I just finished the install on a Matrix Infinity chip, with very limited success.
At first it seemed as thought the entire ps2 was dead. Till i learned you could reach the ps2 bios/logo/load screen/whateveryouwannacallit by holding the reset button down for 2-3 seconds.
The ps2 software loads fine, plays movies fine, and I can change all the time and settting options.
However it wont load any games. Be they commercial, backup, ps2, or ps1.
But in the browser, it does infact recognize the fact that its a playstaion disc. Its just that when i select the disc to play it, it stays a black screen of death :(
If I were you I would double check your installation - i.e. make sure al the wires are in the right place, chip is placed in the right place, there is no bridging etc. Or it may be that you have a defective chip.
When you turn on the PS2, does the Matrix logo pop up briefly first? If so, can you enter config menu (circle + triangle) and check the version? Also, if its convenient, high resolution photos of your installation around the solder points might help.
Well done! Sometimes the problem is so easy to fix that it's sad!! I still find it funny though cause you should still be able to play ORIGINAL games even if you haven't flashed the chip - but i guess that it's working now so that's good news.
To find an alternate 5v point, put your ohm meter lead on the original point for the fan, and check some points with the other lead. When you have perfect continuity, that is a 5v source.