CD-ROM² Potentiometer Reference Images

[Popinadam]

Howdy folks,

  Picked up a faulty CD-ROM² drive. Need some reference images of the potentiometers so I can get a baseline of where I should start. The one I received had them all turned to one side. I've played a little bit around with it myself and have gotten it to spin up at one time but never could get it to read the disc.

   If anyone can post up a quick photo of their working units POTS I'd be super grateful. Thank you! Might help some other people in similar situations.

[LowRes]

Howdy folks,

  Picked up a faulty CD-ROM2 drive. Need some reference images of the potentiometers so I can get a baseline of where I should start. The one I received had them all turned to one side. I've played a little bit around with it myself and have gotten it to spin up at one time but never could get it to read the disc.

   If anyone can post up a quick photo of their working units POTS I'd be super grateful. Thank you! Might help some other people in similar situations.

https://console5.com/wiki/Turbo_Grafx_CD-ROM_Drive#CD_Adjustments

give this a read, if I get a chance I'll take mine apart tomorrow and take a pic of the pots for ya.  Adjusting the pots on the Duo and Duo-R was much easier for me since you can do it live and adjust it by ear following the guide on here.

[MNKyDeth]

In the cdrom adjustment pots guide on this forum I think it was around page 8. There is a post that specifies specific good values that work for nearly all of the units as a base value to start at. Don't even need an oscilloscope for it just a regular volt meter to do it and start from a good value.

[Vimtoman]

I posted an image of mine on this thread.

TG/PCE Repair/Mod Discussion / Re: CD-ROM² calibration

[Popinadam]

   Alrighty, so I had some success! I started off with Vimtoman's photo which got me back to disc's spinning but not reading. Got the "Please set Disc!" error...

   Then I followed up with the guide LowRes posted. I used an audio disc, removed the cdrom2 from the briefcase and plugged in power and headphones directly, flipped it upside down and started making some minor tweaks to the pots until the audio wasn't garbled anymore. Tested the skips and everything seemed to be operational. Popped in a disc of Dungeon Explorer II and sure enough it fired up.

   The biggest improvements came from the 102 pot. I could literally hear the audio clearing up in real time while I tweaked it. I can't tell if it's 100% perfect because I don't have any other experience with pc engine disc games to compare but this was leaps and bounds better than staring at an error screen and having a non spinning drive.

   I had to search for "calibration" to find Vimtoman's photo of the potentiometers in case that helps anyone in the future. Maybe someone can add it to the calibration guide or sticky it somewhere. It's a great starting point. Thanks for everyone's help!

[LowRes]

Alrighty, so I had some success! I started off with Vimtoman's photo which got me back to disc's spinning but not reading. Got the "Please set Disc!" error...

   Then I followed up with the guide LowRes posted. I used an audio disc, removed the cdrom2 from the briefcase and plugged in power and headphones directly, flipped it upside down and started making some minor tweaks to the pots until the audio wasn't garbled anymore. Tested the skips and everything seemed to be operational. Popped in a disc of Dungeon Explorer II and sure enough it fired up.

   The biggest improvements came from the 102 pot. I could literally hear the audio clearing up in real time while I tweaked it. I can't tell if it's 100% perfect because I don't have any other experience with pc engine disc games to compare but this was leaps and bounds better than staring at an error screen and having a non spinning drive.

   I had to search for "calibration" to find Vimtoman's photo of the potentiometers in case that helps anyone in the future. Maybe someone can add it to the calibration guide or sticky it somewhere. It's a great starting point. Thanks for everyone's help!

so you flipped the unit upside down while playing an audio cd and you were able to adjust the pots live listening by ear? very cool.  I didn't think you could do this kind of method with the original cd-rom2 but now I learned something new

for further tweaking down the road if you have issues with certain games not working, I've had better compatibility after tweaking my pots while playing the last track of a audio cd.  I think I read that tip on here somewhere probably in the duo/duo-R guide.

I'm glad you're up and running!

[fluxcore]

Here's the post with the image btw, was a pain to find. https://www.pcengine-fx.com/forums/index.php?msg=468763

My CD-ROM² doesn't really like CDRs unfortunately. Games will load and play, but the music drops out. It'll play audio CDs (or the audio on the game disc) absolutely fine all the way through, and also will play later tracks (say, 12+ on lords of thunder's music menu) fine, but early tracks will drop out.

I've buggered around with the potentiometers for hours and can't get it to solidly keep playing the early tracks.

CDRs are Verbatim AZOs (although have also tried other brands), and have tried a number of writers and speeds.

Weird that people seem to talk in general about issues with later tracks rather than early tracks though.

[ginoscope]

You probably just need a new laser.  I had issues reading cd-r on my turbografx cd when I originally got it.  I bought a cheap discman and took the laser out and after adjusting the pots slightly it reads cd-r just fine.  There are still some games that have issues but not that many.