Hello there all, I'm new to this forum, but have followed the Samsung DMD discussion for a while now.
To give you some background, i bought a Samsung HLP4663W DLP set off of craigslist for an absolutely incredible deal. The guy that i bought it from said he had a tech look at it and they diagnosed it as needing a DMD BOARD, not just the chip. So i get the tv and start fiddling around inside of it. The lamp light was flashing on the tv any time it was turned on, so I thought "start with the easy things, and work your way to the tough things." So i ordered a new lamp off of eBay. After installing the new lamp, it still didn't turn on. So I began some more research into what my problem could possibly be. So i decided to test each major component (color wheel, lamp, ballast) one by one. Here's how i did it.
To test the color wheel, I took the color wheel out of the unit by following the instructions in the service manual. I found that the color wheel was "bad", because any time I would try to turn it, it would make a horrid screeching noise. So i took the actual WHEEL out of it's metal housing, and separated the two parts of the wheel, that is, the actual clear colored "wheel" part, and the "motor" part. It took some force to get them apart, because they are held together by an airtight vacuum. However, upon inspection, there is actually no motor that spins the wheel. It is performed by what i assume is an electromagnet. Therefore the wheel spins without any real connection to its "motor". So i separated the pieces, and then lubed it up with some WD40. It then spun freely without screeching. Then i re-assembled the pieces and took the brown ribbon cable, this is the cable with 4 contacts on it, and taped it down to my workbench, with the contacts facing up. I then took a AAA battery and attached some leads to the positive and the negative side. Then, i attached the leads to the contacts on the ribbon cable, i am not sure which contacts, but i remember it working with a few different combinations. Then, to my amazement, the wheel started twitching! if i tapped the leads repeatedly onto the contacts, it would even spin! This led me to believe that my color wheel was now fixed, and not bad. I then re-installed the wheel into its housing, and re-installed it into my unit.
I then set out to see if my lamp or ballast was bad. To do this it took quite a long time of fidgeting and poking and prodding. What i discovered was this.
If i bridged a certain connection on the DMD, the lamp would fire up! This connection was the two leftmost pins on the connector that went from the DMD to the ballast. I bridged them with a piece of solder. Then, when i went to turn the tv on, VOILA! The lamp came on! This told me that both my lamp and my ballast were fine. The color wheel still did not spin, but due to my previous diagnosis, i still knew it was good.
So what does all of this tell me? That the previous diagnosis of the DMD board was correct. The board is not allowing the color wheel to spin up, firing the lamp, or engaging the DMD chip.
Hopefully this can help some of you narrow your problems down! Because as far as i have seen, this is one of the only ways i have found to be sure if certain components are bad!
Thanks for reading.
To give you some background, i bought a Samsung HLP4663W DLP set off of craigslist for an absolutely incredible deal. The guy that i bought it from said he had a tech look at it and they diagnosed it as needing a DMD BOARD, not just the chip. So i get the tv and start fiddling around inside of it. The lamp light was flashing on the tv any time it was turned on, so I thought "start with the easy things, and work your way to the tough things." So i ordered a new lamp off of eBay. After installing the new lamp, it still didn't turn on. So I began some more research into what my problem could possibly be. So i decided to test each major component (color wheel, lamp, ballast) one by one. Here's how i did it.
To test the color wheel, I took the color wheel out of the unit by following the instructions in the service manual. I found that the color wheel was "bad", because any time I would try to turn it, it would make a horrid screeching noise. So i took the actual WHEEL out of it's metal housing, and separated the two parts of the wheel, that is, the actual clear colored "wheel" part, and the "motor" part. It took some force to get them apart, because they are held together by an airtight vacuum. However, upon inspection, there is actually no motor that spins the wheel. It is performed by what i assume is an electromagnet. Therefore the wheel spins without any real connection to its "motor". So i separated the pieces, and then lubed it up with some WD40. It then spun freely without screeching. Then i re-assembled the pieces and took the brown ribbon cable, this is the cable with 4 contacts on it, and taped it down to my workbench, with the contacts facing up. I then took a AAA battery and attached some leads to the positive and the negative side. Then, i attached the leads to the contacts on the ribbon cable, i am not sure which contacts, but i remember it working with a few different combinations. Then, to my amazement, the wheel started twitching! if i tapped the leads repeatedly onto the contacts, it would even spin! This led me to believe that my color wheel was now fixed, and not bad. I then re-installed the wheel into its housing, and re-installed it into my unit.
I then set out to see if my lamp or ballast was bad. To do this it took quite a long time of fidgeting and poking and prodding. What i discovered was this.
If i bridged a certain connection on the DMD, the lamp would fire up! This connection was the two leftmost pins on the connector that went from the DMD to the ballast. I bridged them with a piece of solder. Then, when i went to turn the tv on, VOILA! The lamp came on! This told me that both my lamp and my ballast were fine. The color wheel still did not spin, but due to my previous diagnosis, i still knew it was good.
So what does all of this tell me? That the previous diagnosis of the DMD board was correct. The board is not allowing the color wheel to spin up, firing the lamp, or engaging the DMD chip.
Hopefully this can help some of you narrow your problems down! Because as far as i have seen, this is one of the only ways i have found to be sure if certain components are bad!
Thanks for reading.
