Issues with pu-8 modchip .. spindle auto spins

[darph]

Hi,

I recently bought a PS1 scph-1001 with PU-8 motherboard V 1-658-467-22. I just installed a modchip, and the spindle automatically spins at poweron even if the tray isn't down. I went and re flowed the joints and everything seems to be connected just fine. Yet, it still spins, it'll read a game.

I followed this diagram

Any idea what I did wrong? I can't find something that matches that exact model but the points and everything seems to match up with the photo.

[likeabaus]

Not sure if this line is a typo or not "Yet, it still spins, it'll read a game." but is it actually reading any games? Originals, imports or backups/homebrew?

[darph]

Not sure if this line is a typo or not "Yet, it still spins, it'll read a game." but is it actually reading any games? Originals, imports or backups/homebrew?

It reads backups/originals, but it spins continuously unless I unsolder the 8th wire then it stops. Any idea? I thought perhaps I got the wrong schematics

[likeabaus]

Hmm that's odd, what stealth chip are you using exactly?

[darph]

I am using this one: https://www.ebay.com/itm/MM3-MultiMode- ... 3185272622 .. I used this chip on an another same model playstation, but I decided to put it on this one so I know it works and there were no issues on it.

[TriMesh]

It is the wrong install diagram - that's for the "Stealth 2.x" series of chips. On the PU-8, the MM3 does not support full stealth and is normally installed in 4-wire mode with only pins 1, 5, 6 and 8 connected - all of which go to the same places as the corresponding pin numbers on the stealth 2.x series chips (which explains why it's working).

So try disconnecting pins 2, 4 and 7 and see if it works then - note that you won't get stealth mode on that board using that chip.

Definitely you should disconnect pin 2 - that's an input on the Stealth 2.x chips (used to detect pad activity and shut the chip down), but it's an output (for an optional LED activity indicator) on the MM3 - so that wiring is shorting two outputs that might be trying to pull in opposite directions together, which is bad.

The other pins (7 = Door switch, 4 = reset) shouldn't cause any problems, but serve no useful function in non-stealth mode.