or Connect
AVS › AVS Forum › Display Devices › Rear Projection Units › Samsung HLR5678W DLP doing all sorts of crazy things
New Posts  All Forums:Forum Nav:

Samsung HLR5678W DLP doing all sorts of crazy things

post #1 of 5
Thread Starter 
I should preface this by saying that I'm a pretty technical person - I've built, repaired, or otherwise assembled/disassembled hundreds of computers in my life, but this is my first time with a TV. I'm fully comfortable taking this TV apart, but I'd really prefer if it was just one time - due to the timing issues involved, etc., cracking this thing open a half dozen times (or leaving it open for a week) isn't really an option.

My parents have a Samsung HLR5678W 56" DLP TV. They bought it brand new, have never had any problems with it, never had to change the lamp, etc. A few months ago, it started making a whining noise on startup, which made me think it could be the fans or color wheel (as far as I know, the only moving parts). The noise came and went, and we were all busy at that time, so we never really did anything about it.

About a month ago, the TV started developing fuzzy blue horizontal lines. They would "attach" to something on the screen - someone's cheek, for example - and follow it as it moved up or down the screen. The line itself would be very thin, and would expand to the same size as the object it was following - it looked kind of like a stretched blue shadow with a thin line attached. I didn't get a picture of this, unfortunately.

Shortly after that, the colors started to mess up, and sometimes looked blocky (see pictures 1, 2, & 3). Sometimes it would all look blue, sometimes it was all very green. This made me think color wheel, too, so I got ready to order one. Then it went from annoying to all but unusable.

Then something strange happened, that I just can't see being caused by the color wheel. It looks like the resolution changed - the picture is way too big, cut off, and not proportional (see picture 4). Everything is squeezed in horizontally, but vertically, the bottom half of the picture is cut off. I plugged my laptop in, since that's the only way you can really change the resolution on the TV, but even when I set it to 1080p (also in picture 4), the problem was still there.

After reading some more online, I figured out that leaving the TV unplugged for 30+ minutes before using it would reset something inside, and when you plugged it in and turned it on, the resolution would be right, the blocks would be gone, and the color would (usually) be right. The blue lines were back (still there? I couldn't tell if they were gone when the color & resolution were wrong), but the TV was once again usable.

Then unplugging the TV stopped working consistently. You could leave it unplugged all night, and the next day the resolution and colors would still be all wrong. That comes and goes right now.

Finally, as of Friday night, it's now doing whatever you'd call the thing that's going on in pictures 5 & 6. A big line across the screen, and everything below that line is very much the wrong color.

All of these problems occur on all inputs, on all channels, with all picture settings - everything in the menu that could affect it, I've tried.

I'm at a loss at this point. Like I said, I'm not afraid to open this thing up, and I'll do most anything short of soldering (not my strong suit), I just need to know what I'm looking to replace/repair, and/or if there's so much broken that it's not worth fixing. We just bought this thing a few years ago, and their last set lasted 27 years (we all knew that wouldn't happen this time around), so they're not really looking forward to paying $700 for a repairman or $1000 for a new set. Any suggestions or insights would be greatly appreciated.
post #2 of 5
You may find one of the fans stopped, and is allowing the tv to over heat.

Once you open it to clean it out, you can replace the fan... or with a bit of luck the fan is brushless. Taking off the label and opening the small round service cover on the fan, will allow you to use TV tuner cleaner & lubricant (rat shack) to loosen and clean out the fan for proper function. Dust build up has stopped the fan from rotating.

It looks like the main board is going. Dust build up and heat may have damaged the processor. Even cleaning the main board thoroughly will not revive functionality lost.

If you replace the main board check the power supply.

I don't trust Samsung power supplies on DLP tvs. It is always good to make sure the power supply has proper voltages for the main board.

All DLP tvs need a proper cleaning time to time. I can get by with a 2 year time frame at the longest.
Edited by Low Tech - 8/6/12 at 7:21am
post #3 of 5
Thread Starter 
Excellent thought on the fan. Is that something I could test by pointing a powerful fan at (or away from) the back of the TV, where it's vented? Or am I just messing up the airflow then?

I'll check the main board, and check the prices on replacements. As far as the power supply, what I'm testing for is that it's providing the proper voltages at its contact points with the main board? Can I find those voltages in the service manual?

Thanks for all your help - it's the most I've gotten anywhere, by far.
post #4 of 5
Thread Starter 
Ok, just one bump, to see if anybody else can answer anything from my first or last post. I've gotten in touch with a repair company, whose diagnostic fee is at least reasonable. Maybe I can let them diagnose and then repair it myself, who knows.
post #5 of 5
I would recommend spending a couple of bucks on a service manual for the TV (search for a downloadable version) and study the different boards and flow charts involved. It might be worth the small investment if it gives you a clue about how to proceed. My best guess is mainboard, but before replacing that I would want to eliminate other possibilities.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Rear Projection Units
AVS › AVS Forum › Display Devices › Rear Projection Units › Samsung HLR5678W DLP doing all sorts of crazy things