"Mark D. Zacharias" wrote in message
. com...
ampdoc wrote:
"David Farber" wrote in message
news:Kj_ug.9123$Oj.2015@trnddc05...
That's about as an encouraging a response as I could have hoped for.
I'll order the uP and expect a full recovery.

Regards.

--
David Farber
David Farber's Service Center
L.A., CA

wrote in message
ups.com...
Something on the DSP board is locking up the I2C data bus lines.
Pretty common problem during storm season on similar Pioneer models
a several years ago.
Had my own DSP ic fail in this way. $35 flat pack ic fixed it.

David

David Farber wrote:
This Pioneer VSX-D908S analog/digital receiver will not pass any
audio as long as the dsp board is plugged into the unit.

First I'll explain what works with this set. With the dsp board
removed, all analog input functions work as long as you select the
direct mode. The direct mode bypasses the digital board
completely. For example, if you've selected CD direct (analog) for
the source, there is an electronic mode switch, located on the
main control board, which selects between dsp, direct, or 5.1.
This switch will select the direct mode correctly and pass the
audio signal. What doesn't work is if you plug in the dsp board,
the audio does not pass through the same analog/digital mode selector
on the
main control board even in direct (analog) mode. The dsp board is
quite complex but there is a uP there that communicates with the
control board's uP. Now here's where I have, hopefully, an easy
question. Two of the pins on the uP of the dsp board are labeled
Xin and Xout and they have no signal. On the uP of the control
board, there is good signal at the uP on the Xin and Xout
terminals. Can I generalize that any uP that has two terminals
labeled Xin and Xout should have a continuous running clock signal
on these two terminals? Also, would the uP itself be the most
likely failure to cause this symptom? By the way, I spent a fair
amount
of time removing
all the
boards and soldering numerous bad connections.

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA





I think I remember these units, it's not the micro or DSP, it's the
EEPROM. IC9374 I believe. Pain in the butt to solder in, very fine
lead spacing even for a SMD. There was a problem with that unit, the
EEPROM types were changed, I can't remember if they went from FLASH
to MASK type or the other way around, but changing it usually fixed
the problem. In some lucky cases you could just resolder IC9374. If
you get the newer type EEPROM there are 2 jumpers (Zero ohm surface
mt resistors) that have to be moved for the new type to work, unless
this unit has been repaired before.
Hope this helps.

Jammy

I believe you are thinking of the VSX-24, 26, 27 etc models. Different
model
entirely.

Mark Z.



Hi Mark,

The VSX-D908S *does* have that IC9374 EEPROM with the fine lead spacing.
Unless you meant that the VSX-D908S didn't have a common failure of the
EEPROM whereas the VSX-24, 26, and 27 did. My question remains whether this
could be causing the uP to have problems.

Thanks for your reply.
--
David Farber
David Farber's Service Center
L.A., CA