Pioneer PD-8700 player with Dim display, anyone know a fix

[Paul-H]

Hi all



Hope this is the correct section to ask this question. (Perhaps a Mod could move it if not)

I have an elderly Pioneer PD-8700 CD player, it does not get a lot of use as its a backup player used when I encounter a disc my usual player has issues with, although it works fine I have noticed the Blue display is a lot dimmer than it used to be. Is this an age related known issue with these players or is there a known fix to bring back the brightness levels.

I had a look through the service manual, hoping to find a brightness pot, but no such luck.

Anyone got any thoughts on a fix for this model.

Thanks in advance for any help.

Paul

[JimC]

Service Manual available on Elektrotanya FOC. ( https://elektrotanya.com/pioneer_pd31_pd7700_pd8700.pdf/download.html#dl )

Probably the Display Tube itself.

But you could check there is something like 2 to 6(?) Volts AC across the two pins at either end of the Display, Labelled in the Manual as AC1 and AC2
Also check the Zener Diode D54, MTZJ18B/C. I am going to guess that's an 18 Volt Zener 'reversed' so AC1 and AC2 will have a DC Bias of -ve 18 Volts WRT 0.Volts
Check C52 also, this may well have drifted in value over time.

If these are OK then I'm afraid it'll be the Display tube. Look for a donor player with a good display.

[Lawrence001]

I had a rebadged Pioneer stable platter CDP and it had a very dim display. I've seen many similar ones so it's just the aging of the display I think.

[Firebottle]

Likely there is a thin film of dust on the display and/or the back of the filter window.

Cleaning these improves things slightly.