PS1/2 Repairing and modchip a PS One?

SylverReZ · May 15, 2023

Fien said:
I have a MultiMode3 installed now because I only had a spare 12F629 PIC at home. The Onechip code is not available for 12F629 and the 12C508A is difficult to buy in The Netherlands.

PSNee needs other chips for which I don't have a programming device and it's not very well documented.

With the MM3 I can play PAL backups, out-of-region stuff needs the softmod.

Try looking on eBay or AliExpress for 12C508 chips. The best thing about the ONEchip is that it allows you to boot games with a modified logo or license text on unlicensed and/or custom discs since Sony patched those measures out to curb piracy.

KleinesSinchen · May 15, 2023

Fien said:
The cap really seem to repaired it.

That is surprising and good to know. One thing more to keep in mind.
Never had guess this issue. Thanks for sharing your solution.

benone · May 15, 2023

Wow! you did it Fien.
great job out there!

Fien · May 15, 2023

It was someone that let me watched this video before I thought about bad capacitors. That unit in the video had bad capacitors in the video output (and a bad power supply). So I'm afraid bad caps aren't uncommon in PS Ones.

benone · May 16, 2023

Interesting video, I watched it all!

Fien · May 25, 2023

This PS One still works fine after hours of games.

Yesterday I wanted to replace the ugly 2x 1uF capacitors in series (which I putted there for test) with a new 0,47uF/50v SMD cap like how it was original, but it turns out CD reading was getting worse (skipping FMV and audio, frequently not booting) with that one

Adjusting the laser pot didn't make it good as it was. So I end up putting back the 2x 1uF caps in series and turning back the pot to the working value. I don't know why it's bad with a new cap of the original value. Maybe this is a case of "if it ain't broke, don't fix it"

And there's another weird thing with this PS One, I think it's (MM3) modchip related: if the unit is unused for some time (cold), most of the time backups need a second boot to start. The first boot it's detected as audio (game with CDDA) or the red screen. But this second boot can just be a quick power cycle. After plugging in the power it's enough to press the power button ON-OFF-ON within a second and backups boot fine, I don't need to let it booting, failing and reboot.

Originals boots fine every first time, even when the console is not played for days. So it feels like it's the modchip not injecting the SCEE at the right time when first boot after for some time unused.

This doesn't happen when it's used, like changing to another game.

master801 · May 25, 2023

Fien said:
Yesterday I wanted to replace the ugly 2x 1uF capacitors in series (which I putted there for test) with a new 0,47uF/50v SMD cap like how it was original, but it turns out CD reading was getting worse (skipping FMV and audio, frequently not booting) with that one Adjusting the laser pot didn't make it good as it was. So I end up putting back the 2x 1uF caps in series and turning back the pot to the working value. I don't know why it's bad with a new cap of the original value. Maybe this is a case of "if it ain't broke, don't fix it"

An SMD aluminum electrolytic cap?

The only thing I can think of that would cause something like that would be either a bad cap (whether made by a questionable manufacturer or just plain luck - although rare) or bad ESR / ripple. Although this is just speculation.

Fien said:
And there's another weird thing with this PS One, I think it's (MM3) modchip related: if the unit is unused for some time (cold), most of the time backups need a second boot to start. The first boot it's detected as audio (game with CDDA) or the red screen. But this second boot can just be a quick power cycle. After plugging in the power it's enough to press the power button ON-OFF-ON within a second and backups boot fine, I don't need to let it booting, failing and reboot.

Originals boots fine every first time, even when the console is not played for days. So it feels like it's the modchip not injecting the SCEE at the right time when first boot after for some time unused.

This doesn't happen when it's used, like changing to another game.

Common issue with the MM3 is the timing going out of sync with the console.

The biggest problem with MM3 chips is how they base their timing on the internal oscillator within the PIC chips. Using the internal oscillator can sometimes cause the chip to become out of sync with the console when booting, meaning you’ll have to restart the console to boot.

Certain PIC programmers can also mess up the internal oscillator value when programming, which could be a problem if you are programming your own chips. Additionally it has been reported that certain batches of PIC chips have had problems with the oscillator value in the past.

Source: https://quade.co/ps1-modchip-guide/mm3/

imo Mayumi v4 (if compatible with the motherboard) is a bit more reliable than MM3 since it doesn't rely on internal timing (if also wired properly...)

Fien · May 25, 2023

master801 said:
....
Common issue with the MM3 is the timing going out of sync with the console.

I already was afraid of this

So this can happen any time when the console is unused for some time? Previously I installed one in a SCPH-5552 and that one always booted backups directly.

The MM3 was the only choice because at the time I installed it, I only has a spare 12F629 PIC. If I had a 12C508A I would use OneChip so it can boot import backups too.

After that I've ordered 3 12C508A's hoping to make a OneChip but overlooked the pictures. It arrived as SMD parts yesterday instead of DIP-8. Maybe I'll try to use it.

master801 said:
An SMD aluminum electrolytic cap?

Yes.

SylverReZ · May 25, 2023

Fien said:
After that I've ordered 3 12C508A's hoping to make a OneChip but overlooked the pictures. It arrived as SMD parts yesterday instead of DIP-8. Maybe I'll try to use it.

Both SOP-8 and DIP-8 parts will work.

Fien · May 25, 2023

SylverReZ said:
Both SOP-8 and DIP-8 parts will work.

I know, but my programmer only has a DIP socket

And it will require very small soldering to get it installed.

SylverReZ · May 25, 2023

Fien said:
I know, but my programmer only has a DIP socket And it will require very small soldering to get it installed.

Best to buy those SOP-8 to DIP-8 adapters, I highly recommend it.

Fien · May 25, 2023

Those adapters are only available at China which takes 4-8 weeks to deliver

I don't want to wait so long and just programmed it with wires soldered on it and pushing these tinned wires in the programmer socket, it worked

But, with OneChip the PS One boots very bad

Backups needed 2-3 reboots before it loaded to the SCEE screen. Then sometimes it got stuck there forever or needed 10 seconds before the game loaded. Even when the console was warm. I didn't think is was the wiring, I used the same wires as for the MM3 (including short pin 6 wire).

I ended up restoring the MM3 into place and only use the BIOS-patching part of OneChip. That's working good now

Both PAL and NTSC US/JP backups boots directly. The console starts in "NTSC" mode, in RGB the colors are fine, for composite I did the color fix (http://www.fatcat.co.nz/psx/install/102/pm41_2cfd.html).

So, this PS One has 2 modchips in it now

SylverReZ · May 25, 2023

Fien said:
Those adapters are only available at China which takes 4-8 weeks to deliver I don't want to wait so long and just programmed it with wires soldered on it and pushing these tinned wires in the programmer socket, it worked

But, with OneChip the PS One boots very bad Backups needed 2-3 reboots before it loaded to the SCEE screen. Then sometimes it got stuck there forever or needed 10 seconds before the game loaded. Even when the console was warm. I didn't think is was the wiring, I used the same wires as for the MM3 (including short pin 6 wire).

I ended up restoring the MM3 into place and only use the BIOS-patching part of OneChip. That's working good now Both PAL and NTSC US/JP backups boots directly. The console starts in "NTSC" mode, in RGB the colors are fine, for composite I did the color fix (http://www.fatcat.co.nz/psx/install/102/pm41_2cfd.html).

So, this PS One has 2 modchips in it now

This is what I mean, you can find packs of them on eBay and Ali. You attach the chip to the adapter and then solder the wires from the mobo to the adapter.

Fien · May 25, 2023

Yes, I saw those and eBay/Ali is... China... which takes really 4-8 weeks to arrive

Sometimes there're German sellers but those costs more then all 3 chips together.

But now I used it without adapter. I think the adapter only won't make OneChip boot better.

SylverReZ · May 25, 2023

Those wires though on pins 3 and 4 of the chip can short if they go together. I recognise the same wire that you use on my modded PS1 which had an Old Crow installed.

Fien · May 25, 2023

I've make the wires a little bit shorter/cleaner.

They were messy because first I repositioned the chip multiple times, even twisted it upside down ("deadbug") once.

The wires are stripped flatcables, I have a lot of them from other scrapped devices. The drawback of them is that the isolation smelts very quickly when soldering, within 2 seconds.

The Real Jdbye · May 25, 2023

Fien said:
I was given a defective PS One (PAL, SCPH-102, PM-41 board) which didn't read discs at all. It somehow work with original games after lubricating and "pot tweak" the laser unit. But it's weird, some games only boot sometimes or after another game if I let the console rest for some hours. Like Crash Bash always boots, but Bugs Bunny Lost in Time only sometimes and after Crash Bash is played. And Bust-a-Move 2 most of the time is detected as audio CD instead of a original game.

Then I tried to get backups working. Because I only have a spare 12F629 PIC I programmed a MultiMode3 modchip. So far I understand the MM3 used on a PAL PS One (SCPH-102) should work, but only for playing PAL backups because of the region lock in the BIOS? But I can't even get PAL backups to work. Some are detected as audio CD's (like Tekken 3, WipeOut 3, Spyro) and some give the red screen with "Insert PlayStation format disc" (like Crash Bash). I checked the modchip connections matching this one (https://quade.co/ps1-modchip-guide/mm3/pm-41/) and no short circuits.

Is the modchip not working or is it only a worn CD drive problem?

Generally speaking, a pot tweak is only a temporary imperfect fix for a failing laser. There's only so much you can do to improve things if the laser is failing, so this sort of behavior is not uncommon.
The real fix would be to buy a replacement laser assembly, but it could get expensive considering the things haven't been manufactured for decades.

Fien · 2024-11-14T18:56:56+0000

This PS One still works

Meanwhile I've replaced the OneChip/MM3 modchip combo with a PSNee v8, which can do the BIOS patching without forcing the console to boot with 60Hz video.

It's a bit messy to fit the big Arduino Nano into the PS One (already removed the USB connector and button), but it works.

With the PSNee v8 every disc boots at the first attempt now, no more reboots required to get a disc recognized

SylverReZ · 2024-11-14T19:03:20+0000

Fien said:
This PS One still works

Meanwhile I've replaced the OneChip/MM3 modchip combo with a PSNee v8, which can do the BIOS patching without forcing the console to boot with 60Hz video.

It's a bit messy to fit the big Arduino Nano into the PS One (already removed the USB connector and button), but it works.

With the PSNee v8 every disc boots at the first attempt now, no more reboots required to get a disc recognized

PSNee or Mayumi is much preferred, but I'm glad you've got it working now.

PS1/2 Repairing and modchip a PS One?

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