Need help with PSX laser calibration

[m2595]

Long story short - I have a PSX SCPH 7002 (PAL) with a die-cast laser unit, which doesn't read some CDs properly, mostly the non-original ones I have (it is a chipped console, please delete this thread if this is against the rules). It skips, stutters and makes horrible noises sometimes, most of the time with home-made CDs, but sometimes runs trouble free. This problem occasionally occurs with original discs, too. Which makes me think the laser is going bad. I cleaned the lens and the small mirror underneath and greased the mechanism, but it still does all that. Then I tried tweaking the two pots - one on the ribbon cable and one on the motherboard (don't know what that does) by turning them clockwise - things got better, but still not good enough.
Is there some other way to adjust these pots or some other fine adjustment or the only thing I could do is replace the laser? Are those chinese lasers which sell for $15-20 on ebay worth it or are they junk? Should a chipped console with good laser be able to run burnt discs as good as original ones?
Can someone please help?
Thanks in advance!

 

[BobK]

https://www.amazon.com/dp/B003Y3SGHO/?tag=gtplanet-20

Only took a few seconds to find it.

 

[Shaun]

or some other fine adjustment

Try standing the whole unit on it's side, used to work with mine.

 

[Rallywagon]

Try standing the whole unit on it's side, used to work with mine.

Yep, this is how we would get ours working again as well. BTW, no, there is no sorry of calibration you can do to the laser unit. Best to follow Bob's advise and get a new unit.

 

[m2595]

There actually is a way to make things a little bit better and it takes just 2 minutes to do it - remove the top cover and find the ribbon cable running from the laser to the motherboard, there is a small trimmer (laser-side) which can be turned to increase or decrease laser sensitivity. Don't turn the trimmer too much and always mark its original position! It's best to use a multimeter, I've set my laser at 1.35 mV, which, according even to Sony, is perfect. There is a measuring point just above the trimmer, that's where you put the multimeter to read the values. This must be done with the PS running, preferably without a CD installed. There's actually quite a few threads on the internet on how to do it, so I won't fall into details, but it works. Most of the games which previously failed to even boot now play almost troublefree. But I'm still on the lookout for good second-hand lasers or good quality new ones.

P.S: If someone tries this and somehow burns their laser or console - I'm not taking responsibility. Just wanted to point that out.