Well, it finally happened to me. About a month ago, the DVD drive on my Panasonic DMR-EH75 suddenly died after years of reliable service. The machine couldn't even tell if there was a disc in the drive or not. The noises the drive was making indicated that the problem was with the optical pickup. I saw that there was someone selling the optical pickup units (3331A) on eBay, so I bought one. I had opened up the DVD drive for spindle cleaning several times, so I figured I would see if I could replace the pickup myself. And indeed, I swapped the old and new pickups without any problems. I was very careful to put everything back the way it had been. When I powered up the machine, the drive worked, although it still occasionally made those sickly noises.
Two days later, the DVD drive stopped working again. The machine now says "no read" for all discs. I cleaned the spindle and laser (a couple times actually), but that didn't help.
Did I fry the new pickup already? Is there any chance it could have been defective? What can I do now?
I've heard that in the EH75s, the DVD drive is supposed to be replaced together with the PCB board. However, some users (Mickinct) have reported success in just replacing the optical pickup. There is also supposed to be some sort of realignment procedure when only the pickup is replaced; I have no idea what that procedure is though.