Is this an ATX style PC (where you can command the thing to shut down by issuing a command to do so at the console) or an older AT style machine (where you always have to physically shut it down by pressing a power switch)?

ATX style systems always have power to the mainboard, shut down or not. If you reseat cards on such a machine without first disconnecting the system from the power source (i.e. pull the bloody plug out!) then you risk electrical damage to components. Perhaps this might have happened?

Minimum requirements should be the processor, RAM and display circuitry. To troubleshoot disconnect or remove everything but the processor, RAM, display card. Hook it up to a keyboard and a monitor, and you should be able to boot and have POST screen information displayed.

Thanks for the reply,

No, I don't think its an ATX style machine. It appears to be completely down when the pwr is off and there is no other way to power it off, not from the keyboard.

This is a tool specific computer with some proprietary (I think) video card. I would have to install a "normal" video card to get a display if one were even available. I might give that a shot in the next few days if I don't get the ok from my boss to do the video upgrade thru the tool manufacturer. It costs $10K. Uses a flat panel plasma display that's popular on industrial tools I guess. Nothin's cheap in the semiconductor manufacturing equipment business.

Thanks for the help !

If it's ATX you can track the wires from the power button to the motherboard, if AT the wires will go straight to the power supply. Do as Catweazle said and also check to see if you loosened the IDE connector for the hard drive when reseating the cards.

Hard drive cable is in, pwr is connected, same with floppy...

This thing won't even boot from the floppy, doesn't even turn on the floppy drive light, no spin up.

I've tried two other cpu cards, got the same symptoms. Unknown if they were good or bad though.

thanks

Hi,
I have worked on a few CNC boxes...
You have an AT format box...

If you dont get any spin up of the floppy or hard drives my guess is a bad power cable or power supply or switch on the back of the power supply.

The manufacturing area can get really dusty dirty and cause problems...
I have some service contracts where I clean systems every three months and replace cpu fans and power supplies every six months...
Most of my customers have had ZERO lost time in 10 or more years

Use a meter to test for 115vac at the cord as it plugs into the back

Use a meter to check for 5vdc and 12vdc on the power going to the floppy and other drives. Recheck with the power connection to the motherboard disconnected see if the floppy and other drives spin up.

If you are going crazy and want to keep going I would unplug the hard drive... Unplug all other cards, Install a basic ISA video card and try to boot to a floppy... Some systems have PCI and you can use PCI video if it has a slot or you happen to have a PCI video card.

I strongly suggest isloating the hard drive during this process to protect it.
(Protect it like it was your first born, it can be a real pain to restore it)

You can reach me here or email me at pauldee0046@yahoo.com

Thanks for that Thong_Inspector. I suspected something of the sort but was unsure of the equipment involved.

We usually don't encourage people to post their email addresses in questions or answers, as it directs further discussion away from the discussion topic, but I'm certainly happy to see yours posted there in case lone73 or others reading have such specialised problems to resolve!

One note I'd like to add is that people may be reading this from other parts of the globe. Not every country uses 110 or 115 v AC power supply, so be sure to substitute the correct figure for your location if you are reading this from elsewhere.

Here in Australia, for example, we use 240 v AC for most purposes

I understand that we want to hold these conversations on the public forum. I too learn as I read through the situations brought here.

Even if we do discuss the problem in private emails I will be sure to post the final resolution here. He seems to be in a situation that I can be symphathetic with... I can just see his boss watching over his shoulder...

Thanks also for the reminder that this is a global forum and 115vac is not the standard everywhere...

I do hope we can help this guy get back up and running...

Paul...

FYI
My avatar is my loving dog that I had to put down about two weeks ago.
He was 15 and had many health issues that the vet could not help correct.
You have never seen a bigger flirt running up and down the beach...
We nicknamed him... The Thong Inspector... Truely part of the family...

Thanks for the help! I have 110v to it. Power to the backplane (motherboard?) is there. There is an 8 pin (about) connector with labeled voltages beside every pin going to the backplane board. They are all there and correct. I checked power and ground to the floppy and pwr to the HDD. Reseated all the connectors to the floppy and HDD. No good.

This part of the prob started when I reseated all the cards plugging into the backplane board. I'm thinking at this point that I might have flexed that backplane enough (during the reseat process) to break a trace on the board or open up a soldered pin somewhere.

I dunno, I'm very familiar with repairing other areas of the machine but the computer area probs get me down. If I ever get it going I'll definitely post what the solution was for anyone interested...

thanks.

My question is this...
When you turn on the power do you get a floppy init light and a hard drive spin-up.. They have their own power up self test... Pull the ribbon cables and power it up... You should hear the floppy spin up and the light flash, you should hear the hard drive spin up as well. If not, replace the power supply... You may get getting static voltage but under load it drops below the needed voltage and the zenner dioade is locking it down to prevent damage to the board.

If you have a ribbon cable on backwards it will could be causing this problem but I think you had already checked that...

I would also pull all the cards again, blow out the bus on the motherboard and inspect it carefully for a twisted contact... Clean the edge connectors of the cards before installing.

Is there a small speaker attached to the motherboard...
If not is there a grouping of pins for a four inline connector with a missing key one in from the end where you could put one.

There is a self diagnostic that will give you a series of beeps that might help.

The cpu may or may not have a ZIF arm but if it does reseat the cpu.
Flexing the board may have dislodged the bios chips as well so give them a wiggle.

Somewhere I have a set of bios replacements that you drop in and they will diagnose the motherboard chip by chip... I have had to use them a time or two. I will look for them this afternoon...