can I USE a 7500 power-supply in my BEIGE G3 DESKTOP

I doubt the pins would match and the Wattage is more in the G3 (230W) versus the 7500 (150W)

This is upsetting, I can only wished you are mistaken.

Beige G3's can use a standard ATX PS if you move the jumper on the MB from apple to ATX. Of course you would need to find one that fits the case.

Are we sure 7500 power supply not a possibility?

The jumper is marked Mac supply and PS/2 supply IIRC. Set it to PS/2 and you are set for use with an ATX PSU.

Drop the 7500 idea, just get an ATX PSU.

The 7500 PS has same dimensions as beige G3 desktop PS. An ATX would not be quite a right shape. I also know an incredible man with a wealth of 7500 service parts which I could help myself to. But would it be compatible? That the mystery.

Please, just stop. Get an ATX PSU, plug it in, and be happy.

Also, unless I am mistaken most older Macs use a different method to trigger a startup than the Beige G3 and later models anyway.

Just stop thinking about the 7500 PSU. If you knew what you need to in order to make a 7500 PSU work then you would not have needed to ask in the first place

Listen to us for maximum happiness and minimum fried hardware.

My problem is that the [EXPENSIVE :disapprove: ] ATX PS is not matched the special shape of the desktop beige G3 PS. The [CHEAP :approve: ] 7500 PS would fit for perfection.

So plug it in and blow it up, problem solved.

Why so tart? I still have not seen ATX PS of correct shape nor any proof that a 7500 PS would actually blow it up.

Actually, $50 buys an ATX PSU that can run a modern almost highend PC and has the advantage of being both new and more compatible and easily swappable into other (modernish) syetems, etc. It is likely to outlive the usefulness(or even functionality) of that Beige G3 anyway.

The 7500 PSU is fifteen yearsold. 8-o It will just be a failure point in the future(and it does not have as high of a capacity as the Beige G3 want, as someone before mentioned)

It is way way more work to wire up a 7500 PSU for a Beige unless you actually know what you are doing and have experience with this sort of thing.

If fit matters that much to you then take a 7500 PSU and an ATX PSU to a electronics repair shop and see if they will put the guts of the ATX PSU in the 7500 case. Then you get a modern PSU that has a perfect fit and no hackjob-wiring. To get it done properly will likely not be super cheap though...

Is it sure that the 7500 PS will not work plug & play? I do not put much stress on PS. I have stock CPU and one PCI card (ORIGINAL RADEON)

Yes.

There are bricks shooting out of my seat! I am furious! In what way is the 7500 PS not to be compatible with the beige G3 desktop? Is it the connector?

It is not compatible in more than one way. It is not worth it. In the time you spent asking us if we are wrong, you could have ordered an ATX PSU online and been done with it.

Bricks out of your seat you say? I would get that looked at by an experienced mason right away.

But in just what ways is the PS incompatible with desktop beige G3? I can wait…there will be enough bricks to build a house of mine.

Obvious troll is obvious.

The pinout and startup trigger are wrong. The 7500 PSU is too old and under the higher load of the newer system would be stressed more than a 7500 would stress it. Extra load for such an old PSU(or any for that matter) = more heat and stress. Stress and heat = failure.

This PSU was designed for a completely different computer.

Go ahead, plug it in.

But there have been pretty mean 7500s out there. I saw 1ghz sonnet G4 for 7500, even SATA cards. Must the PS be powerful to handle that load?

Those people are pushing their ancient PSUs. And not many people really deck out a 7500.

But the fact still remains that it's PSU is not going to plug in and function for you.

I am now upset.

To rectify being upset you can go get a nice new reliable ATX power supply and make your computer work properly and safely.The new PSU(go with Seasonic or Corsair) will also have higher efficiency and it's power output will be more stable than anything that ever came in an old Mac.

*edit, actually, SATA cards are not much a load and any normal SATA HDD is likely to either use the same amount or less power than ancient SCSI drives.

Will it lower my power bill? Would be quieter fan?

Shooting bricks? What do you guys figure, English as a 2nd (maybe 3rd or 4th language) or machine translation?

The 7500 has a different arrangement of signals in the power connector.

The 7500 uses a different power connector -- actually two power connectors, where the ATX in the Beige uses one.

The power connectors have different numbers of pins.

The Beige G3 runs it's power-hungry circuitry on 3.3V where the 7500 uses 5V for those components. Therefore the 7500 has inadequate 3.3V supply for the Beige G3.

In order to turn the power supply 'On' in the 7500 the logic board ties the "Power On" pin to the 5VSB pin. In order to turn the power 'On' in a Beige, the logic board ties the "Power On" pin to Ground.

You may not find a power supply that is the exact shape, but small powerful ATX supplies abound which can be fit into the Beige G3 case. For example this might be close, although the power available is a little low: http://cgi.ebay.com/Gateway-E4000-Small-Form-Factor-P4-Power-Supply-6500696_W0QQitemZ400085097058QQcategoryZ3670QQcmdZViewItemQQ_trksidZp4340.m263QQ_trkparmsZalgo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%252BDDSIC%26otn%3D20%26pmod%3D400102982379%26ps%3D63%26clkid%3D6127263069489856293

And a little shopping on Newegg or at Frys will turn up all kinds of others.

Very thank you!!

Just realized that the "In order to turn the power supply 'On' the logic board ties the 'Power ON' pin to..." bullet in my previous post may be incomplete.

I wrote that the Beige ties the 'Power On' pin to Ground, but it is possible that in the Beige G3 that depends on the setting of that jumper on the logic board. That may be exactly what that jumper controls -- whether 5VSB or GND is used to trigger 'Power On'.

It is true that a 7500 PS expects 5VSB on 'Power On' as an 'ON' signal and an ATX PS expects GND as an 'ON' signal, but it may be that the Beige G3 logic board can supply either 'ON' signal depending on how the jumper is set.

I'm not sure, but I think that is the case.

That might be an interesting thing to explore with a meter on a bench just for the sake of finding out.

Does anyone have a handy AIO Beige G3 PSUs to check this? It was the AIOs that used that setting wasn't it? I seem to recall people writing that they just plugged in their ATX PSUs when they were working with the non-AIO ones.

*Edit

Mac Gurus says "Desktop chassis" so I guess that covers the AIO and desktop model while excluding the minitower based one+it's "server" version.

I have a working beige g3 power supply i pulled years ago. its floating around here somewhere, i could test the theory with that?

Was it minitower or desktop?

Take a look at it even if you cannot remember what it was from.

i stripped a G3 desktop years ago. and kept its power supply. the logic board died, which is why i stripped it.

Epic thread is epic.

I really wish I had more to add, but I don't. I just read the whole thread and kinda sat in my chair, stunned.

Will the circle plug into to the square?

No?

Why?

It's a circle, not a square.

But I have a lot of circles, are you sure it won't fit?

Try it.

Bricks.

Um, yeah.

Some times, when folks are dealing with stuff new to them, they really need a little extra hand holding. This is especially understandable given the ready availability of wrong information and folks (usually not here) who will answer questions glibly and wrongly.

You can hardly blame a fellow for wanting a little extra exposition and reassurance.

A little patience goes a long ways.