Pioneer PD-F507 ...25 CD player which stops while in continuous play mode.

[Technomaniac]

Hi to all !  This player belongs to a local community FM radio station and is used as their overnight music player while all the volunteer workers are sleeping. I have had the unit in twice over about a month as the problem was intermmitently occuring. The first time in, I noticed that one of the arms that moves the selected disc to the playing position, was not moving too smoothly across the plastic chassis, as the raised section of chassis which acted as a friction reduction idea, had worn so that it no longer had a curved top to its section, but a flat area on the top of the curve, thus increasing the area of contact and consequently, the friction. I greased this arc of plastic with lithium grease, and replaced the loading belt as the few times I had it faltering, a little help in rotating the pulley just a bit further while loading would get the thing to run. But after a few weeks the unit came back in. The second time we found a more definite fault. Within the moving section there is a ribbon cable which is hard-wired to the (moving) PC board at one of its ends. I can't remember how many conductors in the cable, but let's say half a dozen. It is the type of ribbon cable which uses stranded conductors. The stripped end of the cable had been passed through the PC holes and soldered, and then a silicon-rubber sealant had been applied over the soldered connections. If this had been done on the OTHER side of the board it may have been useful in taking some strain. But anyway, one of the conductors (at the end of the row) had severed inside the hole in the fibre side of the PC board. Probably due to careless stripping. I also changed the TT motor as it sometimes wasn't starting. Spinning the disc by hand would get it away. They run them at low voltages and so they don't have much starting torque. One thing I haven't figured out.... One time with the original motor fitted, I spun it the wrong way to start it and it ran backwards ! I assumed at that point that it must have been a three phase motor like a VCR capstan motor, but when I gained access to it, found a little brush motor  as used in the average CD player. So how did it reverse direction?  Anyway, problem all solved.
Cheers !