Title pretty much sums it up.

I have a Pixelworks board driving a 15.4 WUXGA monitor. It's one of the older ones with a single HDMI port and if I remember correctly only 128MB of memory. When I power everything on, the picture starts showing on the wall as the bulb starts warming up and everything looks great. After about 20 seconds, the image locks up. It continues to display the same image, but after a few seconds it starts fading to white.

I originally thought it was a heat issue, so I swapped out the fan I had in there for a 120mm 100 CFM fan. Things stayed the same. Then I thought it might be that the board itself was getting too hot, so I propped up the original 120mm fan (probably around 40 CFM) on top of the heatsink of the Pixelworks board. Still no change.

During my testing at one point, I started up the board too soon and the lamp didn't fire. The LCD ran fine for several minutes. When the bulb re-struck, I got the same approximately 20 seconds, then the display locked up again.

When I received the board originally and tested it out, everything seemed fine. I played some video on it, and some Guitar Hero. No problems at all. It has been sitting in a box for about a year since then though, so I don't think there is any chance of returning it or getting any support.

Does anyone have any ideas? Is it likely the board, or could it be the LCD? I'm fairly certain it's not a heat issue at this point. Could it be a power issue? I am running a fairly beefy 12V power supply, and like I said, the board seems to run fine as long as the bulb isn't running (fans were still on though). The only things I can think to do now are either move the board outside the box to see if it is a heat issue, or rewire the 12V power supply so that it's not on the same circuit as the ballast. Either one seems like a stretch, not to mention quite a bit of work...

As I'm writing this, it just struck me that I should try one of the other inputs on the controller. I'll try that tomorrow.

I hope someone can help.

Hey! You joined on my birthday. That means I'm honor bound to concoct some totally stupid explanation for your woes.

You're certain it's happening only when you fire your projector lamp? This has happened from the get-go? Your system never functioned properly?

Off the top of my head I don't remember if an overheated LCD turns black or white but I thought it was black/dark.

Fades to white - you mean the entire image fades homogenously to white or does it start in the middle and spread or something else?

Since it locks up first that seems more a power issue to me than something thermally aggravated. But it seems odd it's somehow tied in with your lamp running or not.

Do you have a non-contact thermometer? Can you unplug your LCD power supply and use an extension cord to power it from a circuit separate from the lamp ballast for testing purposes?

Just thinking out loud . . . I'll be back.

The first batch of Pixelworks boards were very temp sensitive. They will freeze and the menu settings will randomly change and save. Go find the Language change menu and remember it's location. Now do a factory reset. When it comes back up everything will be in a form of Chinese. Go back to the Language setting and cycle back through until English shows back up. It might take awhile. Mine has ~20 languages to cycle through to get back to English.

Do you have the controller in the lightbox area, or the cooler area up front? A fan alone will not help if it is in the rear with the bulb.

An overheating LCD goes black.

You can make it work with the controller in the light chamber, but you will need to shield it with a metal barrier and add a way for cooler air to pass over the board.

If it is from the Johnzo group buy it will still need a fan on the processor to run at 1080p without freezing.

Electronic or magnetic ballast? I know that my eballast plays hob with electrical interference, it affects my TV every time it goes on. The controller for my Samsung monitor doesn't like it much either, I had to put an EM filter on the PSU, and enclose the controller in a metal box.

heat is also not a good thing for these, and getting it a source of cool air could help.

Fairly certain. I have all weekend to work on this, so I am going to try many different combinations of inputs/light on or off settings.

The image holds the way it is for a few seconds, then slowly (over a period of several seconds) it gets progressively brighter and more washed out. I've only let it stay like this for a short time as I'm worried about damaging something... It did seem evenly distributed though.

Yes, I'm going to pull it out tonight and verify whether this is a heat issue or not. It really doesn't seem like it as it is such a short time between the lamp striking and the image freezing, but I'm going to test in order to be certain.

Good advice... I will try to reset the controller to defaults and see if that makes a difference.

Up front. I've attached pictures to this post. Just your standard dog coffin with air vent in the top and a fan sucking out the back.

Not from the Johnzo group buy, but definitely that vintage. I was wondering also if this could be an HDMI or a 1080p issue. I'll try just feeding it component output from my Wii or maybe some SD from the PS2 and see if it makes a difference.

It's an LL E-Ballast with 400W LL bulb. I was leaning towards some sort of interference as well, but I really have no way to test for that. Again, I don't think it's a heat issue (at least directly from the bulb) because of the short time between the bulb firing and it locking up. I'll stick some temp probes in there though just to be sure. BTW SupraGuy, I'm in Alberta as well. Maybe you want to come over and troubleshoot for me?

I just wanted to say thanks for all the help so far, and thanks for the great community here. I've been lurking and planning for a long time, and the amount of information, and knowledgeable people on these boards is astounding.
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The wiring is kind of a mess at the moment... All the rewiring I've done so far has wreaked havoc on what was once at least sort of organized.

Just replying again so I can add one more picture. The LCD frame is sitting on blocks and has a gap under it that extends most of the way across the box. Air path is the standard down past LCD, up the other side, then out the back. The top of the LCD frame is pretty snug against the top of the box, but I could throw some gasket tape on there just to be sure.

Through the air duct you can see the support bar that's holding up the front fresnel. The hole starts pretty much exactly in front of the LCD.

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I'll keep testing, and post back with my findings.

Have you tried striking the bulb, giving it 10min or so to stabilize, and then starting the controller? Also, try powering the E-ballast temperately off of a separate circuit. Run an extension cable from another room and power the ballast from it, for a quick EMI check.

I had to buy a small 40mm fan to use HDMI 1080p with mine. It would lockup very fast without it. It was fine with anything lower res though.

Good luck.

Well after a few hours of exhaustive testing, it does seem like a line noise/interference issue.

Tried resetting the LCD to factory defaults, no change. Tried running different resolutions, no change. Tried different inputs, no change. Tried no inputs (just using the menu), no change. Got out the temp probe, watched the controller board heatsink go from 70F to 85F in under a minute before locking up. At this point I thought it was a heat issue. Repeated the same thing a few times and had it fail at nearly the exact same temps, at the exact same time. And still thought it was a temp issue.

Then I tried moving the bulb to it's own 120V circuit, as well as pre-warming the bulb and letting it stabilize before starting the LCD. It ran for 5 hours with no problems at all.

Today I'm going to see if I really need to pre-fire the bulb, or whether having them on different circuits is enough (my entire basement is just one circuit, so not really a separate circuit, but a separate power cord). I still need to throw in my reflector, and tweak a little to see if I can get brightness a little more even, but I think it looks awesome for a first attempt.

Thanks for the advice from everyone.

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