Power Supply Voltages

[John]

Any opinions on these voltages on my new power supply?

The are from the BIOS. I have had a couple of other PSUs which have had
fairly close readings from this BIOS.

Here's what it reads:

VCore 1.79
3.3v 3.25
5v 4.78
12v 12.48

Are these close enough to run on, or am I looking for trouble. Should I
send it back?

 

[Michael A. Covington]

5v 4.78

12v 12.48

Are these close enough to run on, or am I looking for trouble. Should I
send it back?

The latter two look almost out of specification, but before drawing a
conclusion, read them with a real voltmeter (red-to-black and
yellow-to-black respectively on a disk drive connector while the machine is
running).

As I recall, the tolerance is 5%, meaning 4.75 is the minimum for the 5-volt
supply and 12.60 is the max. for the 12-volt supply.

 

[John]

The latter two look almost out of specification, but before drawing a
conclusion, read them with a real voltmeter (red-to-black and
yellow-to-black respectively on a disk drive connector while the machine is
running).

As I recall, the tolerance is 5%, meaning 4.75 is the minimum for the 5-volt
supply and 12.60 is the max. for the 12-volt supply.

In the 70s we had some disk drives that required lower voltages to have
much tighter tolerances, so I was more concerned with that 3.25 for the
3.3v.

I'll get my voltmeter on the 5 & 12, as you suggested