KMS 440 BAM Calibration

[Mr Rokobot]

Hello everyone!
Today I recovered a PS one but I noticed that the optical unit only reads burned games but not the original ones.
The excellent group is the KMS 440BAM.
How many ohms should I calibrate it to?
I read on the net that for a good reading it should not exceed 680 Ohms.
Could someone give me some tips?
Thank you very much.

[Bluesfire]

Hey there! I would personally advise against messing with the laser potentiometer for now.

More often than not, A PS1 failing or struggling to read discs just needs some basic maintenance and a recap. The laser unit should be cleaned, and it's rails freshly lubricated, followed by replacing all the electrolytic SMD capacitors on the console mainboard.

I struggled for a long time with PS1 repairs as a technician, seemed like no matter what I did I couldn't get most systems reading reliably. I had mastered cleaning and lubing the drives, I had tried new drives, even messing with the potentiometers. While sometimes you can get lucky and make a system read again by adjusting the potentiometer, it is a bandaid fix that only puts more strain on those failing capacitors. It will fail again.

Once I started recapping every PS1 I work on though? Completely different story. I now have a near 100% success rate getting PS1s to read discs reliably, including three personal units. It really makes all the difference. Not only on PS1, but on most early optical media devices. PS1, Gamecube, Dreamcast, etc all need recaps these days for continued reliability.

Hopefully this information helps!

[LouLockman]

Hey there! I would personally advise against messing with the laser potentiometer for now.

More often than not, A PS1 failing or struggling to read discs just needs some basic maintenance and a recap. The laser unit should be cleaned, and it's rails freshly lubricated, followed by replacing all the electrolytic SMD capacitors on the console mainboard.

I struggled for a long time with PS1 repairs as a technician, seemed like no matter what I did I couldn't get most systems reading reliably. I had mastered cleaning and lubing the drives, I had tried new drives, even messing with the potentiometers. While sometimes you can get lucky and make a system read again by adjusting the potentiometer, it is a bandaid fix that only puts more strain on those failing capacitors. It will fail again.

Once I started recapping every PS1 I work on though? Completely different story. I now have a near 100% success rate getting PS1s to read discs reliably, including three personal units. It really makes all the difference. Not only on PS1, but on most early optical media devices. PS1, Gamecube, Dreamcast, etc all need recaps these days for continued reliability.

Hopefully this information helps!

Thanks for the helpful information. Why didn't I see this before. I have been struggling with it for a long time. Now that I have read your article, I will try to remember it so that next time I encounter it, I can fix it quickly and easily.

[MasterLink]

Hey there! I would personally advise against messing with the laser potentiometer for now.

More often than not, A PS1 failing or struggling to read discs just needs some basic maintenance and a recap. The laser unit should be cleaned, and it's rails freshly lubricated, followed by replacing all the electrolytic SMD capacitors on the console mainboard.

I struggled for a long time with PS1 repairs as a technician, seemed like no matter what I did I couldn't get most systems reading reliably. I had mastered cleaning and lubing the drives, I had tried new drives, even messing with the potentiometers. While sometimes you can get lucky and make a system read again by adjusting the potentiometer, it is a bandaid fix that only puts more strain on those failing capacitors. It will fail again.

Once I started recapping every PS1 I work on though? Completely different story. I now have a near 100% success rate getting PS1s to read discs reliably, including three personal units. It really makes all the difference. Not only on PS1, but on most early optical media devices. PS1, Gamecube, Dreamcast, etc all need recaps these days for continued reliability.

Hopefully this information helps!

Yea, with an oscilloscope and experience repairing CD players along with the service manual for my 5501, I found I didn't even have the PkPk range I'm supposed to have before top of the eye pattern would flatten. That's caps going high ESR doing that, and is immediate grounds for a recapping. (And there were NO signs of leakage whatsoever visually, they looked great, so you can't go visually like you can with something say, a Mac Classic which has the same style caps, but clearly are leaking all over the place.)