However, in the case of passive PSUs without a fan, you have to attach a case fan to the 4-pin Molex connector of the PSU to check that the PSU has started. This still indicates that the PSU is functioning normally.
Note: Some power supplies have a zero-RPM feature that results in the fan only spinning for a moment after the PSU is powered on. If the PSU fan starts spinning then it means the PSU has started and is powered On. Plug the PSU cable into the mains power socket, turn ON the mains power, and also the power supply if the PSU has an ON/OFF switch.Ħ. Insert a paper clip, solid copper wire, or small wire in the 4 th and the 5 th pin you have located.ĥ. Here the fourth pin is the ‘Power On’ the sensor pin and the fifth pin is the ground pin.Ĥ. Now count the fourth and fifth pin from the top-left of the connector. Hold the 24-pin or 20-pin connector in such a way that the connector clip is facing up and the pins toward you.ģ. Unplug the PSU from the computer and mains.Ģ. Steps for Testing PSU without Motherboardġ. In the images below, you can see the green-colored Pins in the 24-pin and 20-pin connectors are ‘Power Supply On’ sensor pins. For the 24-pin connector, it is PIN 16 and for the 20-pin connector, it is PIN 14.
It is done by shortening the Power Supply ON (PS_ON) Signal Pin of the 24-pin or 20-pin ATX connector of the PSU with any one of the ground pins in the connector. It is a basic Power ON test to check whether the PSU is starting or not. Thanks again!Here are the various methods by which you can check or test the Power Supply Unit (PSU) of the PC. Any other advise or sites related to keeping it alive will be appreciated. I'm really hoping I can revive it, but on a fixed income budget. I do graphics (99% with Photoshop CS3) and the only real problem I was having before buying the Mini was that the G4 was too slow online (the Browser I guess), but the G4 served me well for everything else.
The fact is I bought a 2014 Mac Mini (refurbished) but I really like the old Big Mac and software from that era. I'm no electronic technician but pretty handy and follow instructions carefully. I think it was the first model with firewire 800 and last without USB 2.0, which I added about 2003. For a year or 2, I was starting up with the power "button" on the 17" Apple display that I bought at the same time as the Mac G4. I wondered if there is a separate test for the power button board - the power button was acting up long before the complete failure to start-up. I haven't had a chance to test anything yet. So you are not alone in wanting to keep your G4 in service.Īllan, thank you very much! I haven't been checking email lately - sorry I'm so late thanking you. My plan is to scavenge the FPB and power supply from my son's working G4/MDD that he no longer wants or needs.
My multi-boot 1.25ghz SP G4 MDD is not starting properly and I need it for CS2 and a CAD program I must use for a series of technical drawings I started in 1999.
I'm in the same boat but haven't had time to chase down an M2452. Use the board as the start button for the rest of the computer's life. He suggested not trying to replace the board (they were more expensive back then) but simply leave the M2452 attached but tucked out of the way. If the computer starts from the keyboard, the FPB is defective. The button on the board should override the one on the front panel board. My tech said attach the keyboard to the G4 and hit its power button. It has a power button on it like the older Mac boards.
The specific model number is important: M2452. His recommendation was to get one of the first USB Mac keyboards. The only test of the front panel board I've heard was from a savvy Mac tech who seemed to be willing to go "off-book" for simple solutions to tricky problems. Not a problem, Jeff, I'm just glad you found this.