Update.
I bough a lot of 4 broken PS1s a couple of days ago so I can have a little fun fixing them.
All units were dirty with busted lasers and various other problems.
I disassembled them and washed cases with hot water and a sponge and left them to dry for a day.
For now I managed to completely fix two units: SCPH-1002 and SCPH-9002.
9002 was in a pretty bad shape. Case was all yellow and there was dried mud
. under the lid.
Controller ports were broken in half and the laser was pretty much dead.
I had another 9002 with a non working motherboard so I swapped the parts around.
The only thing I was short of was a laser assembly. But I discovered something really interesting.
When I rotated the spindle I could hear the slight grinding noise so I though what the hell,
I'll disassemble the motor and regrease it. And that's exactly what it needed.
Seems that over time motor starts to spin slower which is causing read errors, it's not always a laser that's at fault.
I managed to fix another laser unit which I though was long gone. It works awesome now.
So
if you have a broken laser it might just be the motor acting up, regrease it, it's worth a shot.
Be careful not to bend the brushes. There are holes to access them and move them out of the way upon reassembling.
Anyway, I burned a MM3 eur hex to a PIC (12C508A) and installed it inside a 9002.
I also done the color mod (I'm using S-Video and PAL color burst looks so much better), removed the stock serial port
and added wires with DB9 connector.
I decided to replace PSone with this fixed 9002 as my dev unit, here is what it looks like now:
SDK: PSXSDK by Tails92 (20131109) running on Cygwin.
IDE: Notepad++
Console: SCPH-9002 with PSXSERIAL for uploading and testing debug builds.
Emulators: ePSXe, Xebra, no$psx, pSX and PCSX-R (it's a pain sometimes to get the code working everywhere).
Extra: Various 3rd and one 1st party Memory Cards. Clear blue SCPH-110 dualshock controller.
. It is also the messiest looking 
