Bad ps/2 port ?

[MiKl]

Hi guys, earlier today without apparent reason on one of my systems some keys on my wireless keyboard did not worked any longer.

S, V, K and a few more.

So I rebooted but the problem was not fixed. I tried a different keyboard but that did not helped either.

The problem is also present on XP.

 

So, can a ps/2 port really partially break down just like that ? Is there a way/test to make sure it is indeed a hardware failure ?

(I have not resetted the BIOS to defaults yet, I mean, it can't be that easy to fix or can it ?)

Edited August 17, 2015 by MiKl

[Drugwash]

Wireless keyboard? That has nothing to do with the PS/2 keyboard controller unless the receiver connects to the PS/2 port, something I've never heard of yet. So you should look into the (most likely) USB receiver, replace it if possible (at least temporarily).

 

Now, if by chance the receiver does connect to the PS/2 port, first of all try to completely power off the machine and pull the power cord off (or toggle the power switch on the PSU if there is one). Let it rest for a minute or two, then power it back on. In the mean time replace the batteries on the keyboard(s), make sure they are fully charged and contacts are not rusty. If it still exhibits the unwanted behavior, then it is possible that the keyboard controller is bad. You may try a BIOS reset if you like, just make sure you type down all the current settings and after reset you set them back as they were, otherwise resources may be assigned differently and the OS may not like it.

 

If you suspect there may have been a virus, you may also try to reflash the BIOS if you have a 100% guaranteed working BIOS image for that board and all the needed tools. But be extremely careful - I flashed the wrong image on a board (although it was original but for a different RTC on same mobo version) and bricked it. You've been warned!

Edited August 17, 2015 by Drugwash

[netbookdelgob]

This problem is common on netbooks with windows 9x, when windows 95/98/ME hangs, the mouse doesnt work even if you restart the computer, you have to remove the battery and if plugged the power cord.

 

its a wireless usb keyboard right? Did you try a live cd?

[Mathwiz]

Wireless keyboard? That has nothing to do with the PS/2 keyboard controller unless the receiver connects to the PS/2 port, something I've never heard of yet.

I'm not sure about a wireless keyboard, but I do have a wireless mouse (Micro$oft's!) whose receiver hooks to a PS/2 port, so it wouldn't surprise me.

 

Hi guys, earlier today without apparent reason on one of my systems some keys on my wireless keyboard did not worked any longer.

S, V, K and a few more.

So I rebooted but the problem was not fixed. I tried a different keyboard but that did not help either.

The problem is also present on XP.

 

So, can a ps/2 port really partially break down just like that ? Is there a way/test to make sure it is indeed a hardware failure ?

(I have not resetted the BIOS to defaults yet, I mean, it can't be that easy to fix or can it ?)

Was the different keyboard also wireless, or was it an ordinary, wired PS/2 keyboard?

[MiKl]

Thanks for the responses so far !!

My keyboards and mice are all wireless and their receivers are connected with small USB-to-ps/2 adapters. Those adapters were pretty common here in Germany back then in the transition phase from ps/2 to USB so I thought they were widely known. Sorry, should have made that clearer.

 

@ netbookdelgob. I don't have much experiences with notebooks so can you maybe explain a little bit more what may have happened in my PC ?

Win98SE did not hang/crashed. The keys just stopped working while I was writing some text.

The mouse is not affected and works perfectly with the different keyboards/receivers which I tested.

 

@ all. Would love to avoid resetting the BIOS if possible for the reasons Drugwash mentioned above so any other suggestions are very welcome. (I already completely unplugged the power cord after realizing that the problem also exists on XP.)

[rloew]

Have you tried changing the USB to PS/2 Adapter?

[Mathwiz]

OK, I get it. The receiver has a USB plug but that's plugged into a USB-to-PS/2 adapter, and the PS/2 end of the adapter is plugged into your PS/2 port.

 

Seems like you've eliminated the keyboard itself as the problem (you tried another one) as well as the OS (same problem with 98 and XP). That leaves the keyboard receiver, the USB-to-PS/2 adapter, and the motherboard as possibilities (although to me, the motherboard seems unlikely to be the problem).

 

Assuming you have two USB-to-PS/2 adapters, one for the keyboard and one for the mouse, try swapping them. If that's the problem, that will either fix it, or change the symptoms (the mouse may start acting up instead of the keyboard). If that happens, you'll know the problem is one of the USB-to-PS/2 adapters.

 

If not, well, I don't know if you have another keyboard receiver to try....

[MiKl]

Quick update - but I am now even more confused.

After testing several combinations of different keyboards and receivers/adapters I decided to get the whole set (keyboard, mouse and receiver) from the PC in the living room. (Although that meant I had to move some furnitures ....) and indeed this set worked !! So there is fortunately no hardware failure and I don't have to do some desperate measures like resetting the BIOS, etc.

But, of course, I continued the tests in the living room and the problem is also present there BUT with one of the other spare keyboards - one that doesn't actually belong to this receiver - it worked again 

I hope that someone with more hardware knowledge than I have might have an idea about what is going on here ???

[netbookdelgob]

Well its not your case, but on some netbooks and notebooks, usb doesnt work on windows 98 se, if you put a usb it hangs and the ps/2 mouse doesnt work until you remove the battery and power cord. But i repeat this is not your case.

[Drugwash]

You really need to narrow the issue down to either the adapter, the receiver or both.

 

There may be intermitent failure due to overheating, over/under-power, momentary high current drain due to bad reception, bad components and so on.

I know those adapters, incidentally I gave one away to a friend yesterday. I had two of them and they both have a tiny mouse embossed near the PS/2 side, which means there is a possiblity that a keyboard may not (correctly) function with such adapter. Try to look closely at all your adapters, see if they have different signs on them.

 

if you find the right compatible HID drivers you may try to connect the receiver directly to an USB port, if available, see if it works reliably that way.

It's possible that neither the adapter(s) nor the receiver(s) are bad but a momentary overcurrent due to bad reception could trigger a PS/2 port protection of some sort (probably built into BIOS) that would lead to the behavior you described.

Edited August 18, 2015 by Drugwash

[MiKl]

Hi guys, thanks for all the input so far. I spent a few more hours yesterday evening testing the equipment.

 

1) Office/work room. Here occured this problem. Right now I have a 'Logitech cordless keyboard' connected to the PC and it is working perfectly so I think there are no hardware problems in this machine. (I am typing at this PC right now)

 

2) Living room PC. Here I further tested the problematic keyboard 'Logitech cordless desktop Express' - in fact I have two copies of this model !!

- On the one that was in use the same keys still do not work !

- The other one that was not in use and meant as a backup in case of problems does not work at all. Ha, ha, ha ....

 

So I tested these two keyboards again on the PC in the office where the receiver is obviously working but no success.

Maybe there are some issues with the frequency which this keyboard uses ?

 

But I think I need to buy a different keyboard now. Do recent models work with Win98SE ?

Edited August 19, 2015 by MiKl

[Drugwash]

Dunno, never had one and probably wouldn't have it for long because at the first sign of malfunction I'd smash it into pieces.

I'm very happy with my three 20+ years old IBM Model M keyboards, they never miss a keypress and have veeeery long curled cords. B)

[submix8c]

USB->PS2 adapter is simply a "rewire" of the connection. There's also PS2->USB so I doubt this is a problem. Driver is irrelevant in your case. The keyboard (from the tests you've shown) indicate that it's a deader. Time for a replacement.

[Drugwash]

Don't make me use the hammer on the remaining adapter.    PS/2 works through +Vcc, GND, CLK, Data while USB works through +Vcc, GND, Data+, Data-. There has to be an active conversion of the signals, otherwise why bother to designate different sockets for same signals!?

But yes, apparently the keyboard itself in this case is failing or maybe the batteries are bad or contacts are rusty.

[Mathwiz]

My M$ wireless mouse and PS/2 receiver have switches, with the positions labeled "1" and "2." I assume that sets the frequency to use.

 

(Unfortunately I couldn't find the actual RF frequencies it uses documented anywhere! I'm guessing maybe 418 MHz and 433 MHz, since those two frequencies are commonly used for these kinds of devices, at least in the US....)

 

I don't know if wireless keyboards in Germany have a similar switch, but if they do you might give it a try. (Make sure to switch both the keyboard and receiver! If they don't match, it won't work.) All these problems could just be RF interference from something else in or near your living room PC.