Fried PS/2 Kybd Port -- Halt on Kybd Set in Bios

**houseisland** · May 2nd, 2003, 11:29 AM

Hi,

I have a Gigabyte mb with a fried PS/2 Kybd port.

I am wondering if it is possible to use the board with a USB kybd.

The system will not POST completely because it is set to halt on keyboard error. The halt on kybd error cannot be turned off because there is no PS/2 kybd to access the CMOS settings.

Any ideas?

**NooNoo** · May 2nd, 2003, 11:32 AM

Catch 22 - gotta love it

However, if you are very very lucky, resetting the bios will reset to halt on no errors... but that is so unlikely

The usb keyboard option could work if there is a jumper to enable usb keyboard on the motherboard - also a rarity

Finally get a ps2 pci card and use that to change the bios... but what happens when the bios resets again....

**PeLiGrOsO** · May 2nd, 2003, 12:39 PM

like NooNoo says.. you might get lucky by clearing CMOS and putting a USB keyboard..
anyways.. how did the ps/2 port fried ?

**Ya_know** · May 2nd, 2003, 12:48 PM

I did this once at home, took a machine down for 3 days, when I got back to it I come to find out that I connected the wrong PS2 ports for the keys and mouse. Good thing I didn't order the mobo...I really felt stupid...

**PeLiGrOsO** · May 2nd, 2003, 01:19 PM

Originally posted by Ya_know
I did this once at home, took a machine down for 3 days, when I got back to it I come to find out that I connected the wrong PS2 ports for the keys and mouse. Good thing I didn't order the mobo...I really felt stupid...

it happens to the best of us..

**houseisland** · May 2nd, 2003, 09:54 PM

PeLiGrOsO,

The PS/2 port was damaged by a user who was attempting to "hot swap" scan wand decoder wedges and keyboards around in an effort to get the scan wand to work. Luckly the decoder wedge was not damaged. The problem is between the keyboard and the back of the chair.

NooNoo,

I have tried resetting the CMOS already, both with the jumper and with pulling the CMOS battery for a few days, but the default setting is halt on keyboard error. There is no jumper for USB keyboard.

I have never seen a PCI PS/2 port card. Where would I find such an oddity?

The other thing I have considered is turning off the halt on keyboard error on another of the same motherboards and then trying a bios chip switch. Any thoughts on this idea?

**NooNoo** · May 3rd, 2003, 04:53 AM

Originally posted by houseisland

I have never seen a PCI PS/2 port card. Where would I find such an oddity?

The other thing I have considered is turning off the halt on keyboard error on another of the same motherboards and then trying a bios chip switch. Any thoughts on this idea?

I thought of that - but when you change the chips I thought the settings would go to default since you have removed the power to the chip....

That's a question for Ruslan and Garak....

As for a separate controller - you can get ps2 cards - but on further investigation they are for mice only

**Atodini** · May 3rd, 2003, 11:43 AM

Sorry houseisland but I don't think there is an easy way to get out of this one. NooNoo is right about thie bios chip, the default bios setting is kept in ROM but any user settings are recorded & stored on the EEPROM, which will lose all settings when the power is disconnected!

The USB keyboard idea almost certainly wont work either as the USB default setting in all bios's I have checked is always off for all legacy devices & keyboards.

Likewise PS/2 cards & mouse adapters don't use all the pins so wont work with keyboards.

Is it possible to get the board repaired? Any competent electronics tech should be able to diagnose & replace the fried bits.

**confus-ed** · May 3rd, 2003, 12:09 PM

You might be able to hot swap the chip, and retain the settings, you'll have to complete the write in the 'damaged' eeprom first then move it .... EEPROM is electrically erasable programmable read only memory ... it won't magically clear itself, it should hold its settings for a while (that's what the cmos battery is for to provide trickle charge & keep the contents there), else the whole hot swap 'cheat' would never work as you have to pull the chip at some point....

As to ps2 'flavoured' PCI cards ... I've seen them too but they'll cost more than a board repair, infact unless you have a mate like our resident electronics whizz Ruslan, then odds are a repair might be as much as a board .... plus once you've 'cooked' a board you can never really trust it again ...

Methinks somebody is gonna have to buy a new motherboard...

**kato2274** · May 3rd, 2003, 12:20 PM

Originally posted by PeLiGrOsO
it happens to the best of us..

or in ya_knows case . . . . the worst of us

**Rkring1** · May 3rd, 2003, 08:15 PM

Ruslan recently helped me thru one like this , it is likely a blown fuse on the board. Should be located near the PS2 ports and labeled FS1 or FS2.Check the continuity w/ your multimeter and replace the open one , or jumper it with a wire (obviously the wire is dangerous...no protection next time ! )

**Ruslan** · May 3rd, 2003, 08:38 PM

>I would check first keyboard fuses, located near keyboard >connector. If someone pulled out keyboard from working >computer (or even worse, connected it back), one of these >fuses most likely is blown (usually that one what is >responsible for +5V, coming to keyboard). So, if you're lucky >enough, you can just replace that fuse (marked on PCB as >F*). Or even just short it with piece of thin wire (bit >risky,though)...
>If it is not a bad fuse, it could be bad I/O controller chip
>(Winbond, ITE or SMC - depends on MB). Then it is real
> problem...

>Good luck!

Looks like I'm late with my reply - Rkring1 already explained everything... never mind... ;

Good luck!

**FatalException0E** · May 3rd, 2003, 11:36 PM

I have this problem pretty often with fuses for cash drawer ports on POS workstations. The hardest part is finding which tiny component it is. Replacement is pretty easy. On my POS stations, I usually go to an electronics store and get some fusible links (a plastic barel fuse holder with wire coming out each end) then sauter the ends of wire to the board where the fuse connected. That way, the next time the fuse blows, it'll be an easy replacement.

**Platypus** · May 4th, 2003, 05:49 AM

housisland, getting the fuse fixed up is your best bet, unless your board is old enough to have a plug-in Real Time Clock chip. The BIOS settings data is not contained in the BIOS EEPROM, so don't worry about swapping BIOS chips. The settings are in a small area (typically 128 bytes) of CMOS ram in the RTC chip. If the motherboard is old enough to have a removable RTC, such as the black block types made by Dallas, Houston, Odin etc, this could be removed, fitted to another board which uses the same type of chip, and the setting changed. This type has the backup battery in the chip, so will hold the settings while it is transferred. Otherwise go with the fuse replacement.

Ok, just re-read the thread and the board has a CMOS battery, so it's not a Dallas type RTC. Same comments apply if the RTC was pluggable, but the settings would be lost almost immediately. Almost is the operative word, CMOS only needs micro-amps to function, and will run briefly from capacitance, but since it's doubtful the RTC would be pluggable, and doubtful it could be transferred quickly enough, fixing the fuse is still the go.

**houseisland** · May 5th, 2003, 09:23 PM

Thanks, all.

It looks like the second fuse on the board is toast. I haven't had time to test it, yet, but there is a sizable pit in solder near the trace at one end of it. I am guessing that it won't pass a continuity test.

If I choose to replace it, what amperage am I looking for?

Thanks again.

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