Audio Systems: Pioneer Radio/MCD Problem, pioneer fh p85, ribbon cables

Question
If it helps, here is a description / numbers on the boards in the system:

CNP4169 is the lower board. On this board is the IP-bus (multi-cd), Cassette, am/fm tuner (all three of these exibit the hissing problem). The front panel buttons/display connect to this board and work fine. There are 2 ribbon cables going to the other board (described below). One cable (CN1020) is wide double sided, located close to IC PA2024A (IC701). The other cable (CN1010) is a small single sided cable located away from everything.

CNP4168 is where the speakers and power connects, along with the single cd player (which works great). The small cable from the other board connects close to what looks like the main amp (IC1501) at CN401.
The Large cable is connected to this board at CN1701.

Thanks!!!

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Followup To
Question -
The numbers on the sticker are:
Pioneer FH-P85 March 1996 and the serial number. No ford sticker.

I was noticing that all of the stuff that is making the loud hiss instead of sound is on the same board (radio/cassette/MCD). I found what I think may be the pre-amp. It is part number PA2024A, with 5-6 capacitors around it, with the output going to a ribbon cable to the other board (with the main amp and single CD).

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Followup To
Question -
Thanks.. I will check the preamp section... BTW, when I touch the pins on the chip labeled YSF224B-M the problem either goes away or minimizes.

As for the manual, it is not downloadable. Pioneer site has never heard of the FH-p85.

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Followup To
Question -
I have a 1997 explorer with a pioneer FH-p85 head unit (am/fm/cd/MCD changer).
While listening to the am/fm radio or the MCD changer, the unit starts playing very loud 'static', then makes some squeeky noises and goes to no volume. The single CD and tape functions work great. If I power off the unit for a few minutes, the am/fm and MCD work, but soon exibit the same problem.
Pioneer has been no help, since I can't find any acknowledgment that the unit even existed on their web site (except that they sell a manual for the unit)

Any ideas? Also, any ideas on how to update the station list on the ID logic? (Don't have the manual)

Thanks...
Bill
Answer -
Bill,
Most likely something is failing in the audio preamp section for the radio section. It sounds like a capacitor in the preamp section is failing causing the strange noise/static. The problem may also be related to a defective solder connection. As for the manual, you should be able to down load the owners manual from Pioneer.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net
Answer -
Bill,
If the head unit was made for Ford and installed as original equipment, Pioneer won't have the info. If possible please give me all the numbers off the sticker on the stereo.

TOM,
T&D ELECTRONICS
Answer -
Bill,
I will do some research on the noise problem and see if I can locate any service info for this model.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net


Answer
Bill,
You will need to test all the caps in the preamp area. The best way would be to use an oscope to look at the inputs and outputs of the caps. I don't have the service manual for this model, however I did locate a service manual from one of my distributors. The cost of the service manual is $35

TOM,
T&D ELECTRONICS