[Joe Demuth]

I have a Samsung HL-S4666W that has been working great for 15 months, but recently small white specs have started to appear on the screen and multiply in number every time the TV is turned on.


Samsung tech support says it sounds like the DMD chip is failing.


I have found a DMD board (ASSY DMD BOARD P, part #BP96-01580A) that is the replacement, and some posts say the DMD board is like a motherboard in a PC. Also learned that this is expensive for a service person to repair - almost the cost of a new unit !!!!


Question is:

1- how easy is it to replace this board for a technically skilled person?

2- how easy is it to get to the DMD board ?

3- are there any optical aleignment needed after installing this board?

4 -are there many settings or adjustments on the board that need to be made once installed?

5- any photos or schematics online of this board and its locations in the unit?


Note: the online manual shows photos for replacing the lamp, and off to the right side of the lamp cover is what looks to be a vertically mounted board. Is this the DMD board ??

 

[Bobarino]

I too would like to know this as my 2 yr old 4676 developed the first bright white spot last weekend.


Looks like lots of other folks on these forums are starting to have the same problem with their DLPs.


I can't believe that Samsung would push DLP so hard if they knew the DMD would start to fail after only a couple of years on average.


I am very dissapointed to spend so much money initially, have a failure after 2 yrs, and face the prospect of replacing a DMD board that costs almost as much as a brand new TV.

 

[mes444]

I think you would be making a mistake to spend the money to replace the DMD board, it is like the motherboard of the tv and in my opinion, adding a new main board to interface with all the older parts in the tv now might result in other malfunctions, like a new motor in an old car.


Samsung DLP is being phased out, soon there will probably be some excellent bargains on new ones. Or buying an LCD would also be a better idea than replacing such an expensive part.

 

[Joe Demuth]

The actual cost of the DMD board is not that bad - about 1/4 what I paid for the unit.


So if one could replace this and have everything work again, it would be worth it.


The big question is whether this messes up some other components. In principle, if the board is replaced it should have all the critical components to modulate the mirrors and light source.

 

[naseqp]

Facing the same problem.....just trying to decide to tackle the job.

if I replace this 24 month old tV it WILL NOT be a Samsung.

 

[Joe Demuth]

I purchased the DMD board that was cited by Samsung and Samsung parts for this model unit and went inside to replace the DMD board.


There was no problem in access or getting the current DMD out - pretty standard disassembly.


HOWEVER, it turns out that my unit has a DMD whose optical modulator works in reflection and has one side of the modulator completely blocked with a heat sink. The DMD board both Samsung and Samsung parts cite as the replacement has an optical modulator that works in the transmission mode, ie light passes thru it rather than being reflected. The circuit board numbers as well as the solder pins for the optical modulator on my board and the new board are very different eventhough all the size of the boards and the connectors are identical !


NOTE ADDED LATER- THE BOARD I RECEIVED DID NOT HAVE THE DMD PANEL ( THE MICRO-MIRROR ASSEMBLY IN IT) BUT IS STILL A DIFFERENT VERSION BOARD FROM WHAT IS IN THE NEW


Anybody hear of such problems ?!?!?!

Samsung doesnot even know the correct replacement part for their unit, or they have discontinued it and want to forget about it !

 

[PaulGo]



Quote:
Originally Posted by Joe Demuth /forum/post/15654228


I purchased the DMD board that was cited by Samsung and Samsung parts for this model unit and went inside to replace the DMD board.


There was no problem in access or getting the current DMD out - pretty standard disassembly.


HOWEVER, it turns out that my unit has a DMD whose optical modulator works in reflection and has one side of the modulator completely blocked with a heat sink. The DMD board both Samsung and Samsung parts cite as the replacement has an optical modulator that works in the transmission mode, ie light passes thru it rather than being reflected. The circuit board numbers as well as the solder pins for the optical modulator on my board and the new board are very different eventhough all the size of the boards and the connectors are identical !


Anybody hear of such problems ?!?!?!

Samsung doesnot even know the correct replacement part for their unit, or they have discontinued it and want to forget about it !

Was their a part number on the old DMD board? Many times you not only need the model number but the serial number or production run number to get the correct part. If you have an early production run you may have internal part from the previous years model. I would call Samsung technical support and try to speak to a level 2 technician to get this resolved.

 

[hammerdwn]



Quote:
Originally Posted by Joe Demuth /forum/post/15654228


I purchased the DMD board that was cited by Samsung and Samsung parts for this model unit and went inside to replace the DMD board...

What is your full model number and version number (found on sticker on SIDE of Tv)? If no version number then lamp code.

 

[Joe Demuth]

I did not fully remove the old board, and the only part number visable turned out to be the circuit board number- BP41-00281B. The number on the circuit board for the replacement DMD board as indicated by SamsungParts is BP-00270A. I did find that my old circuit board has been replaced by a new one BP94-02262A but were not available ?!


Good idea to talk to a level 2 technician. Thx

 

[Joe Demuth]

the model is HLS 4666WX/AA

Serial Number B19W3CMP30104P

Version: PB02


Again the incorrect DMD board Samsung Parts provided was BP96-01580A

 

[Joe Demuth]



Quote:
Originally Posted by PaulGo /forum/post/15654463


Was their a part number on the old DMD board? Many times you not only need the model number but the serial number or production run number to get the correct part. If you have an early production run you may have internal part from the previous years model. I would call Samsung technical support and try to speak to a level 2 technician to get this resolved.

I did not fully remove the old board, and the only part number visable turned out to be the circuit board number- BP41-00281B. The number on the circuit board for the replacement DMD board as indicated by SamsungParts is BP-00270A. I did find that my old circuit board has been replaced by a new one BP94-02262A but were not available ?!


Good idea to talk to a level 2 technician. Thx

 

[Joe Demuth]



Quote:
Originally Posted by hammerdwn /forum/post/15658191


What is your full model number and version number (found on sticker on SIDE of Tv)? If no version number then lamp code.

the model is HLS 4666WX/AA

Serial Number B19W3CMP30104P

Version: PB02


Again the incorrect DMD board Samsung Parts provided was BP96-01580A

 

[Quentin2]

Good luck getting this resolved, Joe. Please let us know how Samsung handles this. By selling you the wrong part I'd say they should be in this for the duration and should solve your problem one way or another. No doubt they should have spare parts for TVs they sell for at least a few years and it seems they don't. I'd say after a reasonable effort at replacing the part they should upgrade you to a newer set, maybe the current 50" DLP if yours is 46.

 

[PezJunkie]

Hopefully you've already gotten this resolved, but if not:


The DMD you need is BP96-01636A


Samsung service bulletin

Number: 06-DLP-E009

Date: Dec.11.2006


Applies to:

HLS**86WX/XAA, HLS**65WX/XAA, HLS**66WX/XAA


It says that they switched DMD boards & optic modules in October of 2006, and the two versions are completely incompatible (as you found out). So you have to check the Version listed on the side label...


Version PB01 = BP96-01580A

Version PB02 = BP96-01636A


(The lighting engine assemblies also have different part numbers, depending on version.)

 

[Joe Demuth]

Thank you for the information. This is useful.


I have gotten so much mis-information from Samsung, and various authorized Samsung agents, my repair efforts are on hold.


Samsung told me that the only DMD part available was the BP96-01580A.

( This board has alot of electronics on it and a hole and pin array to hold and heat sink the micro mirror array, ie light engine onto this chip. The light engine is not included on that board)


From the symptoms of my problems do you know what component is the source of my problem?


Again the problem is a somewhat uniform but random array of stationary white specs (now hundreds) on the screen which have been very gradually increasing over time with use.

 

[PezJunkie]

I have the exact same problem, stuck/dead pixels... mostly white, with a few black ones and a couple that flicker.


I'm beginning to fear that the DMD board isn't the problem, but the actual DLP chip. (The service manual stuff I have calls it the "DMD Panel", but I can't find that at any of the online parts places.)


I did find these by searching for "DLP" at samsungparts.com and/or partstore.com:


4719-001968 (samsungparts.com calls this TYPE A NON APERTU) Per the Service Bulletin, Type A = PB01 sets


4719-001981 - No description, possibly the Type X (PB02) part?

 

[Joe Demuth]

Well at least we have the same problem.


In considering what component may have failed, I have attempted to study how the DLP unit works. ( I have a strong EE background and alot of hands on experience with various electronics). So here's my version of how this works. Maybe this will help determine what needs to be fixed. (See http://electronics.howstuffworks.com/dlp1.htm ).


The Ti micro-mirrors ( DMD- digital micromirror device sometimes called the DLP chip) points various pixels of light to the screen via DDR CMOS SRAM elements under each mirror to be in an "on" or "off" position. This mirrror control signal is generated by a microprocessor which is likely on the DMD board since it must be close to the CMOS elements to get the morrors to respond fast enough. It takes 16 microseconds to create the conditions to "paint" an entire screen, ie all pixels for one moment of time that your eye sees ( ie integrated over like 0.15 of a second). I do not know how the microprocessor logic works - if if has a logical elements for each pixel on the screen or processes a row at a time and holds it in memory until the next refresh of that row is calculated. The later would seem more likely given the wide use of parallel processing in such microprocessors. This micorporcessor data output is coordinated with the color wheel to produce the right color for each pixel at the correct time.


If elements of the the micro-processor does nothing and remains in the "on" position, then the micro mirrors will shine all colors from the color wheel on the screen to produce a small white spot on the screen. If the mirror is in the "off" position there is light missing and there will be a small dark spot.


So the sort of light painting failure that we see, could arise from either a CMOS controller under the mirrors is not operating, or the microprocessor that controls the CMOS positions is not processing the signal for that pixel element. If the microprocessor works by processing and storing the on off information for each pixel, then what ever stores this information is messed up. Given the likely use of parallel processing in this processor, a failure of a storage element in this processor would create some kind of repeat pattern in the white spots that should be seem - but the white spots do appear random. (However, I really don't know for sure how the processor works.)


Solid state electronic failures usually are caused by over heating and a breakdown of the electrical materials. CMOS devices are more robust than other solid state technologies, but can still fail. Functional the DMD gets alot of heat and must dissapate it effectively. That's why the fan and huge heat sink fins are mounted to it. Any over-heating could eventually cause the CMOS devices (which tilt the mirrors) to fail or solder in the pins connectons on the board to melt One of the large chips on the DMD board also has a small heat sink and is likely the microprocessor. The fact that Samsung redesigned the pin contacts in the version 2 DMD boards implies they were having heating problems of the DMD and needed the DMD board to better dissipate some of the heat better as well.


So my money is not on the DMD board itself but on the DMD unit- the digital micromirror array that gets mounted on the DMD board. Note that the micro-mirror arrays were invented, promoted and liscenced by TI so they may have further information about them....???

 

[PezJunkie]

This service bulletin about the 2 different models also leads me to think the problem is the actual DLP chip and not the DMD board and/or its image processor.


It has a page for "How to distinguish DMD defect" with pictures of 4 examples. They are all horizontal or vertical lines that run the full length/width of the screen. None of them show the problem that we are having.


With both parts being $200 - $250, I can see now why Samsung says to just spend the $500 - $600 (after core refund) to replace the entire engine assembly and be done with it. (But damn it, I'm trying to be cheap here!)

 

[Joe Demuth]

Yes, I am trying to minimize costs as well and don't liked being ripped off, especially something I should be able to do myself. My unit was only 14 months and not used that much. After opening it up there was virtually no dust on the fan or boards.


I am having trouble with your nomenclature between DMD, DLP chip, etc.


The microprocessor that powers the micromirrors will be on the DMD board and is not part of the DMD (micro-mirror) assembly. The DMD fits onto the DMD board and has a huge heat sink on it with fins.


I can send you a photo of my screen to confirm with your and the manual's diagnisis if you privately send me your email address. Or I can figure out how to post it here after I process the image.


Thx for sharing the information !

 

[Joe Demuth]

pezjunkie


I have looked over the manual for your Samsung and the DMD board looks identical. It even has the blue paint on some of the circuit components whereas the other incorrect board Samsung recomended for my unit had red paint on them. The tricky thing seems to be the removal of the "DMD panel" - the assemby holding the micromirrors.


My hang up in full removal and access to the DMD panel was getting the whole assembly out. The dissassmbly manual shows how the whole optical table is removed. Based on this I can see why Samsung recomends the repair technicians replace the whole unit - DMD board, DMD panel (micromirrorrs) and color wheel - but the price is ridiculously high -$900 !!