OK, I F***ED UP, plugged a (floppy drive) power cord directly into MB

[amcfreek]

for testing purposes only
place the item o be tested out on the curb someone will comeby and test it for you
if it test s bad too bad for them
if not they still fix the problem for you
you wont have to test it again

[Dr Jam]

I agree with the last few posts - If you have already tested the parts on a working system.

Check the PSU all the plugs including the MB pwr connectors see how much juice is comming through.

If I remeber correctly the FDD power cables only put out 3v
It may depend on the mb power jumper you plugged the FDD power it into - this might give an idea of how much damage is done

[airems]

WELL HERE'S THE LATEST. LUCKED OUT, GOT A NEW CASE WITH PSU (AT) AT RADIOSHACK.COM FOR $24.95, PUT THAT PSU INTO MY UNIT, ONLY PLUGGED IN THE POWER, HD, RAM AND STILL THE SAME THING, HD SPINS, LIGHT WORK, RESET BUTTON WORKS BUT NOTHING ELSE!! I'VE TRIED DIFFERENT HD, RAM, VIDEO, IT'S A NEW MB AND NOW A NEW PSU. THIS IS THE SAME BEHAVIOR IT HAD JUST AFTER THE FU. AS MENTIONED BEFORE, I EVEN TRIED AN DIFFERENT CPU (EVEN READ THE MB BOOK AND ADJUST THE JUMPERS!) SO I'M THINKING THAT IT'S GOING TO THE LAND FILL AND A POS E-MACHINE WILL FILL IT'S SPOT. WHAT THE HECK THEY ONLY LAST 2 YEARS ANYWAY AND IT WILL BE OUTDATED THEN ANYWAY. PS. Yes I know I'm yelling, but I'm that frustrated.

Thanks for your comments.

Jeff

[Outcoded]

Board and PSU die, dead PSU kills good board...

BUMMER

[burrguy]

See if the power supply works if it does then test the vid card.

[gutted]

So what you're saying is that you've now tried a new mobo against a new PSU with a different CPU, different memory, disconnected the drives, disconnected the kb and mouse, and STILL nothing???

Dude - it sounds like your new mobo is dodgy. It was probably dodgy to start with.

Same symptoms can be caused by a few things - either kb and mouse are mixed up (as previous thread), or CPU and or memory is badly seated, or CPU is dodgy, or reset and pwr connection leads are mixed up. Or mobo is dead. Could be other things, but if you've tried everything in the thread so far you've got to consider that the mobo is dead. Dude - you've tried everything else!! If you bought it new, take it back and exchange it, maybe? And if they ask just tell them it never worked from day one (which is true) and don't tell them that it may have been killed by a dodgy PSU...

It's GOTTA be a dodgy mobo.

[rebelj]

I have to agree with Outcoded - you might have the 12 volts to spin up the drives but not the 5v to power the processor - it is really easy to blow a 5v regulator if you cross-circuit it!

[Terrence]

just a thought; when you hooked up power supply to motherboard......or more to the point of what the power supply cables look like, some of the older power supplies use 2 separate connectors to go to the motherboard, and sometimes get crossed, if this is the case switch them around, also make sure that you have the hard drive and all other devices hooked up correctly. having them hooked up backwards can have this effect.

[LaSERCHiPs]

If I were you I would try building the computer outside the case...easier to swap components...just build it up use the basics
a working video card, a working processor, a functioning piece of RAM, and of working mobo...get this going then start swaping components to see what's good and what's bad

Good LUCK

[leptoid]

Here's how you test it easily. Since all you actually need to get a post is a video card, motherboard, processor, and ram, just those... nothing else. It sounds like you just have a cable backwards... that or you have another bad motherboard. Those things come bad more often than they come good. The past 3 out of 4 I bought were bad so don't rule that one out.

[Outcoded]

Ok, I don't often admit to this, but my other degree is in electrical/electronics engineering, not that I ever finished it (don't tell anyone, or I'll end up mending everyone's microwave).

I am also pretty good at fixing PSU's (no one at work knows how I do this).

1. The connectors should be plugged in so that the (rips lid off 486) black leads are together, otherwise you'll either get smoke and flames or nothing, normally nothing.

2. Get the PSU on the bench, just the PSU, don't connect the board, drives or anything else. Grab/steal/buy/borrow a multimeter, plug the red lead in the V socket, the black in the comm socket and turn it to DCV and a number above 12 (normally 20).

Turn the PSU on (wall and panel switch).

Stick the black in a black wire (a known good drive pug is often the best way) and go around all of the wires (except the black)

Red leads should read about 5
Blue -5
Yellow 12
Brown -12

Post back with the results (don't email me).

[GC74]

That was a great move pal! But don't worry, we all do sensless things once in a while

[burrguy]

Barrow a friends power supply and try it then. If you shorted out the floppy power cable then Its probably the supply.

[knightdemon]

Seems to me that the PSU is half dead. Probably reads good voltages when not under load but when under load doesn't provide enough power to run the system. Try a new PS and see what happens. I blew a PS by shorting the power cable for a floppy to the case when i first went to ATX machines.

[airems]

Latest update! NEW PSU, 2nd New MB, still nothing. Have found a used processor to try. Still the HD spins, but nothing else. No beeps, no floppy. Only have the RAM, Video card, PSU and HD plugged into the MB. Have evaluated the MB instructions over and over again. Will let you know what happens when the new processor comes in. FYI this is now "just a project", I'm determined to figure this out. Thanks again for your valuable help.

Jeff