SCPH-7501 PU-22 playstation recovery

General information to do with the PlayStation 1 Hardware. Including modchips, pinouts, rare or obscure development equipment, etc.
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Aero_105
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PlayStation Model: SCPH-7501
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SCPH-7501 PU-22 playstation recovery

Post by Aero_105 » September 9th, 2022, 8:45 am

I installed a MM3 modchip and the solder bridged one point and possibly another see reference photo in yellow point 6 for sure and maybe point 1 accidentally. Once powered on a burned game copy would adburtly stop 10 mins and then 40 into game. I then corrected point 1 and 6. Same occurrence but different times in game. I then removed the modchip altogether used an actual game disc and random shut down again but 1 hour into the game. Basically the machine restarts on it's own and I notice the power led actually turns off so it's not a reset button issue. I don't know if the game disc is the issue? What happens if the game discs cannot be read mid game? Is there a certain screen that shows dirty disc error? I do know that once the machine reboots it is more likely to do it again seconds later. What tests can be done to determine the issue? Is it possible a poor connection from the power supply to motherboard? It all happened when I started taking the machine apart maybe trouble happened before. I do know a different game disc the problem didn't occur an 1 hour in game.
referencePU-22.jpg
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nocash
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Post by nocash » September 9th, 2022, 11:44 am

I don't think that the power LED could switch off (unless the power supply is shutting down, switched off, disconnected). I haven't checked how the LED is wired up exactly, but you can check the service manual with schematic here http://www.psxdev.net/downloads.html
If it's a power supply problem, possibly reasons might be: The supply is overheating (because a shortcut in the console or some external controller is drawing too much current), plug, cable or power switch has bad contacts (more likely to happen when you wiggle the cables), or the power supply is damaged or wrong type.

Aero_105
What is PSXDEV?
What is PSXDEV?
Posts: 4
Joined: Sep 09, 2022
PlayStation Model: SCPH-7501
Location: Canada

Post by Aero_105 » September 10th, 2022, 8:30 am

Is it possible a dirty disc could cause a shutdown when the laser can not read mid game? Is there an error screen? I've seen videos where the playstation intro logo with black back ground pauses because it can not read the disc. What happens when the disc can not be read mid game?

Aero_105
What is PSXDEV?
What is PSXDEV?
Posts: 4
Joined: Sep 09, 2022
PlayStation Model: SCPH-7501
Location: Canada

Post by Aero_105 » September 10th, 2022, 11:14 am

Have a look I don't think any solder joints from the mod chip are bridging. Photo number matches number on first post image. One game there is no random power off the other game causes it. Not sure what to make of it.

https://drive.google.com/drive/folders/ ... sp=sharing

Aero_105
What is PSXDEV?
What is PSXDEV?
Posts: 4
Joined: Sep 09, 2022
PlayStation Model: SCPH-7501
Location: Canada

Post by Aero_105 » September 13th, 2022, 7:39 am

I managed to get the playstation running without any power interruptions. I removed the metal shielding, slightly bent the power pins on the motherboard connector for better contact. I think it was the shielding possibly causing grounding at the solder points. So far so good.

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nocash
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Post by nocash » September 13th, 2022, 6:32 pm

solid problem, solid fix... makes me wonder if modern consoles are having helpful error screens for such issues ; )

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