First post. Looking to help narrow down my issue.
Let me start by saying "I know....use the search function."
I've been googling this problem for over a week, every night and am still unsure what to do.
Here's the details.
Samsung 50" DLP
Manufactured in 2006
Got it from a guy I work with.
He said a while back it would just 'shut off'. Would run for hours then screen just goes black, still have audio for a few seconds then unit shuts off. He said now it's every 10 minutes or so and just bought a plasma.
Currently have zero $$ invested other than a thermostat (which didn't obviously work).
When turning the unit on at first, the lamp light flashes, I get the 'jingle' (if you will) and hear something spinning up (or so it seems), then a pause, then another spin up (sounds like a hard drive to be honest...I work in IT, but I don't see a HDD anywhere inside the unit. Seems that it's either the color wheel or ballast making the sound, but cannot narrow it down). Lamp turns on, dim at first, then comes on fine and the lamp light on the front of the unit goes out. Appears to be functioning fine.
Unit runs and processes HD programming via component cables (Directv HD box) for approx 10 minutes. Brightness looks fine, picture quality is great.
Then "POOF", screen goes black, still get audio for a few seconds and then the unit powers off and all three LED's on the front of the TV power button flash. Unplug, let sit for a minute, fire it up again, repeats process to a T. However, when the TV is warmer it SEEMS to be somewhat shorter time before it shuts off.
When I first got it home I took the back covers off and blew out all the boards/fans, etc with an air compressor, keeping the volume of air down to not damage anything. There was significant dust/debris, but not more than I've seen in PC's by a longshot. I'm fairly certain I have most of the dust removed.
1. New thermostat. No change. I even tried 'jumping' the thermostat circuit (with a PC motherboard/drive jumper) to eliminate any heat issues and it makes no difference.
2. Tried running a fan on the back of the boards/components with the back cover off while running the TV. Fan was blowing air INTO the unit, not venting per se. This did however seem to keep it MUCH cooler. Seemed ONCE to have run a bit longer than normal, but still same issues. Screen black with audio for a few seconds, then powers off with 3 LED's on front.
3. Connected laptop to VGA port in attempt to bypass one of the boards (analog or digital...not sure yet because I'm still learning), but it didn't matter because it did the same thing.
4. ETA: I tried the lamp cover blue switch issue as well. I even jumped this as well; but it provided no change.
I'm certain it's not the thermostat or lamp cover switch issues that are common.
Got into 'setup' mode or whatever you call it by hitting MUTE, 1,8,2 power.
Lamp said 8600 hours and guy I got the TV from said he's never changed it. So that's on order as of tonight.
(cheaper first, rigth?)
Performed a reset on the lamp hours and a general TV reset. No change other than I had to specify the source back to component 2 after doing this. No change. Same exact results.
NOW.....the other night I was trying some different angles for cooling with the fan and upon turning it on, my screen (for the very first time) displayed a 'grid' of white boxes and the football game behind it. These boxes weren't 'full' but more were symmetrical across the entire screen.
They were LIKE THIS: gadgetbench.com/hlpnotes/pixel_mapping_off.gif
NOT like this: fixya.com/uploads/Images/CC064CB.jpg
The difference is they weren't solid boxes as in first photo. They were "Pixelated".
However, it only did this twice and after I unplugged the power it hasn't done it since, but honestly at 10 minutes a pop before shutdown and another failed test, I haven't had the TV running much.
I'm sure it means I have an issue that's manifesting, but I thought it would be prudent to the troubleshooting notes.
So where I'm at is this;
I don't know if this is a power supply issue, a ballast issue, a lamp issue (certainly won't fix the white boxes), or some other issue such as the light engine, color wheel (doubt this) or the chip issue that some where fixing by having the soldering 'baked' by the guy in Michigan (yes, I read that entire 30 page thread tonight).
I think that's all I can offer for now. Feel free to ask questions, but I could sure use some assistance getting it resolved.