Samsung Pot Tweak

From Xbox-Linux

acelroc (Copied from XBox-Scene Fourums (http://forums.xbox-scene.com/index.php?showtopic=161728))

ONLY perform this tweak if your Samsung drive is almost dead or won't read most media (rather rare).

There are already good tutorials detailing the disassembly and removal of the DVD drive (http://www.llamma.com/xbox/Repairs/Samsung_DVD_Complete_Disassembly.htm), so I won't bore you with those details. Once you have the drive removed, remove the four screws on the bottom of the drive and remove the bottom cover the screws were securing. Your drive should look like this:

samsung.gif

You can see the laser unit, and the two potentiometers are located for easy access. I couldn't find any posts or tutorials regarding the Samsung POTs, so I wasn't sure which was the pickup I should adjust. I scraped some of the epoxy and measured the resistance of each POT. One was at about 2.3K ohms and the other was at about 960 ohms. I decided to adjust the POT that was at 960 and see the effect, then I would try the other if I saw no improvement. As mentioned in the existing POT tuts, be very careful scaping off the epoxy holding the POT screws in place. I personally removed my whole laser and did it under a microscope with an exacto tip, but that is because I had the scope handy! The potentiometes are very touchy and sometimes jump huge amounts when you adjust them. It took some careful tweaking, but I got the setting to 865 ohms, which I thought I would try. The POT I adjusted is indicated in this picture, and I was measuring the resistance between the POT terminals labelled 1 and 3.

sam_poten.gif

I reassembled and tested the unit, and I couldn't be happier. The performance difference is like night and day! I can load all the originals I try, and the XBOX demo discs that I could NEVER get to load, load right up without a hitch. If you have the steady hand and proper equipment, I'd measure the POT resistance while making the adjustment with a plastic screwdriver. A metal screwdriver will throw off the resistance reading because of the design of the POT. Don't bother trying to measure the POT while adjusting if you only have a metal screwdriver handy. Just go through trial and error

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