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CD-ROM² calibration

Started by Ergot_Cholera, 08/21/2016, 04:52 PM

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Ergot_Cholera

There are guides and advice one Duo and Super CD-ROM² laser calibration but not for the sorry old CD-ROM² unit.
Please help!  :cry:

Vimtoman

#1
Picture of my settings

IMG

I tend to start with setting the pots up using it then tweak.

If you find it a problem and you've done a clean and a complete cap change then it's the laser.



Ergot_Cholera

I appreciate the input but I need help with CD-ROM²(not Super CD-ROM²).

Vimtoman

Sorry about that wrong image.

CZroe

Quote from: Vimtoman on 08/22/2016, 09:03 AMSorry about that wrong image.
So, the image we see now is correct? Looks like it. :)

Thanks.

Next question: do we just follow the Duo or Super CD-ROM^2 adjustment guides? Do the components labels (VR1, VR2, etc) correspond to the same adjustments in each?

fluxcore

from: https://console5.com/wiki/Turbo_Grafx_CD-ROM_Drive

"From left to right, PCB facing down. Note the out of order numbering.

VR101 - E/F Balance (CXA1081, pin 12, 13)
LASER CONNECTOR
VR102 - Focus Error (FE) / Focus Offset Bias (CXA1081, pin 18)
VR105 - VCO (CXA1082, pin 30)
VR103 - Tracking Gain / Tracking Error (CXA1082, pin 45)
VR104 - Focus Gain / Focus Error (CXA1082, pin 48)"

I believe the turbo grafx cd is equivalent to the cdrom2...
There is no knowledge that is not power

CZroe

#6
Quote from: fluxcore on 01/03/2018, 04:07 PMfrom: https://console5.com/wiki/Turbo_Grafx_CD-ROM_Drive

"From left to right, PCB facing down. Note the out of order numbering.

VR101 - E/F Balance (CXA1081, pin 12, 13)
LASER CONNECTOR
VR102 - Focus Error (FE) / Focus Offset Bias (CXA1081, pin 18)
VR105 - VCO (CXA1082, pin 30)
VR103 - Tracking Gain / Tracking Error (CXA1082, pin 45)
VR104 - Focus Gain / Focus Error (CXA1082, pin 48)"

I believe the turbo grafx cd is equivalent to the cdrom2...
Yes. Only difference inside seems to be a wire to ground the shielded bottom (presumably for US FCC compliance). I'll see if this info allows me to follow one of the other adjustment guides when I get back to it. Thanks!

Edit: ...and now I've seen a video of an "older" PC-Engine CD-ROM^2 with a ground wire soldered to the bottom shield. Guess the biggest difference really is cosmetic (window on top).

waynedoodle

If my music is dropping out (and slow CD-R load) which pot should I adjust?  Also, should an increase in pot be clockwise or counterclockwise?

I love my CD I've had since 92, gear was replaced but I think my twin brother tinkered with the pots a long time ago in college when the CD quit (unknown gear failure).  Games mostly work but I get music dropping.

Keith Courage

These drives are not really made for CD-R discs. They were made before CDrs existed. With this in mind you might be able to make some adjustments to get them to read better and you might not. Also the brand of CDR media can have a major effect on this as well. I would try other brands first before making adjustments. Some drives may work good with many brands whereas some drives might only work well with generic media such as Verbatim or Memorex and other drives might require better CDRs like Sony or Taiyo yuden. I've come across many drives that will refuse to read a specific brand but work perfect with another.

robotype

Quote from: waynedoodle on 02/25/2018, 12:00 AMIf my music is dropping out (and slow CD-R load) which pot should I adjust?  Also, should an increase in pot be clockwise or counterclockwise?

I love my CD I've had since 92, gear was replaced but I think my twin brother tinkered with the pots a long time ago in college when the CD quit (unknown gear failure).  Games mostly work but I get music dropping.
I just recapped a cdrom2 and has the same problem, music drops and it's very sensible to vibrations (I am using original discs only)

I'd like to know which pot is most likely the culprit.

This is the resistance values on my pots on a good working unit fully recapped

pot 101 (e/f balance) = 9.4
pot 102 (focus offset) = 0.4
pot 103 (track gain) = 17.0
pot 104 (focus gain) = 17.1
pot 105 (vco) = 19.3

so I adjusted the faulty one to the same values but it's still very weak.

Keith Courage

Quote from: robotype on 05/10/2018, 05:43 AM
Quote from: waynedoodle on 02/25/2018, 12:00 AMIf my music is dropping out (and slow CD-R load) which pot should I adjust?  Also, should an increase in pot be clockwise or counterclockwise?

I love my CD I've had since 92, gear was replaced but I think my twin brother tinkered with the pots a long time ago in college when the CD quit (unknown gear failure).  Games mostly work but I get music dropping.
I just recapped a cdrom2 and has the same problem, music drops and it's very sensible to vibrations (I am using original discs only)

I'd like to know which pot is most likely the culprit.

This is the resistance values on my pots on a good working unit fully recapped

pot 101 (e/f balance) = 9.4
pot 102 (focus offset) = 0.4
pot 103 (track gain) = 17.0
pot 104 (focus gain) = 17.1
pot 105 (vco) = 19.3

so I adjusted the faulty one to the same values but it's still very weak.
You are going to have to do the adjustment via process of elimination. Just make an adjustment to one of them and then test the drive. If things don't improve then put the settings back to where they were and try another potentiometer. This is how I do it and I've been repairing these for years. 

robotype

Quote from: Keith Courage on 05/10/2018, 06:20 AMYou are going to have to do the adjustment via process of elimination. Just make an adjustment to one of them and then test the drive. If things don't improve then put the settings back to where they were and try another potentiometer. This is how I do it and I've been repairing these for years.
yes that's what I was doing but I noticed even very small increments make a difference, so it takes a while to figure out.
I was wondering if this could be a "typical" fault than can be solved with standard adjustments. thanks for the suggestion anyway.