This is related to:
Optical readers and writers (DVD and CD) that have problems with reading one or more of the supported media (DVD or CD).
My interest is in Pioneer DVR-109,110 and 111.
Problems: Not reading or writing cds, but reading and writing dvds.
Try first: Clean the lens - if it helps, you're done!
Possible solution: adjusting the laser beam intensity (increasing) and/or adjusting the tangential position of lens and/or complete optical mechanism.
All the information is highly unoficial and gathered from my friends and the internet (allmighty)
This troubleshoot is not complete and is given in as-is form, I hope that together we can answer all remaining questions, and live and burn happily ever after
Opened 110 looks like this:
And like this:
Ok, the light-blue are ruff position adjusting, for the moment, i would not tamper with them (jet).
Yellow is the lens tangential position screw.
Red are the pot's (potentiometers). One of them is for DVD and other for CD beam intensity adjusting.
That's about it You can tamper with these screws for hours and maybe there would be a succes - but there is no way to know.
For furter progress i need help.
The holy gral of my quest is the service manual of Pioneer 109,110 and especially 111. With osciloscope you can measure the 'quality' of signal and so detect if you're on the right way to the optimal position and laser intensity, but where to pick up and what kind of signal should there be?