Tried it and no dice. It will boot in B/W in both PAL and NTSC mode. I checked the wiring and it's done correctly.

Maybe it's because I have a early PU-8? I know the S/N on the board ends in -467-11, and at least I couldn't find the 0 ohm links for the main 53MHz XTAL.

I've been doing some research lately now that I have a PU-8 machine on my hands (chipped before I got it and came with a US supply despite being a PAL machine, beats me why did that happen) and found this on Youtube. Anyone can explain if this would work? Might be a way to do the mod without a speci...

You can do that on the underside of the board too.

Okay so I've went over an diagram of the PS1 BOOT ROM. In theory I could use any PLCC EEPROM that's erasable - the only thing I'd need is VCC points for the EEPROM since I don't have any MB that uses a 5v EEPROM, thus the need of a 3.3v point on the PS1 board. I'm going to buy another PS1 (I only ha...

Although not a whole flashable replacement, I just soldered in a SCPH-5502/5552 BIOS on my 9002. I used a paperclip to gently push the pins out of where they were soldered, and didn't rip any pads! Soldered the replacement SCPH-5552 BIOS on my 9002, checked that I soldered the pins right. Fired up m...

Though I didn't realize Japanese consoles wouldn't allow region free with MM3. That's disappointing. I assume this is a limitation of the early PS1 models? Is there any way around this? I have an NTSC-J PSone, modded as well but not by me, and that model plays other regions. Apparently the NTSC-J P...

K4DoS: Go check the PsNee development thread! I just got the PSOne BIOS patch working and it will also patch your 7502 console. You will effectively have an "NTSC" BIOS then. The PAL and NTSC BIOS only differ by a few bits, one of which the mod patches. Thing is, I don't have an Arduino :...

I actually just want to do that for fun. It's going to be chipped with a classic 4 wire chip though. So it's going to generate PAL60 on bootscreens and menus? Sounds like what the ONECHIP for the slim PSOne does. Initially I was going to try this on a 5552 but I gave up after finding out the XTAL pr...

I just came back to thinking about this - I am still not sure - will I need to replace the mechacon and X201? (the 17MHz XTAL present on all PAL boards) I want to get a 7502 or a 9002 and flash the NTSC-U counterpart BIOS on a flash chip and solder it in just to see if it works.

Now it's not clear which kind of oscillator or resonator you used in your mod. Also it's not clear whether you used a driver, in case you went with a resonator. The PIC in the original mod is used as driver ( I guess. I can't imagine what else it should be good for. ) In any case, you obviously nee...

So I've seen the NO$PSX thread and the replacement ROM being a SST 29EE020 (of course it's probably possible to substitute it for the correct 512K ROM, assuming it runs on 5VDC). Now here comes my question: Will this method work for replacing the BOOT ROM in a PSone (or grey PS1) with a BIOS of your...

Actually, I don't have that PIC installed in my PS1. That was just a diagram of what is required to make that PU-7/8 & PU-18 mod. I tried finding a 4 pin 4.43MHz oscillator but no dice in my town. Only 4MHz. And the wire I disconnected is the one that goes to Pin6 on the CXA1645M chip. (so SCIN ...

Although old, I have tried the PU-18 colour mod made for CXA1645. IT DOES NOT WORK. I don't know but I I've rechecked my wiring at least 20 times over 4 days. The QXO-1100 was replicated using a 4.43MHz 2 pin XTAL with two 20pF disc capacitors and a 2.2K resistor for the frequency wire. Result: PAL ...

Yes,but the one that uses a wire to connect pin 157 to GND through a wire is easier if you have a 40W or higher soldering iron.
If I would have tried the method in the first picture I would have ended up with a dead 7502 board.
Still,what happens if the same mod is done on a NTSC 7501?

Shadow,I checked your picture against another colour mod picture I found,and I came to the conclusion that the mod can be done in another way. Just lift pin 157 and then solder a link between 2 points,as in this picture: http://www.psxdev.net/forum/download/file.php?mode=view&id=312&sid=f17b...