Samsung DLP tv HLM617W color wheel

Hi. Got a Samsung HLM617W dlp set here. Runs good for 10 minutes or so, then picture begins breaking up, with a corresponding uneven sound from color wheel motor housing. I reckon color wheel motor is the problem, but figured to see if any of you guys have had similar issues with this model before. Samsung parts place says they sell many of the color wheels. Sound right? Just trying to be sure before I order parts, and it is possible it could be mirror chip. All fans are good and running. Bulb is strong and not flickering. It affects all parts of picture, including menu.

Danny

I don't mean the scan, but the sync pulses from the control sending the different color information to the dlp.

I was thinking the scan as it relates to scanning between red, green, and blue.

FYI color wheel motors do commonly have problems, but I have seen control problems exhibit similar issues.

The color wheel and DLP/DMD chip are slaves to the incoming sync. So, yes, could be the motor but could also be a video/sync issue. It's not likely the DMD chip itself.

If you can locate the sync pulses driving the color wheel servo, start there. If the motor isn't expensive, then, sure, try a replacement or swap one in from another unit.

--- sam | Sci.Electronics.Repair FAQ:

Repair | Main Table of Contents:

+Lasers | Sam's Laser FAQ: | Mirror Sites:

Important: Anything sent to the email address in the message header above is ignored unless my full name is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

What I was going to try and do is this -- get the color wheel out of the way of the light path and see if set runs stable as a black and white. I know the high speed of this wheel, near 11000 rpm, will require great care in this plan. Samsung gets like 130 for the wheel motor. Lady has had no end of trouble with set and Samsung will no longer warranty it, therefore I have it to look into. Other than 2 bulbs and a new ballast I don't know what else has been done to it. She wants a firm estimate of repairs, so she can decide then. In other words, I must be dead on before I spends her money. Perhaps set will run with color wheel unpluged and out of the way. I should then be able to tell if it is a sync or mechanical problem with color wheel moved, at any rate.

Danny

way

of

it

decide

be

No need to take it out of the way, just unplug it, the screen will be all one color but otherwise no different than it removed entirely. The unit may wait until the wheel is spun up before doing anything though.

Yeah, I found that out today. Demounted wheel and bolted to frame to keep it from wandering about. It is distinctly noisy when it spins up. You are right, lamp won't come on with color wheel removed, even with cables connected. Guess I should remount properly and make sure nothing else has gone awry. These DLP sets are new to me so I am learning their ins and outs.

Danny

Disregard my last post. I had forgotten to plug ballast power back in. Light works better with electricity attached.

Latest DLP experiments and results --

Samsung DLP set will run fine with color wheel mounted outside of light tunnel, and shows in black and white, but will not run if color wheel motor is unplugged.

After this test, set runs and picture very jittery as before. Took color wheel out of motor mount. I then see a small infrared sensor, like used in vcrs. It had some dust on it. I cleaned away the dust, and gently dusted the wheel, but it looked clean anyway. I remounted wheel to frame and restarted --

At this point picture is perfect, in black and white. I allowed to run some hours while I did other work and errands. Stable as can be. I will remount in light tunnel tomorrow and allow to run the day. If solid, will reassemble and see how she does.

Cheers, Danny