Help a noob to calibrate pots for CD-R reading

[Punch]

Ok, my US Turbo Duo has the following problems when reading CD-R discs:

1- Cannot seek far tracks (jams laser with audio CD, when playing Ys1+2 when freeing Feena from the prison at the beggining)
2- SuperCD backups will skip audio tracks during gameplay (i.e. abrupt stopping the music).

Retail discs are OK.

I've searched all over the forums what to do but since I'm dumb I still don't know what to do. What pots do I need to adjust, how to measure adjustments? Do I mess with the pot from the laser itself? What games should I have to test the console?

Any help would be appreciated.

[blueraven]

Look here.

It's the trim pot adjustment guide, which is the second part of the Laser Swap guide. If you read through the thread in its entirety you will find some tips and tricks that will help you through this. there is some incredibly useful stuff in the last 5 or so pages that will also be added to the second post...

If you have any more repair questions after reading the guide, or want to post your results there, we would all appreciate it

...and Good Luck

[Keith Courage]

Usually making minor adjustments to the V102 or V101 can help. V103 might also do some good but the V104 and v105 rarely ever have to be adjusted. So leave those two alone. However, make sure to keep track of where you started to put things back the way they were just in case.

Also, please keep in mind. Sometimes in rare cases no adjustments of any sort will fix some systems issues with CD-R discs.

[Punch]

OK, I got some super cd games to load finally, but it still refuses to load later tracks. I can hear feena's speech now! Adjusted V102 and V101. I couldn't get it any better than my current results, I might play around later when I get access to a oscilloscope.

[blueraven]

Keith is totally right.

Have you replaced the laser on this system?

[Punch]

Keith is totally right.

Have you replaced the laser on this system?

That's a good question, I'll have to ask Agent Orange aka Galam about it, he's the one who sold the duo to me. AFAIK it was at least cap replaced by Keith Courage.

I just messed a little bit more and I managed to make It Came from the Desert to play glitchless... well at least most of the time, sometimes it does glitch out, but it's miles better compared to how it was. I really need an oscilloscope for this don't I?

I might buy an actual copy of It Came from the Desert to see if it is the same with a retail copy.

[Keith Courage]

I recapped the system for you before? I must have tested out the CD drive for a while before sending it back to you. I can't remember if I tested with CD-R discs since I do most of my testing with real ones.  Were CD-R discs an issue as soon as you first got it back?

Also, does the system have a region switch installed? Some DUOs can have issues with CD-R discs is an 8pDT was used for the region mod. The routing of the wires for it cause the glitches.

[Punch]

I recapped the system for you before? I must have tested out the CD drive for a while before sending it back to you. I can't remember if I tested with CD-R discs since I do most of my testing with real ones.  Were CD-R discs an issue as soon as you first got it back?

Also, does the system have a region switch installed? Some DUOs can have issues with CD-R discs is an 8pDT was used for the region mod. The routing of the wires for it cause the glitches.

You did recap it but it was through Galam, I bought from him already recapped, never asked about the CD drive though. No region mod.

[choijimmy]

My 2 cents,

1. Try to burn the game with good cdr brand like Sony, tdk with lowest speed eg, 8x

2. I used to have cdr issue for some duo-rx, no matter how I tune it, it is still unable to read cdr, well, may be it works for few games but most of them are not. However, retail pressed games are perfectly fine. The root cause for my case is due to weak laser, once I replaced the laser lens, everything resolved.

[NightWolve]

Steve has a video around for professional adjustment of those pots using an oscilloscope if you ever wanna go that far.

A cheap oscilloscope solution is to buy a $60-$110 USB model and $35 Windows tablet since the software is usually built for Windows and not say Android.

I bought the 40Mhz SainSmart scope for $90 after negotiating the seller down, but he has $60 20Mhz models for sale:

http://www.ebay.com/itm/SainSmart-DDS120-Pro-20MHz-PC-Based-USB-Oscilloscope-/

[Vimtoman]

I'm interested in the video.

[MNKyDeth]

Steve has a video around for professional adjustment of those pots using an oscilloscope if you ever wanna go that far.

A cheap oscilloscope solution is to buy a $60-$110 USB model and $35 Windows tablet since the software is usually built for Windows and not say Android.

I bought the 40Mhz SainSmart scope for $90 after negotiating the seller down, but he has $60 20Mhz models for sale:

http://www.ebay.com/itm/SainSmart-DDS120-Pro-20MHz-PC-Based-USB-Oscilloscope-/

Not knowing much about Oscilloscopes much myself would that model be more than enough if all you were using it for was calibrating cd-rom pickup lens with it?

I thought they would be more expensive than that. Hence why I never bothered looking for one. it would be something else for me to learn to use too. And that could be fun.

[NightWolve]

The principle goes something like this: you need (preferably) 4x the MHz ability in the scope than the signal you'll be analyzing for best viewing results.

Take traditional analog TV video signals (like what our retro consoles output), they range up to 6 Mhz, thus 6 x 4 = 24, so you could get by with a 20Mhz scope, but 40Mhz is better. No need to go more expensive to a 100Mhz scope and on though, etc.

Steve's video was posted on Facebook, so ask him or wait maybe if he possibly sees this thread. Also, I don't know the signals involved when it comes to those CD potentiometers, so that question would have to be answered by him.

[Vimtoman]

I can get a scope just need the info.

I'm guessing P5 on the super cd-rom is the connector to use with a scope but dont you need some sort of test cd for this?

[NightWolve]

Whad'ya know, I found Steve's video link.

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Unhide all the comments, and you'll get more info on how to perform this test. That's me in the comments with Steve, cause you have to probe him to get useful details.