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dtucker

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getting a 486 motherboard up and running

This has me racking my brains out. I recently purchased a new 486 motherboard because my old one died.
I transfered everything over and when I started it up I got a hdc failure, so I replaced the disk controller card, but I still got a hdc error and I could not get into the bios setup to change anything, so I brought the motherboard back to the store and they said it was running perfectly. I asked them to set the bios to boot from floppy because the hard drive is not bootable. I took the motherboard home and set everything back up again and still I get hdc error hit F1 to resume, but hitting F1 does nothing. I tried to clear the bios to return to it's default state, but now I get CMOS checksum error and a video error, I am at my wits end on what to do, I really don't want to drag it back to the store.
I'd rather fix it myself.
my motherboard is a vl-bus 486 with a 66 DX2 chip, it's an AMI bois dated 1995. I saw it working at the store but that was without my video card or hdc card.
Please point me in the right direction
Dave
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datn

Are you sure you put everything back together correctly, such hard drive cables, etc.? The hard drive cables have pins on them that have to be attached correctly - red stripe on hard drive cable goes to pin 1 of hard drive. Also, your battery might be basically dead. Replave it and try again.
When you hit F1 and you say you get nothing, do you mean nothing shows on the monitor any longer? Are there any noises, etc. to indicate that your system is turning on to any point?
dtucker,
Have you installed RAM since you had it at the store, or is it the same chip(s)? Does it count memory at startup?
I think you need to press delete to enter BIOS setup after the checksum error.(Not F1 to continue)
Save your selections when exiting CMOS setup.(Usually F10 then y)
If still no progress:
1) Unplug the HDD cable from the controller.
2) While in BIOS setup, set drive C: to "none", set appropriate floppy drive and video mode, save, and reboot.
3) See if it will boot from sytem floppy now.
Let us know....
Ralph

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ASKER

Everything is correctly installed,  the battery shows 2 volts when it should be 3 but the motherboard worked fine at the store.
I do get the memory count, then I get the errors:
CMOS checksum error and CMOS display type mismatch.
even without having the harddrive cables installed, only using the floppy cable, I still cannot get into the bios to change anything.
I am ablr to clear the CMOS by switching a jumper, but I still cannot get back to default CMOS setup.
I still need help!!!
If you clear CMOS with the shorting jumper, it has to then detect the installed RAM, hence the checksum error on the first boot.
Sounds like possible power supply problem.
Disconnect ALL leads from power supply except for the motherboard.(HDD,FDD,CD,CPU fan, etc.)
Remove all cards except video adapter.(Modem, I/O card, etc.)
Plug in keyboard only, no mouse or printer.
What happens on power up?
Ralph

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JBURGHARDT

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When your computer boot hold del key this will let you enter bios setings.
JBURGHARDT,
Do you  E V E R  read the prior posts before pushing that answer button?
Ralph

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The hard drive will spin up with no problem, before I got the checksum errors, drive A would be polled but the light would not go off and if I put a bootable floppy in it, it would not try to read it, the light would stay on and the drive would spin.
The powersupply is brand new as is the case, the only cards in it now are the video card which works because the video bios comes up fine. The only other card is the Disk controller card. Now with the harddrive unconnected, because it is not bootable anyway, I just want to be able to boot with a floppy disk so I can get some files off the harddrive that I need before reformatting.
But I still cannot get into the BIOS to change anything.
Hitting the delete key at bootup during the memory test does nothing.
The keyboard is brand new, and I tested it with my other computer and it works fine.
If I disconnect the keyboard, I will get the keyboard error.
How can I get this bios to go to it's defaults, when changing the jumper to clear it did nothing but gve me these errors?
Go back to my first question:  
Have you installed RAM since you had it at the store, or is it the same chip(s)?
Ralph
 
Can you get into CMOS yet?????

If not to get into CMOS just hold down anykey whilst booting. You will then get a 302 error and can enter CMOS.

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ASKER

I have not added any memory.
Holding down any key just gives me a keyboard error.
While the memory is being counted, usually hitting ESC will stop the count but mine dosn't. Also hitting CTRL-ALT-DEL does nothing, I have to hit reset to try rebooting.

Avatar of mikecr
The light on your floppy drive stays on because your cable is plugged in backwards either on the controller card or the back of the floppy drive. Once you change the cable your computer should be able to recognize the change and you should be able to get into CMOS. If not, your hard drive cable my be on backwards also.
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ASKER

Because of a notch in the floppy connector there is only one way to put it on.
The red stripe is lined up with pin 1 on every connection.
dtucker,
Okay, lets get this thing to at least the CMOS setup. (if it's going to!)
I'm still not clear on the RAM.  I ask if it has been removed and re-installed since the board last booted.  It is important to determine if there might be a misalignment of the SIMMs in their sockets.
The memory, if 30-pin SIMM must be installed in pairs on the DX board, so using the process of elimination, try only one pair at a time.  (One 72-pin SIMM should work okay)
You mentioned this to be a VL board.  Are you using a Vesa local bus video adapter?  If so, try installing it into another VLB slot as there may be a problem with its connection or setup.  Bus speed may be a factor here.
If you have a vanilla ISA VGA adapter, by all means, try it.
Forget about copying files or anything else with this guy until you get it set up!
Do this with NOTHING else connected to that motherboard or power supply except Keyboard and monitor.
Let's see, if we see, CMOS.....   :)
Ralph

Gives you a keyboard error but no BIOS option!? Is there a jumper on the MBRD that stops BIOS from being entered?

SO if you just plug in the minumum ie keynboard and monitor (no fdd no hdd etc) itjust gives you a list of errors but no BIOS entry key!?
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ASKER

With only the keyboard and video card attached to the motherboard, I still get
CMOS checksum error and CMOS display type mismatch
press F1 to resume, but hitting F1 does nothing.

When it says press F1 to resume, it then tries to boot.... which ain't gonna happen right now.
Does it also say "Press Delete to enter CMOS setup", or something to that effect???
Ralph

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ASKER

My VL-BUS video card would only work in the bottom slot, the other two slots gave me no video at all. The board has 16 megs on it 4X4 30 pin simms, that is what was on it when it was running at the store. The only thing I did was add a 16 meg. 72 pin simm to the mix when I returned home but it counted up to 32 megs without a hitch. I have since taken that simm back out so I only have to wait half as long till I get the errors.
The memory counts up without any problems.
I have a plain ISA vga card that I tried but I got no video out of it at all no matter what slot I put it in so that card is probably trash.

Wow....  We keep running into dead ends.
With power off, and the ISA video card installed in an ISA slot, not one of the VLB slots, I'd try shorting the jumper to clear CMOS.
Re-boot with it in place, until memory counts, and power off.
Remove shorting cap and re-boot.
What happens?
Ralph

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I did as you said but still no video and by the error beeps I'd say that I still get the same errors.
I get video with the VL-bus card so I'll stick with that.
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Yes in the beginning it says press DEL to enter setup, but pressing DEL does nothing.
I think you have no choice....
Replace the video card. (Perhaps you can borrow one?)
Ralph

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ASKER

Replace my VL card even though I am getting video?
I think it's causing the hang.
It wouldn't surprise me if this caused the problem with the original motherboard that you replaced.  How did it fail?
Maybe changing video card on that one will revive it???
The VLB slots on the new one apparently are not working properly, and the VLB card won't fit anywhere else, so you're left with changing vga adaptor.
I'd get rid of the thing anyway, you'll never be able to use it when you upgrade later....
About the new M/B, can you return or exchange it?  
Ralph

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I think I will go back to the store with my video card and HDC card and see if they can get it running.