Modern G4 Cube PSU replacement?

[SteveHere]

Did you just cut the old PSU cable and wire it in?

Yes.

 

[KMM]

Thanks for all useful information.

 

[KMM]

All Guru,
I just have a question. I found a modern one, 24V 3A. I tested with multimeter found out that the polarity of all prongs are in the opposite with apple power mac g4 cube adapter as shown in figure. I put it in cube and it fit perfectly (without electrical).
My questions are as follows;

1. I can't use that adapter with cube unless I find the way to change its polarity to match exactly with cube's polarity or it will destroy my cube. Am I correct?
2. Suppose I can switch all polarity matching cube's original adapter, is it safe to use new adapter with cube? I noticed that even voltage is pretty close to 28V but it has only 3A while cube's adapter said 7.3A.

Thank you in advance.

 

[Byrd]

Welcome KMM, it’s not enough to power the Cube even when you switch polarity of the pins. A Cube with an SSD and not using ADC would not draw as many amps but far from half. I’d keep the connector and find a bench mounted PSU as referenced prior to power you Cube.

 

[KMM]

Welcome KMM, it’s not enough to power the Cube even when you switch polarity of the pins. A Cube with an SSD and not using ADC would not draw as many amps but far from half. I’d keep the connector and find a bench mounted PSU as referenced prior to power you Cube.

Byrd,
Thank you very much for your kind.
I'm confusing since you said that my adapter (28V, 3A) would not enough to power the Cube. I won't use ADC monitor.
On the first page, Stormy had confirmed that 80Watt TDK PSU which has 28VDC, 2.86A, 80Watt, similar to mine, worked. Please explain more to me. I really appreciate all helps.

Thanks.

 

[sgerstacker]

I ordered this power supply...

I can confirm that it works.

The look isn't great, but I normally kept the brick on the floor anyway so I'd rather have the peace of mind than a pretty power supply...
View attachment 80354


EDIT: I should add that the color code for the cable coming from the old PSU to the G4 is:
+24V = Red
+24V = Orange
GND = Brown
GND = Black

Can you show us the actual wiring you did here. I have a G4 power supply wire, which only has 3 cables: Red, Black, &White.

 

[sgerstacker]

Can you show us the actual wiring you did here. I have a G4 power supply wire, which only has 3 cables: Red, Black, &White.

Never mind. I just pulled things apart and realized that the 2 pairs of V wires are combined inside.

 

[SteveHere]

Sorry I missed the post with your question. I don't remember the color code, but using the color code on the cable may not be the safest way to wire this up anyway. Best thing to do would be to use a multimeter to verify the continuity (ohms mode) shown in KMMs post above, then check the voltages after the wiring is complete before plugging it back into the Mac.

 

[Aeroform]

Just wanted to share what I did, found a 24v 150w led driver on Amazon for about $12. The fit was juuust right, making it somewhat easy to fit it in the original casing. Speaking of which, i simply pulled the sides off using only my fingers, pulling on one side until the clip on that side snapped. Put it back together using strong double sided tape. I’m happy with how it came out and took probably 20mins all in all.

This is the power supply I used: https://a.co/d/02dAtsZ9