Guess who’s back, back again?
During last few months my life has changed 360 degrees for the better. Yes, I know, nothing changed, I still love my retro PCs, especially fixing them. I do have a bit less time for them, that’s all.
So, today we’re going to break a PS1 CD drive.
I believe You know this console already, I tried to use an oscilloscope to fix its laser, but to no avail.
Recently I’ve asked myself: “OK, so the chinese drives are unusable at worst and trash at best, what can I do to get my PS1 working again?”
And then I got the idea.
What if I swapped the laser diode only?
OK, OK, I know what You’re thinking, it’s not only the diode that goes bad, it can be worn gears, slightly demagnetized magnets in the optical pickup module, blah blah blah…
In this particular case the laser itself was so worn that any adjustments wouldn’t improve it at all. So I decided to swap it.
OK then, I know what to do, but how do You even get a laser diode, and how do you know even IF it’s going to work?
That’s the neat part, I don’t know.
I searched the web for similar lasers and found 2, one I don’t remember and the second one, KSS-540A.
You can’t swap the pickup assembly – coils, lens…, but the diode seems fine to do a swap. I bought a “new” one, but to be honest I have my doubts if it’s NOS.
Anyway, time to disassemble the playstation.
As You can see, direct replacement is not an option.
Removing the plastic cover was easy enough, however the plastic gear was ABSOLUTELY STUCK there. I eventually managed to remove it, but all that time I was worried I was going to break it.
Both lasers taken apart. I’d love to swap that pickup assembly, but no can do.
OK, this is the main part of this repair. Right is KSS-540A, left is KSM-440AEM. I need to swap these diodes. They are mounted with a bit of epoxy, which I obviously don’t have and will need to improvise there, but other than than You just desolder the flex PCB and swap them.
By the way, these ICs are really cool – it’s a laser diode, diode detector and power monitoring diode in one package.
Anyway, back to the repair. The replacement itself is pretty simple, the soldering is difficult though – You have something that You can’t touch (laser window and finger grease don’t mix well), is a bit sensitive to heat, very small and on a floppy PCB.
I eventually managed to solder it back together. As I mentioned previously, I didn’t have epoxy, so I used a thermoconductive glue – the only sticky thing I had in my cave.
Okay, maybe besides electrical tape, but my point still stands.
Time to put it back together.
Time for a test.
I still can’t believe it. IT WORKS! I obviously had to tinker a bit with the oscilloscope and adjust the power potentiometer, but it works all the way from 600mV p-p. Manual asks for ~900mV, so that’s what I adjusted it to.
Boy, does it work good – every game, even backups work first try, every try. It’s like this console is brand new. And that’s probably as close as I’m going to get to a new PS1.
Thanks for reading!