Hi,
My Shanling T80 has been giving me "No Disc" error over the last year. I had to wait until it wormed up and then it used to work. It finally stopped recognizing CDs no matter what I did.
I followed the link thread below and ordered and replaced the Philips laser unit VAM-1201/1202 and to my disappointment it did not fix the problem.
When I open and close the CD drawer the CD does not spin, so I then took a 1.5V battery and tested the motor and on both the original and the new laser units the motor did spin!
I rechecked all the ribbon cables and no luck! I then proceeded and measured some voltages. The +3.3V and +5V are getting to the PCB, the one connected (under) to the transport. I then measured the voltages on the MO+ and MO-, these are the yellow and green wires going to the CD motor. When I cycle the player on/off, to activate the motor spinning mechanism, the MO- is measuring +2.49V on CD reading and then drops to +2.31V and stays there with "No Disc" on display . The MO+ is measuring +2.47V on turn-on and then drops to +2.28V and I get the "No Disc" on display.
To me this does not look right, there should be some MO- to MO+ voltage but there is none? These measurements I took both on the PCB and at the motor.
I am at lost here, any help would be greatly appreciated...
http://www.diyaudio.com/forums/digital-source/98184-shanling-nightmare-5.html
My Shanling T80 has been giving me "No Disc" error over the last year. I had to wait until it wormed up and then it used to work. It finally stopped recognizing CDs no matter what I did.
I followed the link thread below and ordered and replaced the Philips laser unit VAM-1201/1202 and to my disappointment it did not fix the problem.
When I open and close the CD drawer the CD does not spin, so I then took a 1.5V battery and tested the motor and on both the original and the new laser units the motor did spin!
I rechecked all the ribbon cables and no luck! I then proceeded and measured some voltages. The +3.3V and +5V are getting to the PCB, the one connected (under) to the transport. I then measured the voltages on the MO+ and MO-, these are the yellow and green wires going to the CD motor. When I cycle the player on/off, to activate the motor spinning mechanism, the MO- is measuring +2.49V on CD reading and then drops to +2.31V and stays there with "No Disc" on display . The MO+ is measuring +2.47V on turn-on and then drops to +2.28V and I get the "No Disc" on display.
To me this does not look right, there should be some MO- to MO+ voltage but there is none? These measurements I took both on the PCB and at the motor.
I am at lost here, any help would be greatly appreciated...
http://www.diyaudio.com/forums/digital-source/98184-shanling-nightmare-5.html
Some more information. There is a dual driver IC TDA7073 that is suppose to drive the CD motor, pin 7 is the Vref and is measuring 0v. Pin 1 is also the Vref for the second stage driver and there is +1.6V on there and there is an output on pins 13 and 16! So It looks like at least one stage on the 7073 is working. I wish I had the schematic for this board...
Tried to contact Shanling but no luck getting to buy the transport or transport control board. They did offer to send it to them for repair, China I think, for $200 for shipping...
Could anyone help with getting a schematic for the transport control board so I can troubleshoot it? It would be a shame to scrap this player, really good sound after some simple modifications...
Could anyone help with getting a schematic for the transport control board so I can troubleshoot it? It would be a shame to scrap this player, really good sound after some simple modifications...
I did some troubleshooting (check my other post for details) and it looks like the control board located under the transport is not supplying voltage to laser. The problem is although I have masters in electrical engineering I am only going by what I can trace on the board. It's a multilayer board and I cannot see all the traces, I need the schematic to troubleshoot and locate the faulty device.
Sent from my SGH-M919 using Tapatalk
Sent from my SGH-M919 using Tapatalk
One approach would be to look at some Philips manuals that use the same pickup and trace the laser "on/off" line.
Are you certain its not lit. Have you looked at the lens from above via a digital camera that is responsive to near infra red.
Infrared remote test - YouTube
Are you certain its not lit. Have you looked at the lens from above via a digital camera that is responsive to near infra red.
Infrared remote test - YouTube
I'm experiencing the same thing on my Shanling T-80 - the no disc error!?
It was playing fine, then suddenly, I removed one disc, inserted another and... nothing?!
I took off the cover and can see the laser lighting up when the tray retracts, but that's it.
Any ideas of how to track down the source of the problem?
cheers,
Norm
It was playing fine, then suddenly, I removed one disc, inserted another and... nothing?!
I took off the cover and can see the laser lighting up when the tray retracts, but that's it.
Any ideas of how to track down the source of the problem?
cheers,
Norm
Judging by the threads it seems a common issue.
If the laser is lit and performs a focus search then check that the sled is in the start position by moving it manually and then opening and closing the drawer. It should always return correctly to the start position. The disc motor won't spin until focus is found... so you need to check the FOK (focus OK line) to the system control and take it from there. Identify the chip set used (probably Philips) and then try and find a similar Philips player to help with circuit identification. Try and check all the rails too by identifying the chips and looking at the data sheets to get an idea of correct values.
If the laser is lit and performs a focus search then check that the sled is in the start position by moving it manually and then opening and closing the drawer. It should always return correctly to the start position. The disc motor won't spin until focus is found... so you need to check the FOK (focus OK line) to the system control and take it from there. Identify the chip set used (probably Philips) and then try and find a similar Philips player to help with circuit identification. Try and check all the rails too by identifying the chips and looking at the data sheets to get an idea of correct values.
If the player is still assembled then open the drawer and pull the mains plug out. You will see/feel a bendy plastic tab that stops the tray popping out. Just bend it away and gently remove the tray.
If you have the mech out of the player and disconnected then apply a 1.5 volt AA cell across the tray motor to get it started. Then you can grip the tray and pull.
If you have the mech out of the player and disconnected then apply a 1.5 volt AA cell across the tray motor to get it started. Then you can grip the tray and pull.
OK, so I figured out how to remove the tray, installed the VAM unit, re-installed everything and.... same error?
Curiously, the old (defective) unit was a VAM 1202, not a Philips? It had obviously been replaced already.
What's the failure rate of these VAM units? Could it really be a defective unit, or might it be something else?
Curiously, the old (defective) unit was a VAM 1202, not a Philips? It had obviously been replaced already.
What's the failure rate of these VAM units? Could it really be a defective unit, or might it be something else?
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