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

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

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.
--

Xin and Xout are usually the terminals that connect the internal clock
generator to the external clock crystal, and you would normally expect to
see a continuous clock signal on at least one of them, but note that you
need to be using a x10 ( low capacitance ) probe on your scope to have any
hope of seeing a signal ( mostly ). On some clock generators, notably one
that runs a DSP chip in a Sony HC system, as soon as you come near the xtal
with even a low capacitance probe, the oscillator stops, never to restart
until you depower then repower to produce a reset to the DSP chip, so the
upshot of all this is that your DSP oscillator may possibly be running, and
nothing to do with the fault, and stops when you try to scope it. A better
indication may be if there is any activity on any of the other pins. However
this also does not give any certain proof of clock activity, as you may be
seeing shared-bus activity, originating elsewhere.

You may yet have xtal trouble though, particularly if it is a surface mount
genuine crystal, rather than a ceramic resonator, which tend to be more
robust and reliable. I have had a number of these xtals fail in a variety of
products. Sometimes, they are just reluctant to start up, and just removing
the xtal, and soldering it back in the other way about, is enough to get
them going. If the problem genuinely is clock related, then it is far more
likely to be the xtal, than the chip.
If it has been subject to storm activity though, then the chip becomes more
likely, as suggested by the other poster.

Arfa

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

"Arfa Daily" wrote in message
...

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.
--

Xin and Xout are usually the terminals that connect the internal clock
generator to the external clock crystal, and you would normally expect to
see a continuous clock signal on at least one of them, but note that you
need to be using a x10 ( low capacitance ) probe on your scope to have any
hope of seeing a signal ( mostly ). On some clock generators, notably one
that runs a DSP chip in a Sony HC system, as soon as you come near the
xtal
with even a low capacitance probe, the oscillator stops, never to restart
until you depower then repower to produce a reset to the DSP chip, so the
upshot of all this is that your DSP oscillator may possibly be running,
and
nothing to do with the fault, and stops when you try to scope it. A better
indication may be if there is any activity on any of the other pins.
However
this also does not give any certain proof of clock activity, as you may be
seeing shared-bus activity, originating elsewhere.

You may yet have xtal trouble though, particularly if it is a surface
mount
genuine crystal, rather than a ceramic resonator, which tend to be more
robust and reliable. I have had a number of these xtals fail in a variety
of
products. Sometimes, they are just reluctant to start up, and just
removing
the xtal, and soldering it back in the other way about, is enough to get
them going. If the problem genuinely is clock related, then it is far more
likely to be the xtal, than the chip.
If it has been subject to storm activity though, then the chip becomes
more
likely, as suggested by the other poster.

Arfa




I do use a x10 low capacity probe. I have tried to touch up the soldering
around the xtal (it's a ceramic resonator type if I'm not mistaken) but it
made no difference. I'm going to try the uP replacement and I'll report
back, successful or not.

Thanks for your reply.

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

"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

"ampdoc" wrote in message
...

"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



Hi Jammy,

I was tipped off to the resoldering fix to the EEPROM on a previous repair
of a Pioneer receiver and that's why that was the first thing I attempted.
So the question remains that if the EEPROM is defective, would that disable
the clock to the uP? Now I'm wondering about David Kuhajda's reply saying he
replaced his DSP IC whether he was talking about the uP or the EEPROM.

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

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.

"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

"David Farber" wrote in message
news:7eYvg.11020$Oj.1585@trnddc05...

"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



I telephoned Pioneer tech assistance for their suggestion. I was told that
95% of the time replacing IC9374 will correct the problem. I replaced it and
it didn't fix the problem. So then I replaced the uP and that did fix it. As
usual, David Kuhajda was right on target with his advice.

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