AT&T UNIX PC won't boot

Hello, I am new to the UNIX community, however I have a beginner's level understanding of a majority of the basic commands in UNIX.

Today, my teacher gave me her old AT&T UNIX PC. I brought it home, turned it on, and got a completely green screen. I turned it off, and back on and it booted fine. At the login, I typed root and for the password, she had it as eos I believe. (I changed it.) Anyway, I then proceeded to type 'finger' and it displayed the result of only root and powered down. Since then, flipping the switch, I have not been able to turn it back on.

Please help.

What model is it?

Most systems either display something on the screen, or give BIOS beeps to indicate the error condition. The pattern of short and long beeps is the "error code." These are standard by vendor, and can easily be googled.

Is it doing one of the above?

So does anything happen when you flip the switch? Do you hear a fan? Have you looked under the cover to see if there are any indicator lights ON at the motherboard, or elsewhere?

It says no model. On the left side, it says 'AT&T' and on the right it says 'UNIX PC'

No fan. No display.

I did find out that a fuse blew. I tried replacing it and it blew again. Is there a way to find out why this is happening or how to fix it?

Thank you.

Is the fuse in the PC, or in the building? If it's in the PC, then the power supply for the PC may be bad. If it's for the building, it could just be an overloaded electrical circuit.

Capacitors may have dried out and failed in electronics that old. I once had an IBM PC-XT spit flaming bits off the board from a spectacular power supply failure after a decade or so sitting around mothballed...

Could be capacitors. Fuse in the PC. Tried other power supplies. Blew three fuses. I want to fix it though. No matter how much it costs. I know how to solder too.

Other power supplies in the PC blow the fuse? Maybe something on the mobo is already fried.

There could be capacitors on the motherboard too. There must be lots in there. Isn't the monitor integrated? Be careful what you touch.

yes, the monitor is integrated. Oh! You mean power supply, I was thinking power cable. I'll try another power supply.

I sincerely doubt it takes a stock PC power supply, even for the era it was made in.

Does the fan come on at all? Or does the fuse blow immediately when you plug it in?