1. Make sure the disc is a working one.
2. Clean the lens using a q-tip with alcohol. (You've already done.)
3. Adjust the power of the reading head by rotating the knob clockwise a little bit. The knob is near the lens, either under or at the side of it. You could use a multimeter to check its resistance while adjusting it. Turning it clockwise will reduce the resistance. Don't turning it too much one time then check to see if it reads the disc normally, if not, repeat the procedure.
4. If none of the above method works, it might be the laser head is dead or the circuit controlling it failed.

GunKneeNeon wrote on 2023-06-01, 10:15:

1. Make sure the disc is a working one. 2. Clean the lens using a q-tip with alcohol. (You've already done.) 3. Adjust the power […]
Show full quote

1. Make sure the disc is a working one.
2. Clean the lens using a q-tip with alcohol. (You've already done.)
3. Adjust the power of the reading head by rotating the knob clockwise a little bit. The knob is near the lens, either under or at the side of it. You could use a multimeter to check its resistance while adjusting it. Turning it clockwise will reduce the resistance. Don't turning it too much one time then check to see if it reads the disc normally, if not, repeat the procedure.
4. If none of the above method works, it might be the laser head is dead or the circuit controlling it failed.

Thanks for your reply, but i got bad news. I adjusted the knob in a lot of positions but i only managed to get things slightly better.

The DVD are being read a bit better, ( CD Speed 99 still can't complete the benchmark because at some points appears an error )

CD are still problematic like and the laser head goes crazy everytime and gets noisy.

I also used some strong compressed air all over, inside the drive but nothing.

@_StIwY_
Note that a disc drive like yours, plays both CD and DVD, has two different heads for CD and DVD respectively, hence the fact that it read DVDs better. There are two knobs there. What you have done, I assume, was to tune the knob for DVD head. So you've noticed the DVDs are read better. You have to locate the knob for CD and tune that. See the picture below, it's my DVD-ROM.

GunKneeNeon wrote on 2023-06-01, 15:58:

@_StIwY_
Note that a disc drive like yours, plays both CD and DVD, has two different heads for CD and DVD respectively, hence the fact that it read DVDs better. There are two knobs there. What you have done, I assume, was to tune the knob for DVD head. So you've noticed the DVDs are read better. You have to locate the knob for CD and tune that. See the picture below, it's my DVD-ROM.

knobs.png

So, looks like i was adjusting the wrong knob. The knobs for DVD - CD are these

......but i was adjusting only this knob, at this point i don't know what's this knob is for ?

_StIwY_ wrote on 2023-06-02, 09:23:

......but i was adjusting only this knob, at this point i don't know what's this knob is for ?

This is simply a screw.

GunKneeNeon wrote on 2023-06-02, 15:42:

_StIwY_ wrote on 2023-06-02, 09:23:

......but i was adjusting only this knob, at this point i don't know what's this knob is for ?

This is simply a screw.

Oh......all right xD.

So....after multiple tests there was no margin for improvements. It's been two hours, i rotated the knob a little clockwise....counterclockwise......a bit less.....a bit more.....nothing!! CD Speed 99 keeps failing at at all test.......the noisy laser head keep smashing forward and backwards in the rails as shown in the video

I assume there is no hope, right ?

.....but......check this out

i'm testing another Pioneer ( the DVD-105SZ ) which is basically the same model. It read CD-R flawlessy, but struggle....with DVDs and CD-RWs.

CD Speed 99 fails on "random seek" test. My patience is running out....

_StIwY_ wrote on 2023-06-02, 16:02:

So....after multiple tests there was no margin for improvements. It's been two hours, i rotated the knob a little clockwise....counterclockwise......a bit less.....a bit more.....nothing!! CD Speed 99 keeps failing at at all test.......the noisy laser head keep smashing forward and backwards in the rails as shown in the video

I assume there is no hope, right ?

What your laser head was doing is tracking, it couldn't locate the track successfully. As an end user what we can do is pretty limited. In a standalone CD/DVD player, there are more pots you can adjust, the focus gain/tracking gain/ef balance, most of which doesn't exist in a disc drive for computer use like yours. As for tuning the pots, it gets a little tricky sometimes, as a small amount of adjustment makes a huge difference. See this video for reference. This guy does it very well.

_StIwY_ wrote on 2023-06-02, 16:02:

i'm testing another Pioneer ( the DVD-105SZ ) which is basically the same model. It read CD-R flawlessy, but struggle....with DVDs and CD-RWs.

CD Speed 99 fails on "random seek" test. My patience is running out....

DO test the drive with commercial discs, as those recordable discs are difficult to read for older drives. Especially for CD-RWs, they are way more difficult to read even than CD-Rs. And you have to keep in mind, don't over do it, or you'll end up..... See the picture.

GunKneeNeon wrote on 2023-06-02, 19:42:

What your laser head was doing is tracking, it couldn't locate the track successfully.

Yes but it bashes violently compared to the other one. So maybe it have problems on the alignment, or motors, or who knows where is the problem! At this point could be anything.

Anyway i tried almost any knobs configurations, and this one looks to have no hopes. The other one reads normal CD and CD-R, but does not read DVD anymore, maybe i turned the knob too much at some point and the laser got ruined. No matter what, if i put inside a DVD it ejects the disc in three seconds.

I guess it's time to throw them away 🙁

Replace any electrolytic capacitors in the drive first. That usually brings back drives that won't read disks reliably. The laser diode should not even need adjustment if you do that.

wiretap wrote on 2023-06-03, 10:58:

Replace any electrolytic capacitors in the drive first. That usually brings back drives that won't read disks reliably. The laser diode should not even need adjustment if you do that.

I give up. I don't have tools / skill to do such a thing. I could send these drives to someone if you want to. Contact me with a private message.

try resetting the knobs/adjustment's back to previous settings , and cleaning entire inside with electronic contact cleaner. Learned the hard way that the rubber pulley ages badly and has problems eventually inside drives that use it mainly.

Or if you say only DVD problems , it may need a firmware upgrade/downgrade/reflash.... test also on virtualized os with specific drive drivers.(may be relevant).

I have a similar problem, but it occurs more sporadically, in general the drive slows down but is fully usable. In case the drive stops working, I have an idea. Maybe it is possible to transfer the head from a no-slot-in drive from the same period? For example, Pioneer DVD-114. These drives can be bought for pennies, swapping the head is very simple, and you can bring a nice slot-in back to life