deskthority

Hey guys,

so I just disassembled, cleaned and reassembled my first IBM Model M. It was pretty dirty so I cleaned the case with soap water and the PCB with distilled water, alcohol and a Q-tip (only the parts under the keys). Some days later I reassembled it and tried the keyboard.
First I hooked up an USB/PS2 adapter I found (active I think) http://www.amazon.de/2-Adapter-f%C3%BCr ... pter+aktiv
When booting the 3 status lights flash for a second and after booting the Num light is on.
But the keys don't work. None of them. USB 2.0/3.0 - not working.
I also tried the native PS2 port on my mainboard (mouse/kb multi port, Asus Rampage V Extreme). Again, not working.
Only the Num light. I always rebooted between switching the cables/ports.
Is my Model M defect? Maybe there's still a little bit of distilled water in the keyboard/switches?
Unfortunately there is no model/serial number on the case, but it's a original IBM with the SDL - PS2 cable.
Is the current too low?

I don't know what to do Please help

It's probably because you're using an adapter instead of an active converter and the computer has no idea what the hell the keyboard is on about. Model Ms don't work on my native PS/2 port either, I need a converter as well to run them. I've asked why this is, and people mentioned that it's probably not actually a native port.

I don't think there's anything actually wrong with the keyboard. Try an active converter instead and see if that helps .

But I think it is an active adapter. It looks exactly like that one from the amazon link.
I also just hacked together an old Windows 98 computer and tried the keyboard there. Again - lights are on, keys don't work.
And this MB has native PS2 ports.

I had that problem once with a keyboard, but just don't remember how I solved it. I recall PMing Soarer in a panic because I was at 43 days after purchase (2 more days to file paypal complaint). If I remember I'll contact you. Somehow between changing adapters, using ps2 port on computer, and restarting, my problem went away.

I just ran into this same problem, myself. I picked up a new (to me, obviously) Model M and verified that it worked on a PC with a PS/2 port. I then did some light cleaning under and between the caps with Q tips and some isopropyl. I had a quick look inside the case and since it was already pretty clean, I didn't poke around, I just put it right back together. Now the Num light illuminates and that's about all it will do.

I'm using an AT type keyboard (Gateway AnyKey) via that same PS/2 port right now, so the PC didn't have a melt down. Hopefully I'll have some time over the weekend to determine what's going on.

Isopropyl alcohol can leave a residue that is conductive. Try rinsing really well with distilled water, or better yet, use denatured alcohol. Keep cleaning with a small sponge type applicator on a stick, like a tiny lolipop, until the sponge comes away clean. I have seen cotton swabs leave all kinds of gunk behind.

I think it's time for a screw mod

The only way to really clean and dry everything properly...

elecplus wrote: Isopropyl alcohol can leave a residue that is conductive.

Wait, can it? What residue is that? Oo iPrOH should evaporate very quickly and cleanly, I'd think =o .

Chyros wrote: Model Ms don't work on my native PS/2 port either.

Errr it might have something to do with your mainboard then, I've been using all kinds of M's via PS/2 with my ASRock P67 Extreme4 which is older but not antient.

Chyros wrote:

elecplus wrote: Isopropyl alcohol can leave a residue that is conductive.

Wait, can it? What residue is that? Oo iPrOH should evaporate very quickly and cleanly, I'd think =o .

"In most instances, IPA is too aggressive for most plastics and can intrude into parts and spaces creating undesirable effects. IPA is known to dissolve polystyrene and other types of plastic capacitors. By dissolving various materials, a potential low-ohm and conductive film is spread over the surface of the PCB" from http://www.aclstaticide.com/blog/flux-c ... hs-basics/
We were always taught in electronics repair classes to never use IPA, only denatured alcohol. IPA sold at the drug store can contain small amounts of things like lanolin, which is wool fat.

elecplus wrote:

Chyros wrote:

elecplus wrote: Isopropyl alcohol can leave a residue that is conductive.

Wait, can it? What residue is that? Oo iPrOH should evaporate very quickly and cleanly, I'd think =o .

"In most instances, IPA is too aggressive for most plastics and can intrude into parts and spaces creating undesirable effects. IPA is known to dissolve polystyrene and other types of plastic capacitors. By dissolving various materials, a potential low-ohm and conductive film is spread over the surface of the PCB" from http://www.aclstaticide.com/blog/flux-c ... hs-basics/
We were always taught in electronics repair classes to never use IPA, only denatured alcohol. IPA sold at the drug store can contain small amounts of things like lanolin, which is wool fat.

That's really bizarre, because denatured alcohol is a much more aggressive solvent than IPA xD . Electronics-grade alcohol is IPA, too.

Don't take this the wrong way, 'cause I definitely appreciate the feedback, but I've used this same bottle of alcohol on several PCBs now. As a matter of fact, I just finished a Clueboard last week and I used this same bottle of alcohol and a stiff brush to scrub the rosin off of its PCB. I've never had an issue with using this process on that, or any other board that I've built.

Now having said that, alcohol does definitely attack some plastics. I've also seen it cause massive spiderweb cracking. But, on this M, I only used alcohol on a swab on the exterior surfaces, around the keys. The inside of the case was surprisingly clean, so all I did was to lift the sandwich up long enough to count one missing plastic rivet and then I buttoned the case back up. I soaked the keycaps in warm soapy water and I dampened a lint free cloth with warm soapy water and used that on the exterior surfaces of the case. I let everything dry over night, before replacing the keycaps. So, I find the fact that the board now refuses to work, just a wee bit mysterious. Oh well, I'll get back to it in a few days ...