I installed the green dot Matrix Infinity (the new ones) in a V3.
This worked and could change the config settings.
PS2 backup games on DVD-R and DVD+R could be played.
Upgrading to 1.75 could only be done by holding the reset button until the blue light was seen.
When the upgrade finished, PS2 backup games on DVD-R and DVD+R could not be played.
Also I could not access the config menu.
Reinstallation of the 1.75 firmware, did not solve the problem.
So my conclusion was from that point, the 1.75 firmware is not compatible with V3's.
I only tested with 1 green dot MI chip.
Solution in that case, was to remove the chip, and install a new MI, and tell the owner not to upgrade to 1.75.
But, when I used the old chip in a V7, the chip did not work with the 1.75 firmware.
Reinstallation of the 1.75 firmware solved the issue.
In both cases, all the solder points were double checked.
So my conclusions could be:
1) The 1.75 firmware is not compatible with SCPH-30004 (PAL V3).
2) The 1.75 firmware could not be loaded on the MI (green dot) successfully (by whatever reason).
Has anyone seen this before ?
Also with V12/V13 I had to hold select button, in order to upgrade the green dot MI to 1.75.
Also the new MI is not working in a HK NTSC version SCPH-39006.