Laser calibration/fix PlayStation 1 KSM-440BAM

Can some one help me with the correct values (range) for this kind of lasers?
I don't know how to measure them to see if they are very used/worn out or not.
I know that the values must be expressed in ohms and I know where is the potentiometer for the laser but I don't have other knowledge.
Thanks!

 

Apparently the sweet spot is 900-800 and don't go lower than 600, so basically turn as little as possible to achieve no skipping/disc not booting.

Mine are around 8-900 and boot the cheapest media although it's abit depressing how many ps1's I have to tinker with.

This information is from the web and youtube so do at your own risk lol.

100x and not sure about the PSOne have 2 more adjustments if you get stuck I'll try and find the video not sure if I can share links.

 

I've asked this question for SCPH-102 consoles because those I have.
In principle should be the same method for PSone.
Thank you!

 

Without an oscilloscope you shouldn't adjust the laser intensity (the only potentiometer to tweak on a PSOne).
If it skips FMV or doesn't read games well, the problem is more likely to be read head misalignment. Tweaking the laser intensity has very little effect on it, if at all.

 

Rama and how to repair the head misalignment?
Thanks!

 

I've been having issues getting backup copies to load on my chipped SCPH-1002. I've tried a cheap KSM-440BAM replacement from China, I've swapped in the laser from a SCPH-5502 (modified to fit), used Verbatim CDs and tried a couple of minor pot adjustments on each.

I can get official games to work no problems and sometimes my backup of Thrill Kill very occasionally, but all others won't get past the black Playstation splash.

 

Try adding a decoupling cap to the modchip

 

Have you just had the chip installed? i did a mayumi v4 on a pal just for fun but it gave weird issues, would only boot certain brand cd backups I had 2 different ones both cheap, tried all the same backups on another ps1 and they all booted, switched the laser from the one reading them and still would only boot certain discs sometimes, but the originals ran fine.

chips read and verified,kept the oscal although not needed for mayumi v4 in the end after redoing some wires and trying mm3 I got perfect results with mm3 and the same laser read anything thrown at it

Edit - mine didn't go to the splash screen with the ones it wouldn't read,sometimes cd error and sometimes to the music player.

 

I bought the PSX second hand, so I don't know when it was installed, so anywhere from a year to many years ago. Will have to look into its installation closer when I'm finished work.

 

But my big question is: the laser diode can be measured with a multimeter to see it it's used/worn or not?

 

That's the million dollar question, isn't it
I use my own method of adding material to the read head sled and it works sometimes. If it works, the fix is pretty good (it keeps working after a couple months).

 

I have never seen a truly worn out laser diode on a PSX. Only dirty lenses and nicotine on the mirror / diode..

Edit: Also, most drives I look at are from the earliest 1002 consoles from 1995

 

Hm, I understand.
Can bad capacitors influence the laser reading discs?

 

I suppose so but I don't know how far. Unless they're totally bad, the nature of the thing is that it's a constant feedback loop. It should work even with degraded capacitors. Might have less room for correction though.