Laptop DVD drive troubleshooting

Guest post from DJ:

Platform: 

Dell Vostro 1400

Windows XP SP3

Problem: For over a year the CD/DVD RW player did not perform properly. Jittery playback of Audio CD and most commercial DVD discs were not read. Writing was producing errors and most DVD R blanks were not recognized. 

Analysis 1: Drive lens problem. Cleaned it a couple of times - No positive impact

Analysis 2: Drive hardware problem. - Result out of laziness did not bother to fix and planned to buy external USB drive.

Analysis 3: (After over an year of sadness and lack of enthusiasm). Lens and hardware at fault. 

Took out my camera lens cleaner kit and carefully cleaned the lens. Still there was jitter. But all discs and DVD's were recognized. This gave me hope. Also I noticed that during DVD playback the computer response was sluggish. This prompted to think of DMA. In Device manager I found that the mode was sett to PIO and DMA was not an option. This was quite strange. Out of curiosity I checked the Dell website for any available updates. 

There was a firmware update available for the DVD drive. Carried out firmware upgrade for the DVD drive. Voila - Now it works like a charm. All DVD's are playing smoothly. Have not yet tried burning any discs yet.

I still cannot figure out how the firmware got corrupted - the DVD drive used to work fine earlier!