VOGONS


First post, by aha2940

User metadata
Rank Member
Rank
Member

Hi guys, just as the title says, one of my PC DVD drives will not open fully after pressing the open/close button. The drive is a Sony DW-Q28A. It works fine other than the tray not opening completely. It opens about 90%, but then the drive closes it again after a couple seconds. If I pull it manually the missing 10%, then it stays open, and it will close completely when pushing the open/close button. I think I know what you are thinking: "the rubber belt is damaged, get a replacement". There's the issue: this drive does not have any rubber belt, it's all gears inside, so the usual fixes do not apply. I already disassembled the drive, cleaned the gears, added a bit of white silicone grease to the rails, but nothing helps. I also replaced the open/close motor with another exact one taken from a different drive, same problem. Any ideas? maybe these electric motors lose torque/power over time? adding the motor a drop of sewing machine oil may help? or will it damage it? Thanks for any help.

Reply 1 of 11, by yawetaG

User metadata
Rank Oldbie
Rank
Oldbie

There should be a sensor or switch somewhere in the drive mechanism that the drive uses to sense when the drive is closed or fully open. Perhaps that switch is damaged (if mechanical) or dirty.

Likewise, dust in the open/close button can cause erratic behaviour.

Reply 2 of 11, by Cyberdyne

User metadata
Rank Member
Rank
Member

I have had problems with many CD and DVD trays not opening/closing, problem is wear of plastic parts and aging of lubrication, never sensors.

I am aroused about any X86 motherboard that has full functional ISA slot. I think i have problem. Not really into that original (Turbo) XT,286,386 and CGA/EGA stuff. So just a DOS nut.

Reply 3 of 11, by cyclone3d

User metadata
Rank l33t
Rank
l33t

I had one that was doing something similar. Ended up being that some plastic bit had broken off inside the drive. I ended up trashing the drive because it broke even more when I was trying to figure out where the broken piece came from.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header
Epstein didn't kill himself

Reply 4 of 11, by Cyberdyne

User metadata
Rank Member
Rank
Member

Cheap plastic plus grease just breaks those drives in some time. Especially if they have worked in a dusty enviroment in the past.

I am aroused about any X86 motherboard that has full functional ISA slot. I think i have problem. Not really into that original (Turbo) XT,286,386 and CGA/EGA stuff. So just a DOS nut.

Reply 5 of 11, by aha2940

User metadata
Rank Member
Rank
Member
yawetaG wrote on 2020-09-15, 04:59:

There should be a sensor or switch somewhere in the drive mechanism that the drive uses to sense when the drive is closed or fully open. Perhaps that switch is damaged (if mechanical) or dirty.

Likewise, dust in the open/close button can cause erratic behaviour.

Hi, the sensor is there and it works correctly both ways, however the problem is that the tray opens until a bit before pressing the switch, so the drive never sees the tray as open and that's why it's closed again.

Cyberdyne wrote on 2020-09-15, 05:02:

I have had problems with many CD and DVD trays not opening/closing, problem is wear of plastic parts and aging of lubrication, never sensors.

I took a careful look at the plastic gears and rails on the drive and can't find any wear on them, they seem to be perfect: no missing/broken teeth on any gears or anything. I noticed the drive had no lubrication anywhere, which seemed odd so I added a bit of grease on the rails and gears but nothing changed.

cyclone3d wrote on 2020-09-15, 06:10:

I had one that was doing something similar. Ended up being that some plastic bit had broken off inside the drive. I ended up trashing the drive because it broke even more when I was trying to figure out where the broken piece came from.

Cyberdyne wrote on 2020-09-15, 06:29:

Cheap plastic plus grease just breaks those drives in some time. Especially if they have worked in a dusty enviroment in the past.

Well, I'm no plastics specialist, but quality here does not seem that cheap. It does not look that different from an ABS Lego piece, and those are high quality in my experience. Also, i can't find any broken pieces and I cleaned them already. Very strange this. I was thinking that maybe the motor had lost power due to aging, is that possible?

Reply 6 of 11, by quicknick

User metadata
Rank Member
Rank
Member

Or the circuit driving the motor isn't providing the required juice anymore.
You can test this by disconnecting it completely from the board and applying 5 volts from a suitable supply.

Or to rule out mechanical problems, manually extend the tray all the way. Does it go nicely until the end, or is there noticeable increased friction from the point where it tends to stop (before reaching the "tray open" sensor)?

Reply 7 of 11, by aha2940

User metadata
Rank Member
Rank
Member
quicknick wrote on 2020-09-15, 17:21:

Or the circuit driving the motor isn't providing the required juice anymore.
You can test this by disconnecting it completely from the board and applying 5 volts from a suitable supply.

Or to rule out mechanical problems, manually extend the tray all the way. Does it go nicely until the end, or is there noticeable increased friction from the point where it tends to stop (before reaching the "tray open" sensor)?

Thanks for the suggestion. I did the test, and applying 5V from the power supply directly to the motor (disconnected from the DVD drive board, of course) the drive opens and closes perfectly. It even does so very fast and with much force, so I think the problem does lie on the voltage (or power?) the motor is receiving from the DVD drive. Any ideas what I could look for now? the drive only has a few electrolytic capacitors, nothing else that I can see as "replaceable" but I do not even know if those capacitors have anything to do with the tray motor or not.

Reply 9 of 11, by pentiumspeed

User metadata
Rank Oldbie
Rank
Oldbie

Aged, leaky shorting motors will put more strain on the motor IC driver which is sending out fixed voltage for smooth, controlled motion, and power droops slightly causing the drawer to not open properly. Like you said drawer opens violently using 5V juice, is what exactly that motor IC is for.

Back in the day, our techs and when I used to fix TVs when CRT glass bulb and spinning CD and DVD players is the king. Well, we would find the shorts in the commutator gaps would stop the cd player from spinning the disc then meant wouldn't play music or spin uncontrollably. Either clean out the conductive dirt in the commutator gaps (mechanical cleaning is only way, meant disassembly of the said motor), or replace with NEW motor or correct one, not used.

Even capacitors on that little board can be cantankerous.

I had seen a amp shut down intermittently with a leaky two wire cooling fan that used commutator motor (intermittent cooling on demand during loud music passages), a smart tech told the audio repair guy to replace that fan which fixed that. I had a large rear projection TV that used pair of ultra quiet (80mm computer type made by NONOISE brand) fans get little stickum when stopped, still look good, but not quite right, I did clean out the dust but still, and TV would shut down right after turning on. The fans were 2 wire only and TV has two current measuring circuits built into motherboard for the two fans. Flicked both fans into motion at same time and turn it on kept TV alive even fans are running on their own. Replaced both fans with new fixed that.

Cheers,

Great Northern aka Canada.

Reply 11 of 11, by pentiumspeed

User metadata
Rank Oldbie
Rank
Oldbie

lubrication dried out and gears turning or sliding will cause this too. I'm talking about the gears that turns on the plastic round things, lube these with lithium grease made for plastic.

Cheers,

Great Northern aka Canada.