Just picked up this low-end player for uber cheap because I lost hope in my other player I've been on/off fixing for years. I tested it when I bought it with a random cd lying around, and it played fine. However, when I got home and tried to actually play a LD, it spins up like it should, clicks a few times irregularly, and this "E-04" pops on the front screen, and the disc winds down. From what I see, it's a clamp problem, mostly caused by improper handling. I found this thing sitting sideways, and has been for years probably, so that holds true. What I can't find is how to fix it. Is it some sort of broken part, a misaligned part, or something I can't see. I've been trying to get into LDs for years and I just can't seem to catch a break on players...

[GLOBAL] List of Pioneer Error Codes

I don't think it's a clap issue (that would be a U1 error or a ?3 one).

E4 = Slider error @ Disc sense checkpoint

The laser bock doesn't find the disc?

Julien

Looks like you were right about the slider, but what could I do to fix it? The laser transport seems to move fine, and plays CDs. I took the cover off, and it appears that the laser checks for LDs, moves up and down, the moves closer to the center for CDs. I tried lubing the rails on the laser, too, but to no avail. Also tried a lens cleaner CD, and nothing. I assume the laser is going up and down, searching for the disc but can't find it? Maybe?

Is it possible that this issue is just a stretched loading belt? A loose belt would probably make clamping an LD more difficult vs. a CD.

If it reads a CD OK then you have issues in the LD playback electronics. In CD mode players turn off the video circuitry and track the disc using CD playback circuitry. When an LD is played it turns on the LD playback circuitry and uses that to track the disc. Probably lost an electrolytic cap on the main board.