V1(GH-004)/V2(GH-005) with bios 110 010 are not supported by some low price/mass market mods out there (Mostly Mars series and similar products)
Keep that in mind when trying to fit these mods on such old systems.
Also the mechacon wires (A, B, C,... I) can prove to be pretty challenging on these machines as the vias run under the mechacon and DSP chip, meaning the only way to tap on the mechacon bus is soldering on it's pins. (By this I mean your black screen problems might be a short circuit on the mecha bus pins...) Take your multimeter on continuity test (buzzer one) and measure A with GND and +3v then measure B to GND and +3v. And finally check b to c, and h to i for short circuit with it's neighbours pins. If there is a short circuit on the mecha pins you will get a nifty black screen.
Btw I own a US V1 with bios 010 (gap type. there are 010s no gap too but they're rare) and it runs incredibly well with a original Matrix mod. I don't know the duo chips so I can't say if this one support the US 010 bios
thought. If you install a mod into a machine and the specific bios on the machine is not supported by the mod you get weird stuff like it trying to boot then going back to browser or just RSODs, regardless of the mod being properly wired or not.
I hope this was helpful
hint: to indentify the version of the bios on your US PS2 you can do this:
At the browser screen press triangle. A US PS2 with bios 010 will have DVD driver 1.10U. 020 will have 1.20U and 030 will have DVD driver 1.30U. Some V4s have bios 040 with DVD 1.30U (Bios 040 is only seen on GH-013 and V5s) anything up than 020 is well supported by the majority of mods out there.
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...)