Just some notes, should someone find them useful... Or if I ever need
to debug them again.

First, a Pioneer PD-M450. It cost me 8 eur and was supposed to be in
working order. On some CD-R's it would have repetitive static and noise
at about the disc spin rate. Grabbing the flex cable to the pickup with
my fingers made it worse. The only thing that made it lessen was
turning the laser power up (because it made the signal stronger, I
guess). I actually left it "fixed" like this and used it for a while. I
wasn't happy with it though, so recently I opened it up again, turned
the laser pot back to where it was and started over. I noticed that the
problem only appeared with the cover on. The PD-M450 is a rather slim
unit, and you probably guessed that the printed flexible cable was
rubbing against the "ceiling". I taped a piece of foam on the cable to
keep it away from the metal casing, and the problem seems to have gone
away. I'm hoping that the 10-20 hours of use with higher laser power
didn't affect its lifespan too much.

The second unit was a PD-M701. Cost me 6 eur, broken. It had all kinds
of weird problems: would start to play then abort, would not recognize
discs, would ignore some commands but not others etc. Cleaning or
adjustments made no difference. The repairfaq mentioned a problem with
white printed flexible cables, and this player had one. Moving it
around while playing confirmed that the cable was to blame. The "fix"
involved folding the broken part of the cable into a bight and taping
it together... This apparently forces the broken strip ends together
and the tape keeps it from moving. I know it's just a temporary fix,
but it's my own player so what the hey. Pioneer Finland hasn't yet told
me what the cost for a new flex cable is. The player is very nice
otherwise, with a quality feel to it that the PD-M450 doesn't have.


Rambling on, Ilkka

You have stumbled across one of the common problems with the otherwise
very good Pioneer cartridge CD players.
Continue trying to contact Pioneer Finland and purchase the proper
replacement flex cables to complete the repair of your units.
electricitym
..
..
..

wrote in message
oups.com...
Just some notes, should someone find them useful... Or if I ever need
to debug them again.

First, a Pioneer PD-M450. It cost me 8 eur and was supposed to be in
working order. On some CD-R's it would have repetitive static and noise
at about the disc spin rate. Grabbing the flex cable to the pickup with
my fingers made it worse. The only thing that made it lessen was
turning the laser power up (because it made the signal stronger, I
guess). I actually left it "fixed" like this and used it for a while. I
wasn't happy with it though, so recently I opened it up again, turned
the laser pot back to where it was and started over. I noticed that the
problem only appeared with the cover on. The PD-M450 is a rather slim
unit, and you probably guessed that the printed flexible cable was
rubbing against the "ceiling". I taped a piece of foam on the cable to
keep it away from the metal casing, and the problem seems to have gone
away. I'm hoping that the 10-20 hours of use with higher laser power
didn't affect its lifespan too much.

The second unit was a PD-M701. Cost me 6 eur, broken. It had all kinds
of weird problems: would start to play then abort, would not recognize
discs, would ignore some commands but not others etc. Cleaning or
adjustments made no difference. The repairfaq mentioned a problem with
white printed flexible cables, and this player had one. Moving it
around while playing confirmed that the cable was to blame. The "fix"
involved folding the broken part of the cable into a bight and taping
it together... This apparently forces the broken strip ends together
and the tape keeps it from moving. I know it's just a temporary fix,
but it's my own player so what the hey. Pioneer Finland hasn't yet told
me what the cost for a new flex cable is. The player is very nice
otherwise, with a quality feel to it that the PD-M450 doesn't have.


Rambling on, Ilkka


To correctly set the laser power on Pioneer players, you should 'scope TP1
( "RF" ) and set the laser power pot on the orange ribbon cable for 1 to
1.2v p-p.

When servicing any of this series, you should also lock up the 'scope on the
RF eye pattern, and expand the sweep until you can see the ' diamonds '
clearly. They should be steady and stable, not jittering horizontally. If
they are, particularly with the disc towards the end and rotating slowly, it
indicates the beginnings of spindle motor trouble, which is very common.
Lasers are exceptionally reliable, and in my experience, much more tolerant
of over run from inexperienced engineers turning them up, than some others -
Sony for instance ( which shouldn't be adjusted in the first place ... )

Arfa

The replacement cable is part number PNP-1343 (improved part)

Mark Z.


wrote in message
oups.com...
Just some notes, should someone find them useful... Or if I ever need
to debug them again.

First, a Pioneer PD-M450. It cost me 8 eur and was supposed to be in
working order. On some CD-R's it would have repetitive static and noise
at about the disc spin rate. Grabbing the flex cable to the pickup with
my fingers made it worse. The only thing that made it lessen was
turning the laser power up (because it made the signal stronger, I
guess). I actually left it "fixed" like this and used it for a while. I
wasn't happy with it though, so recently I opened it up again, turned
the laser pot back to where it was and started over. I noticed that the
problem only appeared with the cover on. The PD-M450 is a rather slim
unit, and you probably guessed that the printed flexible cable was
rubbing against the "ceiling". I taped a piece of foam on the cable to
keep it away from the metal casing, and the problem seems to have gone
away. I'm hoping that the 10-20 hours of use with higher laser power
didn't affect its lifespan too much.

The second unit was a PD-M701. Cost me 6 eur, broken. It had all kinds
of weird problems: would start to play then abort, would not recognize
discs, would ignore some commands but not others etc. Cleaning or
adjustments made no difference. The repairfaq mentioned a problem with
white printed flexible cables, and this player had one. Moving it
around while playing confirmed that the cable was to blame. The "fix"
involved folding the broken part of the cable into a bight and taping
it together... This apparently forces the broken strip ends together
and the tape keeps it from moving. I know it's just a temporary fix,
but it's my own player so what the hey. Pioneer Finland hasn't yet told
me what the cost for a new flex cable is. The player is very nice
otherwise, with a quality feel to it that the PD-M450 doesn't have.


Rambling on, Ilkka

On the PDM-450,

might help to record the CD-R's at a lower speed, or try a different brand
of disc.

Mark Z .


wrote in message
oups.com...
Just some notes, should someone find them useful... Or if I ever need
to debug them again.

First, a Pioneer PD-M450. It cost me 8 eur and was supposed to be in
working order. On some CD-R's it would have repetitive static and noise
at about the disc spin rate. Grabbing the flex cable to the pickup with
my fingers made it worse. The only thing that made it lessen was
turning the laser power up (because it made the signal stronger, I
guess). I actually left it "fixed" like this and used it for a while. I
wasn't happy with it though, so recently I opened it up again, turned
the laser pot back to where it was and started over. I noticed that the
problem only appeared with the cover on. The PD-M450 is a rather slim
unit, and you probably guessed that the printed flexible cable was
rubbing against the "ceiling". I taped a piece of foam on the cable to
keep it away from the metal casing, and the problem seems to have gone
away. I'm hoping that the 10-20 hours of use with higher laser power
didn't affect its lifespan too much.

The second unit was a PD-M701. Cost me 6 eur, broken. It had all kinds
of weird problems: would start to play then abort, would not recognize
discs, would ignore some commands but not others etc. Cleaning or
adjustments made no difference. The repairfaq mentioned a problem with
white printed flexible cables, and this player had one. Moving it
around while playing confirmed that the cable was to blame. The "fix"
involved folding the broken part of the cable into a bight and taping
it together... This apparently forces the broken strip ends together
and the tape keeps it from moving. I know it's just a temporary fix,
but it's my own player so what the hey. Pioneer Finland hasn't yet told
me what the cost for a new flex cable is. The player is very nice
otherwise, with a quality feel to it that the PD-M450 doesn't have.


Rambling on, Ilkka