Hi,
upon resurrecting a Pioneer PD 73, I've carefully completed the calibration process as described in the Service Manual (see previous post).
I've in order:
This setup works perfectly with pristine CDs and CD-Rs but when the CD has scratches, black spots or anything far from a perfect surface, I get issues.
Let me explain:
I've tried to play with Tracking Gain and Focus Gain, but I had no good luck...(yet)
Any suggestion? Could it be that the capacitor around the RF Amp / Servo micro are dried and must be replaced?
Many thanks for any valuable suggestion.
PS... the little PD-7300 (which mounts the same identical optical unit PWY-1011) reads flawlessly even the worst disc.
upon resurrecting a Pioneer PD 73, I've carefully completed the calibration process as described in the Service Manual (see previous post).
I've in order:
- set Tracking Offset to ~0V
- set Focus Offset to ~0V
- set RF Offset to ~100mV
- set the RF level to ~1.5V
- set the grating for largest T-Err signal after Null Point
- adjusted tracking balance after grating
- adjusted tangential and radial screws for optimal eye-pattern
This setup works perfectly with pristine CDs and CD-Rs but when the CD has scratches, black spots or anything far from a perfect surface, I get issues.
Let me explain:
- in Test mode, everything is read no skips, no jumps just music despite the surfaces defects
- in "normal" mode, on certain troubled tracks (those that are affected by defects) the player struggles to find the track start or skips seconds while reading the track.
I've tried to play with Tracking Gain and Focus Gain, but I had no good luck...(yet)
Any suggestion? Could it be that the capacitor around the RF Amp / Servo micro are dried and must be replaced?
Many thanks for any valuable suggestion.
PS... the little PD-7300 (which mounts the same identical optical unit PWY-1011) reads flawlessly even the worst disc.
I would check the main power supply, and see if there any known issues by checking on line.
And sometimes dirty power can damage components beyond repair.
I would also see if the lens has gone weak.
And sometimes dirty power can damage components beyond repair.
I would also see if the lens has gone weak.
Hi, I made some progresses and now I can reliably read most of the tracks with defects however not with the same stability I get with the PD 7300.
Below the images respectively of RF, FocusErr, Tracking Err.
RF detail showing (red boxes) signal artifacts
RF value ~1.6Vpp (channel 1, 1V/div)
Tracking Error (channel 2, 500mV/div)
Focus Error (channel 2, 200mV/div)
Below the images respectively of RF, FocusErr, Tracking Err.
RF detail showing (red boxes) signal artifacts
RF value ~1.6Vpp (channel 1, 1V/div)
Tracking Error (channel 2, 500mV/div)
Focus Error (channel 2, 200mV/div)
The Central control on both channels of your Vertical Amps on your 'scope aren't set to the ''Cal'' position so you will be getting erroneous readings.
To me it looks like too much RF signal, that distortion at the top and bottom of the trace looks to me like the circuit is being over-loaded.
Channel 1 ? set to 1V/div so is reading over 2 V pk-pk and you have the cental control 'turned down' so am guessing it's even more that that.
To me it looks like too much RF signal, that distortion at the top and bottom of the trace looks to me like the circuit is being over-loaded.
Channel 1 ? set to 1V/div so is reading over 2 V pk-pk and you have the cental control 'turned down' so am guessing it's even more that that.
Thanks percival007 for your comments.
The Cal knob is out of the default position (all right) because the oscilloscope is old and isn't perfectly calibrated anymore. Usually I take signals I'm sure about and I set the calibration knob to make sure that I'm reading the right measure.
About your remark on the 2V p-p, consider the whole EYE pattern including the overstrikes, yes it's around 2V with standard CDs but when I use a different media like a CD-R then it drops down to 1.4V. However even reducing the RF level, and bringing it for standard CD to default value of 1.5Vp-p makes no difference in terms of tracking skip.
In the last days I've rechecked also radial and tangential calibration, but the improvements I can achieve are marginal...The more I'm trying to recalibrate it the more I feel like something has connected to old caps that maybe dried out.
Question to everybody, how good are WURTH capacitors compared to Nichicon, Rubicon or Panasonic? I've found many WURTH caps running with specs of 10000h / 105C
Thanks again for any valuable comment.
The Cal knob is out of the default position (all right) because the oscilloscope is old and isn't perfectly calibrated anymore. Usually I take signals I'm sure about and I set the calibration knob to make sure that I'm reading the right measure.
About your remark on the 2V p-p, consider the whole EYE pattern including the overstrikes, yes it's around 2V with standard CDs but when I use a different media like a CD-R then it drops down to 1.4V. However even reducing the RF level, and bringing it for standard CD to default value of 1.5Vp-p makes no difference in terms of tracking skip.
In the last days I've rechecked also radial and tangential calibration, but the improvements I can achieve are marginal...The more I'm trying to recalibrate it the more I feel like something has connected to old caps that maybe dried out.
Question to everybody, how good are WURTH capacitors compared to Nichicon, Rubicon or Panasonic? I've found many WURTH caps running with specs of 10000h / 105C
Thanks again for any valuable comment.