Hi everybody, i'm struggling with a taken-out-of-trash technics SL-P1, till now i've fixed every technics cd player that i touched but this is simply driving me nuts.
Everything is clean, broken solders were repaired, belts were changed, everything is re lubed.
when cd was insterted the focus coil went crazy and stopped, after a complete recalibration (without oscilloscope) i got focus and tracking lock, CLV is acheived (checked by manually moving the pickup) but no TOC, it wont even looks for it, seems like the RF signal is not beign processed, if i put a multimeter on DC on the RF testpoint i got 2.15v when working and 2v when stopped, which seems to be a normal value for RF...
Any help is appreciated. thanks!
Everything is clean, broken solders were repaired, belts were changed, everything is re lubed.
when cd was insterted the focus coil went crazy and stopped, after a complete recalibration (without oscilloscope) i got focus and tracking lock, CLV is acheived (checked by manually moving the pickup) but no TOC, it wont even looks for it, seems like the RF signal is not beign processed, if i put a multimeter on DC on the RF testpoint i got 2.15v when working and 2v when stopped, which seems to be a normal value for RF...
Any help is appreciated. thanks!
I have just fixed up an SL-P2 yesterday......
The player read the TOC sometimes but took for ages and couldn't make it to play at all. sometimes the disk spinned up like crazy......
Check if the lezerhead can move freely, plastic lock srew is open.
For the reading problem I had to adjust the focus offset to around 0-10mV.
TJ101 on the lezer pcb with VR103
and the tracking offset close to 0mV. TJ103 with VR106.
after those setup it played every track nicely .
I assume the p1 is very similar to p2. better check the SM before.
good luck
The player read the TOC sometimes but took for ages and couldn't make it to play at all. sometimes the disk spinned up like crazy......
Check if the lezerhead can move freely, plastic lock srew is open.
For the reading problem I had to adjust the focus offset to around 0-10mV.
TJ101 on the lezer pcb with VR103
and the tracking offset close to 0mV. TJ103 with VR106.
after those setup it played every track nicely .
I assume the p1 is very similar to p2. better check the SM before.
good luck
Well that seemed to help but i'm still kind of stuck or even worse, last night i got it following the spiral track , now somehow it looked for the TOC but got stuck, on other tryes on the same calibration the head went crazy to the outer part of the disk ending outside the disc, after lots of fiddling with the pots (it was a junk unit, every pot has been touched) it seems to be a lil better but still not reading, i'm started to think that i',m not getting it to work without an oscilloscope.
it did tranquilize me when it looked for TOC, i was affraid some electronic was fryed and the signal was not beign processed
I could not get my photo off the iphone to my linux pc, but if that helps almost all the potmeters where in the mid position except the tracking gain adj. VR104.
that was set almost all the way to the left. and focus gain VR101 was a bit off left from the middle.
I do have an old philips scope but it needs a good contact cleaning, getting very noisy,so I couldn't really use it.
Try again. I was messing with it 2-3 days when it started playing.
i will try to get those pics tomorrow
that was set almost all the way to the left. and focus gain VR101 was a bit off left from the middle.
I do have an old philips scope but it needs a good contact cleaning, getting very noisy,so I couldn't really use it.
Try again. I was messing with it 2-3 days when it started playing.
i will try to get those pics tomorrow
Thanks, i left it aside after repair the tray in switch that was broken and continued with other devices ande let my head cool off on that, but yes a picture of the potentiometers could be of help, thanks a lot!
Sorry for late replay, but I have worked on my scope.
That took me all day to take apart and clean all the switches and pushbuttons.
I just hopping it will work..... and I did not mess up anything.
here are the pictures, they shot before I setup the VR103 and VR106.
That took me all day to take apart and clean all the switches and pushbuttons.
I just hopping it will work..... and I did not mess up anything.
here are the pictures, they shot before I setup the VR103 and VR106.
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i know how that feels... yesterday i messed up a marantz 2265 receiver after putting loose a power transistor after a cleaning...
Anyway, thanks for the pictures, maybe later i will be testing, what concerns me about my cdp needing the OSC is that i have to dissasemble the pickup in order to clean its internals and surely is not exactly aligned as it was originally, the cleaning was a must since somehow there was a huge spill of a corrosive thing on the inside of the machine and everything was messed up
Anyway, thanks for the pictures, maybe later i will be testing, what concerns me about my cdp needing the OSC is that i have to dissasemble the pickup in order to clean its internals and surely is not exactly aligned as it was originally, the cleaning was a must since somehow there was a huge spill of a corrosive thing on the inside of the machine and everything was messed up
Okay, i've setted the pots as your picture then calibrated vr103 and 106, it did improve a lot but still doesn't reads
There's another pot on the mainboard that adjust disc speed, is already messed up too, and if that pot does not match with clock speed data is gonna be all scrambled, i guess i now need an OSC, but thanks for the original settings, now the machine is quieter and is one step closer to be working!
Will try to get the OSC and post result, thanks!
There's another pot on the mainboard that adjust disc speed, is already messed up too, and if that pot does not match with clock speed data is gonna be all scrambled, i guess i now need an OSC, but thanks for the original settings, now the machine is quieter and is one step closer to be working!
Will try to get the OSC and post result, thanks!
Your welcome!
Yes I know that pots (L301) I think that is for a PLL signal.
Yes you need a scope for that. get some old philips theye are very good,mine is still original except the power supply in which I had to change some capacitors. and clean all the knobs, switches for the best working.
Yes I know that pots (L301) I think that is for a PLL signal.
Yes you need a scope for that. get some old philips theye are very good,mine is still original except the power supply in which I had to change some capacitors. and clean all the knobs, switches for the best working.
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Just a small W124 200 ... I wish to have an 500 too. or some older model SL190.
Everything is still factory original except the sparkplugs and ignation cabels and the breakpads and rotors were changed at 150K/km.
I couldn't wish a better car, I love mine.
Everything is still factory original except the sparkplugs and ignation cabels and the breakpads and rotors were changed at 150K/km.
I couldn't wish a better car, I love mine.
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Okay.. i've been out of here since a while, got an oscilloscope finally, can't get the P1 to work...started following the calibration procedure from the manual but something is really wrong with this cd player.
had to adjust PLL since it was running across the screen, got the same picture as on the manual, then i proceed to calibrate CLV speed and the signal is not steady at all, asumming the disc speed is oscilating, also if i check the RF signal looks like is summed up with a sine signal, heavily distorting it...
any clue on it?
Thanks!
had to adjust PLL since it was running across the screen, got the same picture as on the manual, then i proceed to calibrate CLV speed and the signal is not steady at all, asumming the disc speed is oscilating, also if i check the RF signal looks like is summed up with a sine signal, heavily distorting it...
any clue on it?
Thanks!
Well in case anybody wants to know... one chip of the LSI module is fryed, that is causing all the trouble, when connected the 9v psu signal pulses, no matter what, RF signal is full of ripple (4.3mhz) and this IC gets hot... if i remove the supply, RF signal cleans up, psu stabilizes... so well... rest in peace.
I have been given a Technics SL-P1 which does not work properly.
What happens is that as soon as I turn the power on, the laser is activated but the lens is moved all toward the disc spindle. The disc motor keeps wobbling back and forth and when I press the open/close button, the disc motor starts rotating at full speed. The display always shows 0000. I get the same behaviour with and without a disc.
If I manually open the disc tray, it detects it is open and close it correctly.
If I manually move the pick-up, it detects it is not in the centre and move it back to the inner position.
I checked with the service manual and voltages on the servo board are more consistent with a Play position rather than Stop, but it basically never goes into stop mode.
Any idea what could be wrong ?
thanks
What happens is that as soon as I turn the power on, the laser is activated but the lens is moved all toward the disc spindle. The disc motor keeps wobbling back and forth and when I press the open/close button, the disc motor starts rotating at full speed. The display always shows 0000. I get the same behaviour with and without a disc.
If I manually open the disc tray, it detects it is open and close it correctly.
If I manually move the pick-up, it detects it is not in the centre and move it back to the inner position.
I checked with the service manual and voltages on the servo board are more consistent with a Play position rather than Stop, but it basically never goes into stop mode.
Any idea what could be wrong ?
thanks
Hi Enryfox, the failure you have looks a lot like a busted PSU, those older technics suffered a lot from dead capacitors, specially since you say your voltages vary depending of the consumption, PSU should be stable, try recapping and recheck all voltage regulators... also, servo capacitors must be replaced and a full recalibration might be needed, for this you will need an oscilloscope. Be careful to not mess with the mechanical alignment screws on the optical pickup, this will misalign it beyond repair
I actually checked the voltages from the PSU and they all looks fine; the servo board is powered by two lines at +/- 9.5 which are then regulated at +/- 5V and all those voltages are fine. No capacitors seems damaged, no leakage whatsoever.
What is not as expected is some levels on the IC's pins managing focus and tracking. I suspect a fault in the servo board because I was expecting the lens to move up and down for a few time but instead it does it only once and than the lens is moved laterally all toward one side.
If I unplug the connector from the servo board to the main board (the longer connector, the one with the signals from the servo) the CD player behaves normally: spindle motor spins twice and than it stops, disc tray opens and closes when pressing the button. But if I re-plug the servo connector it gets crazy again with the spindle rotating in both directions and accelerating at full speed when pressing open button.
What is not as expected is some levels on the IC's pins managing focus and tracking. I suspect a fault in the servo board because I was expecting the lens to move up and down for a few time but instead it does it only once and than the lens is moved laterally all toward one side.
If I unplug the connector from the servo board to the main board (the longer connector, the one with the signals from the servo) the CD player behaves normally: spindle motor spins twice and than it stops, disc tray opens and closes when pressing the button. But if I re-plug the servo connector it gets crazy again with the spindle rotating in both directions and accelerating at full speed when pressing open button.
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