Some pointers for people who want to try fixing PS2 mobos –
as answer to the topic "lets share technical tips here" I post this:
Check list (sort of flowchart-like but without graphics) for fixing a dead mobo:
1- Disconnect all hacks/mods wires on the board and try to restore it to factory like status.
2- Try to turn it on. At this point some things can happen:
A) Red led doesn't lit. There is a 12v line that feeds a small voltage regulator which supplies power to a chip called "Syscon" (System Controller). It's meant to control the power/eject buttons, monitor the EE temperature and fan speed. If this chip has no power, the PS2 can't be turned on. PS1 is the fuse on this circuit.
B) No Video at all (no video sync, the screen will be blue if the TV has "blue screen" at no sync status).
1st thing for this kind of problem ... check BIOS for short circuit. With a shortcircuit on the bios the IOP cannot start and we don't get the EE/GS initialized. So no video signal at all.
To know if the IOP is alive you need either a osciloscope or Mr. Brown's EE serial cable. If you connect Mr. Brown's EE serial cable to a mobo which have a good IOP but EE ram problem you will see a message like this:
# Init ram returned error : -x (where x is a numeric errorcode)
A healthy mobo will show something like this:
# Initialize memory (rev:3.42, ctm:393Mhz, cpuclk:295Mhz )
# Total accessable memory size: 32 MB (B:2:8:0) (342:3:1280)
# TLB spad=0 kernel=1:12 default=13:30 extended=31:38
# Initialize Start.
... (edited, shows initialization of EE internal devices and the GS)
# Initialize Done.
C) Video comes out but the screen is pitch black (This means the EE memory got detected and the GS was initialized properly)
C-1) You get video, screen is pitch black but eject LED is off. Pobably something is wrong with the Mechacon check if you can eject/close the drive tray, if the laser moves or even if it tries to read discs if you put discs on the PS2. It might have short circuit or broken tracks on the path of the mechacon to the DSP (usually this happen at the modchip install points. check the vias where we install wires A,B,C,D,E,F,G,H and I. Check the 10k resistor at the point A. It breaks sometimes if the wire get pulled and the PS2 sort of get crazy without that resistor). Also, PS14 (In a V4. In a V9/v10 it's PS11) can cause this problem. If PS14 is blown, you're very likely to have to change the BA5815 as well.
C-2) You get video, screen is pitch black and eject led is lit, bright blue. Seems like the mechacom is running but something is wrong still ... Check all modchip install points, check all fuses, check Mechacon for solder bridges.
A faulty/erased NVRAM/Flash may cause this problem on V4 or newer mobos (bios was programmed to don't boot if nvram is empty but older machines do boot without nvram. could not test this on V3s yet)
D) It powers up and goes to the browser (cool you got it working again ! Time to try it assembled to see if it will boot originals )
Last thing.... check these with more attention:
BIOS/BOOTROM, IOP, IOP RAM, Emotion Engine RAM (rambus ram chips), Syscon (in V9, V10 and above the Syscon is part of the Mechacon chip),
Mechacon and all fuses.
Useful tools that can help a LOT on this stuff are
-Multimeter (ohm meter and voltimeter mostly)
-osciloscope (for bus probing and laser adjustments. 20mhz good for laser adjustment ... for bus probing 100mhz is recommended)
-serial converter board (Mr. Brown's one does this job perfectly. Can connect to both Mechacon and EE SIO)
-Windows 98 PC (for Sony mechacon/eeprom crap) anything else can be used
on any PC with a serial terminal program (any OS is good for this)
I hope this post has useful info ....
SCPH-10000_GH-001 SCPH-15000_GH-003 SCPH-18000_GH-008 SCPH-30001_GH-005 SCPH-30000_GH-016(V4) SCPH-30001_GH-010(V4)
2xSCPH-10190, 2xSCPH-10350, 2xSCPH-10280
"**** j0 hackers!"
-Sjeep (As seen on TOXIC OS ELF...)