Could this be the processor?

[JohnD]

I recently had a fault on my main PC, and dragged out the standby one, couldn't get a display and decided to bin it.

While I was browsing ebay to see if the remains would fetch anything, I happened to see a m/board of the same range as mine.

I bought it, put it in the case... still no display.

I fitted the known working PSU from my main PC and the known working AGP card (the m/b has on-board graphics as well). Still no display. I checked the case-to-mb connectors and am satisfied they are correct.

When I turn it on now, the PSU fan starts and runs; the CPU fan starts and runs; if there is a hard or CD drive connected, I hear it start up and skitter about. The HD LED lights for a while, then goes out after a minute or so. If I press the "reset" button the PC sounds like it is restarting (lights blink, drive starts up again and skitters). If I press and hold the Power On button it powers itself off.

Looks like it was a mistake to buy a replacemnt m/b. Do these symptoms sound like it is the CPU (Athlon XP 1800, socket 462) or the memory (P133, 2 x 512)?

I could buy a cheap Duron or something but am beginning to regret not binning it earlier.

 

[Softus]

Looks like it was a mistake to buy a replacemnt m/b. Do these symptoms sound like it is the CPU (Athlon XP 1800, socket 462) or the memory (P133, 2 x 512)?

Yes. Or a faulty m/board.

BTW, the skittering noise you hear coming from the hard drive soon after power is applied to it is just the sound of it thermally calibrating itself.

I could buy a cheap Duron or something but am beginning to regret not binning it earlier.

I very rarely buy a m/board without an accompanying CPU, even if second-hand. There's just too much ways in which things can go wrong otherwise.

Did you test the PSU before connecting it?

 

[JohnD]

PSU: I put a multimeter across the two pairs on the IDE power socket, they had correct voltage across each pair (forget the number, was it 5.5v?) but did not try the 20-pin connector as i didn't have a spec of what it should do

I am considering the possibility that the old PSU might have a fault, possibly an overvoltage, which has caused some damage. Sadly I first tried the new board on the old PSU before swapping the known good PSU in.

When I remove the processor, memory and all drives, I still get no display with old or new m/b, although I see from my old notes that I briefly did get a display on the old board after resetting the CMOS.

I think my new PC (Sempron 2800+) also has a socket 762, if so I could perhaps try the old Athlon in here unless a faulty processor could damage the new m/c. However I will not put the Sempron processor on the old board as it is not on the makers compatibility list and I don't want to risk damaging it.

 

[Softus]

PSU: I put a multimeter across the two pairs on the IDE power socket, they had correct voltage across each pair (forget the number, was it 5.5v?) but did not try the 20-pin connector as i didn't have a spec of what it should do

I am considering the possibility that the old PSU might have a fault, possibly an overvoltage, which has caused some damage. Sadly I first tried the new board on the old PSU before swapping the known good PSU in.

If you're going to be doing this kind of thing again, get yourself a cheap PSU tester (such as this one).

When I remove the processor, memory and all drives, I still get no display with old or new m/b, although I see from my old notes that I briefly did get a display on the old board after resetting the CMOS.

I can't think of any way in which a m/board without a CPU and memory could possibly put anything on a display.

I think my new PC (Sempron 2800+) also has a socket 762, if so I could perhaps try the old Athlon in here unless a faulty processor could damage the new m/c. However I will not put the Sempron processor on the old board as it is not on the makers compatibility list and I don't want to risk damaging it.

Very wise. I wouldn't take that risk.

 

[suffolklad]

hi when u changed mb and tried a agp card did you go in bios and change setting for not using the onboard graphics? as if you didnt you wont get alot on the screen . or if its an old mb change jumpers ?

 

[JohnD]

can't change the bios as I can't see it.

No reference to jumpers for display in the m/b booklet.

But I reset the m/b CMOS so would have expected it to set itself to onboard graphics.

 

[tim west]

you did check it wasn't a faulty monitor?

 

[JohnD]

yes, by connecting it to another PC.

it is an old CRT monitor so unlikely to be a compatibility or refresh rate prob.

 

[JohnD]

... Could this be the processor? ...

Yes... it was

I bought a used barebones cheaply, it ran with my old memory, when I swapped my old processor into it... no display

The vendor threw in a spare processor with a couple of bent pins, I might try hammering them back to shape to see if my old m/bs work now.