Originally posted by chunkhead:

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I'm sure many of you have gotten the dreaded "Dirty Disk" error or your drive has completely stopped reading discs. Well, before you go and throw out that drive or replace the laser, try tweaking the pot within the drive. The "Pot" is the drives calibration and is set from the factory, however, it may have become un-calibrated, or in most cases does not allow you to read certain types of discs.

This tutorial is ONLY for the Phillips 6035\21 drive, I will add in a picture of the Phillips 6011\21 also as this technique works for that as well. This can also be successfully used with the Thomson drive, but different settings will apply. I will give these later.

Ok, if one or more of the following symtoms describe your problem, then "Pot Tweaking" can help you.

* Dirty Disc Error
* DVD Wont read discs
* DVD Wont read certain discs (DVD-R, CD-R, etc.)

There is already a few guides available on the net for this, but I found that they were very vague and not much use to the average person.

Ok, you will need:

* Small screwdriver
* Multimeter
* Patience

So, for the purpose of this exercise I will assume you can open the Xbox. If not do a quick search on the net to find out how!

1) Power on your Xbox with the case open and press the button to open your drive. With the drive open, unplug the power cord, this will keep your drive tray out.

2) Remove the 4 screws from the top of the DVD-ROM, there is no need to remove the drive from the console at any stage! The top should come off easily.

3) Locate the "Pot", just like in the picture. The "Pot" is actually a screw which is known as a Potentiometer, hence "Pot".



4) Now, with multimeter in hand, set it to 2000 ohms, just like the picture.


Touch one end on the left leg of the "Pot" (Top Arrow) and the other on the top of the screw (Bottom Arrow. You should get a reading. For examples sake, mine read 1014 ohms.

5) Now, EVER so slightly turn the screw clockwise and re-test with the multimeter. I can't stress enough how little you need to move the screw, when you turn it and re-test you'll understand.

6) Ok, what you're looking at doing is changing the resistance to a level where it happily reads disks. Move down in increments of about 100 ohms, but no less then 500 ohms as any less will fry your laser. The actual reading which will work for each drive will vary, so this where the patience kicks in.

7) In order to test your new settings, just replace the top cover of the DVD drive (no need to put the screws back in yet) and test with a disc that normally wont read. My experience found that I got no joy until 564 ohms, where it started to read the DVD-R, but the drive was very noisy and then froze on loading a game. I tweaked it back up in as small a increments as humanly possible and the drive operated flawlessly at 609 ohms!!!

8) Goodluck!!!



PHILLIPS 6035\21 No less then 500 ohms

PHILLIPS 6011\21 No less then 500 ohms
http://forums.llamma.com/viewtopic.php?t=111
THOMPSON No less then 800 ohms
http://www.llamma.com/xbox/Repairs/thompson_potentiometer.htm

SAMSUNG Pot




I hope this helps someone else out there, comments welcome!!!

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