DMD Board REPAIRED!!!

[lowaek]

So first off, I haven't posted a topic before, and just registered here today. I would like to thank everyone for all the postings here as I have repaired my samsung DLP 56' TV. (model hl-r5678w). I had the dreaded "white flash" syndrome that seems to be a common problem with a lot of these sets. I don't know a lot about DLP's, so I decided to take it upon myself to do the repair, as I know electronics pretty well, and hopefully pass some information to help someone else out. The first thing I looked at was the lamp, which seemed to be fine, no flicker, etc. The 2nd thing I moved to was the ballast, and was hoping for an easy fix. I just happened to have another Samsung here with the same ballast, so I switched them out, and same problem. I then moved onto the color wheel, did a full inspection, cleaned the wheel, and even put a couple drops of electrical oil where it spins hoping this would fix it, same problem. I knew I had to move onto the DMD board. I removed the board, cleaned the board with 91% rubbing alcohol, dried it really good with a hairdryer, and put it back in. It worked perfect for about 45 minutes, and then the flash came back. So I knew the problem was a cold solder connection somewhere on the board, but I had NO idea where. I gave up for the night and started right away as soon as I got up today. I took the board back out, and this time I decided to take a little different approach. The first thing I did was remove the processor from the board, and then took a big bowl of HOT soapy water, and drenched the entire board. I then took a large scrub brush to clean the entire board. I then rinsed it off extremely well, and drenched the whole thing, both sides with 91% rubbing alcohol. I then took the hairdryer to the board for a good hour running on high. After that, I wrapped the entire board in aluminum foil, covering everything except the plastic ports and the plug in for the DVI cable( I cut out holes in the aluminum foil for these plug ins). I preheated the oven to 450 degrees, and set the board in the oven for 45 minutes. I figured if it was a cold solder connection, then I would hopefully re-flow the solder on the board. I took the board out of the oven and let it cool down (extremely hot). I took off the foil, put the whole TV back together, and it has been working flawlessly for 7 hours now, running nonstop. I don't know if this will work for everyone, and I could be back in the same boat tomorrow, all I know is right now, its working great. I will keep you updated in the next few days to let everyone know if I encounter any problems. Thank you again for all the great posts, as without this site, I don't think I could of figured it out.

Lowaek

[Technician]

[lowaek]

You are welcome! As of today (June 21) the TV is still working perfectly! It gets used around 4-8 hours a day and no problems what so ever!

[lowaek]

Still working good!! Hopefully its fixed for good!!