info@toniolo
New Member
Hello,
I'm a repair tech based in Malta (Europe), a client brought in a SONY SCD-1 not reading CDs
The unit fails to read the table of contents. After consultation of service manual, the Adjustment mode was used to determine the cause of this failure. Code 30 (Disk check) determines the type of disc correctly. Any other attempts in the adjustment menu, such as focus search, play, sled motor, fail.
The unit came with a second laser unit which the owner says has been bought and replacement attempted by another technician. The attempt failed. According to the owner, the unit was brought in with the original laser unit.
Attempted laser unit change, the problem persists.
Capacitors on RF Board, have been sample tested, found within reasonable tolerance.
Suspected FFC cables connecting the RF Board to the mainboard. THese had quite some kinks. After testing, they look ok and have been majorly ruled out.
The symptoms the unit exhibits do not seem to suggest a faulty laser unit. It is unknown if the disk check performed is reading optically from disc or as opposed to utilizing another form of detection.
On to the RF Board, the RF output was probed with an oscilloscope and the resulting waveform does not seem to be what you would find on the output of the RF amplifier. This suggests either a faulty amplifier or the lack of input to the amplifier.
The following measurement was taken as follows:
All components marked red have been checked.
B+ Measured 4.95V
Yellow channel - Input at TP01 (the input of the amplifier)
Blue Channel - Output DSDRF+
This resulting waveform is an almost nil input (yellow), with a noisy and glitchy output (Blue) at a strange frequency of 123kHz, not what you’d expect on the output of the RF amplifier.
Is it worth checking PD01/02?
Also suspected is the servo motor amplifier which is found on the RF Board. The sled servo moves at some point while attempting to read the CD. However, in adjustment mode, when the sled motor is turned on (Code 07) it does not move. Could this be preventing the input to the amplifier?
What would the next steps be in troubleshooting to determine the cause of the problem?
Does anyone know where I can source parts (even cannibalized) for this unit ?
Thanks,
T
I'm a repair tech based in Malta (Europe), a client brought in a SONY SCD-1 not reading CDs
The unit fails to read the table of contents. After consultation of service manual, the Adjustment mode was used to determine the cause of this failure. Code 30 (Disk check) determines the type of disc correctly. Any other attempts in the adjustment menu, such as focus search, play, sled motor, fail.
The unit came with a second laser unit which the owner says has been bought and replacement attempted by another technician. The attempt failed. According to the owner, the unit was brought in with the original laser unit.
Attempted laser unit change, the problem persists.
Capacitors on RF Board, have been sample tested, found within reasonable tolerance.
Suspected FFC cables connecting the RF Board to the mainboard. THese had quite some kinks. After testing, they look ok and have been majorly ruled out.
The symptoms the unit exhibits do not seem to suggest a faulty laser unit. It is unknown if the disk check performed is reading optically from disc or as opposed to utilizing another form of detection.
On to the RF Board, the RF output was probed with an oscilloscope and the resulting waveform does not seem to be what you would find on the output of the RF amplifier. This suggests either a faulty amplifier or the lack of input to the amplifier.
The following measurement was taken as follows:
All components marked red have been checked.
B+ Measured 4.95V
Yellow channel - Input at TP01 (the input of the amplifier)
Blue Channel - Output DSDRF+
This resulting waveform is an almost nil input (yellow), with a noisy and glitchy output (Blue) at a strange frequency of 123kHz, not what you’d expect on the output of the RF amplifier.
Is it worth checking PD01/02?
Also suspected is the servo motor amplifier which is found on the RF Board. The sled servo moves at some point while attempting to read the CD. However, in adjustment mode, when the sled motor is turned on (Code 07) it does not move. Could this be preventing the input to the amplifier?
What would the next steps be in troubleshooting to determine the cause of the problem?
Does anyone know where I can source parts (even cannibalized) for this unit ?
Thanks,
T