Pioneer PD 4700

[henri_85]

Hi everyone,

A friend gave me his old and faulty Pioneer PD4700 CD player. I would like to fix it, even if it may not be an exceptional quality player. I'm curious to see if it is possible to do so with a Pioneer, as I'm not used to that brand at all. The player can't play a disc more than 4 or 5 minutes without "crashing". I've seen (using the last track of a 79min CD) that focus and radial corrections seem to be correct, even when the fault is present (it doesn't last a lot though, the player stops/gives up very quickly when the fault appears). But immediately (more than 5 seconds) after the crash, you can restart to play the disc, but it won't work more than 2 or 3 minutes, and even less if the player is hot.
I've also noticed it works much better (about 20 minutes) when the temperature is cold. Yet the temp is under 10°C in the room in which I'm used to tinker .
I think of changing the LA6520 IC, which seems to be the mechanism driver. Actually it's the IC which is the hottest, even if it doesn't mean anything...
So, any help and advice would be welcome. I would be glad to know if that type of player can perform self-tests/checks.
Thanks,

Henri

[tubenut]

I think this amy have been the first cd player I owned.
In comparison to the Philips machines of it's day (like CDD600/610/620/30) it sounded very vibrant and bubbly but with a rasp in the tops. This was before I started tinkering with CDPs though.

I suspect a dodgy laser unit rather then an IC though.

[henri_85]

Thank you for your reply.
As the Pioneer is not a Philips , I also feared a common laser fault. That's a shame. Then, if I have time and an opportunity, I'll buy the cheap IC and see what happens.

And now back to CDM1, CDM2 and CDM12 !

Henri