non working CD side of a Duo

[Soviet Conscript]

picked up a turbo duo recently which i knew was not running CD's. the unit plays HU cards perfectly.

upon opening up the unit i found the probable cause. lotsa dead roaches mostly crushed in the gears, pretty gross stuff. so after removeing the bugs disassembleing the laser assembly cleaning it and then lubricateing the gears and slide poles i put it back together and....nothing

so i'm at a loss at what to do now. i can say a few things

1) upon putting a cd in and hitting start it says "please wait a moment" but nothing happens at all. the cd does not spin or make any noise

2) the laser does not move if you try to move it manually. i opened a duo-r once and i seem to recall being able to slide the laser up and down the slide poles manually.

3) if you do move the laser on the poles which you can do if you disassemble the assembly and then turn the power on the laser does return to its starting position so it must be getting power and can move.

4) i checked everything over visually top and bottom for obviouse burns or loose wires and everything seems fine. I also tried running a cd in variouse states of assembly to make sure something physical was not preventing the CD from spinning and nothing so i'm led to beleive maybe the spindel is the problem

i should note i own a craftsman multimeter but i have no idea how to use it (or any multimeter)

any help would be appriciated, thanks!

[c0ldb33r]

I'm gonna start with the basics - what AC adapter are you using? Are you using an official NEC one or some Radioshack one? If it's the latter, post the specs.


i should note i own a craftsman multimeter but i have no idea how to use it (or any multimeter)
http://www.wikihow.com/Use-a-Multimeter

[Soviet Conscript]

I'm gonna start with the basics - what AC adapter are you using? Are you using an official NEC one or some Radioshack one? If it's the latter, post the specs.




official NEC adaptor that came with the turbo duo

[SnowKitty]

the CD will not spin unless the laser can see it. try cleaning the lens with a Q-tip and alcohol forst, if that does not help you may need to either recalibrate the old laser or get a new one (electronix.com has em iirc)

[Soviet Conscript]

cleaned duo, lubbed gears, messed with pots, replaced laser

nothing

[FABombjoy]

Some good tips here:
http://www.repairfaq.org/sam/cdfaq.htm

Further repair may require an oscillioscope.

With no disc in place, but the lid switch held down, does the laser eye hunt up & down searching for a disc?

[Bratwurst]

Please tell me this was the system you bought from Tubeway:

http://www.digitpress.com/forum/showthread.php?t=129655

[FABombjoy]

messed with pots
Wait... I see that you pluralized "pots". I hope that's not true. There are 5 adjustments on the board that can take a functional Duo into f'ed-ups-ville in a hurry.


Please tell me this was the system you bought from Tubeway:
Schadenfreude :pimp:

[ProgrammingAce]

Wait... I see that you pluralized "pots". I hope that's not true. There are 5 adjustments on the board that can take a functional Duo into f'ed-ups-ville in a hurry.

It's rather easy to turn it into a Turbo Uno...

[FABombjoy]

It's rather easy to turn it into a Turbo Uno...
Ha!

I intentionally fubared the controls on a Duo once just to see what it took to bring it back. In a nutshell, it took a few days of research, 4 different types of CD, an oscilloscope, a steady hand, and lots of patience. The board adjustments are really finicky - the pots are teensy, single turn, and IIRC most of them are 2k, so tiny adjustments can make a big difference. It's also easy to end up with a unit that reads the inner tracks & then gets AFU on the outer tracks.

[Soviet Conscript]

Some good tips here:
http://www.repairfaq.org/sam/cdfaq.htm

Further repair may require an oscillioscope.

With no disc in place, but the lid switch held down, does the laser eye hunt up & down searching for a disc?

nope. doesn't spin the disc, make any noise or otherwise move. the busy light comes on but thats it. the only time the laser moves is if i put it out of place and then turn on power. it returnes to its start position



Please tell me this was the system you bought from Tubeway:

http://www.digitpress.com/forum/showthread.php?t=129655

yes it is


Wait... I see that you pluralized "pots". I hope that's not true. There are 5 adjustments on the board that can take a functional Duo into f'ed-ups-ville in a hurry.


sorry, ment pot. i didn't mess with the ones on the board only the one by the laser.

[FABombjoy]

nope. doesn't spin the disc, make any noise or otherwise move. the busy light comes on but thats it. the only time the laser moves is if i put it out of place and then turn on power. it returnes to its start position
Check the plugs that connect to the laser. I've noticed that the new ones can feel like they're seated but actually require a bit of force to get fully connected.

If you're laser isn't hunting up and down (attempting to get a focus lock), the problem is probably somewhere between the laser's coils & the servo drive chip.

[Soviet Conscript]

If you're laser isn't hunting up and down (attempting to get a focus lock), the problem is probably somewhere between the laser's coils & the servo drive chip.

in other words its most likely beyond my ability to fix?

[Bratwurst]

Time to send that baby to FABombjoy, or you're looking at an expensive Turbo Grafx 16.