers by the pallet load. Many of them are due for caps. I could buy them all day long for 15 bucks each and fix them in 20 minutes with 20 dollars
worth of caps (or less) and flip them rapidly for 99 bucks each or more. A lot more, in the case of the larger widescreen monitors.

CJ

stefuel · Posted: Sun Jun 06, 2010 9:54 am Post subject:

OK Curt, spill the beans. What's the problem with this projector. I'm starting to lose faith Laughing

**Curt Palme** · Posted: Sun Jun 06, 2010 10:12 pm Post subject:

OK, I'm finally into the beast. Looks like Craig wins the prize, I'm about to change out the red tube. What I did so far:

-change the convergence and deflection board at the customer's house.
-swap the HV leads between splitter connectors.

No change.

I've now:

-swapped CRT socket connections on the motherboard
-swapped focus lead connections on the focus block.
-confirmed that the red tube does not go out of focus at high contrast.
-swapped yokes.

No change.

For the life of me, I can't figure out why it could be the tube. Unlike standard CRT monitors, there's no shadow mask that could cause problems when hit hard (high contrast).

About to take some pix of the misconvergence to post here, then I'll swap the red tube.

**Curt Palme** · Posted: Sun Jun 06, 2010 11:55 pm Post subject:

Pix of the original tube. Ignore the minor convergence issues, didn't do a perfect job, but you can see that the red flares all around at high contrast.

**Curt Palme** · Posted: Mon Jun 07, 2010 12:28 am Post subject:

Sumbitch, it was indeed the tube. Go figure. Solid as a rock now.

stefuel · Posted: Mon Jun 07, 2010 12:37 pm Post subject:

**Curt Palme** · Posted: Mon Jun 07, 2010 12:39 pm Post subject:

I am guessing that something in the electron gun is loose. As I said, I did a crappy quick job on convergence, as all I needed to see was if the red would shift.

Replacing the tube also solved the intermittent shutdown thing. It's been running fine overnight. Strangest repair ever, I think, since I can't explain that one..

CIR Engineering · Posted: Mon Jun 07, 2010 1:35 pm Post subject:

**Curt Palme** · Posted: Mon Jun 07, 2010 1:53 pm Post subject:

Well, I was stubborn and I did indeed dance around it before swapping the tube. It's really easy to change the tubes in this set though, so I spent maybe an hour on the set in the shop. I'd still like an explanation of why, and thanks, as if you hadn't posted this, I might still be fighting with it.

Curt

tse · Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.

It still looks like a bad connection in the anode circuit. Somewhere in the tube between where the anode connection is made and the screen. Double check the anode cup before you toss that tube. I've seen tubes where the cup is RTVd on real good but the little hooks weren't snapped into the little ring. They would do the dark picture ok, bright picture big thing.

Scott