Odd problem with 1391401 and adapters

[itlnstln]

There's a link in the article pointing you to the place to download the software.
If you're not keen on adding it yourself, just send me the data and I'll add it.
 
-huha

No prob.  I just have to find the time at work to do it.  I know it works for every keyboard in my sig (even the USB ones, minus the ABSs, using the PS/2 adapter).  I just need to find an ISO 'board to test with.  They're not easy to find around here.

[IBI]

I've put the Monoproce one through its paces.  It's always a go.

Has anyone else tried it with the SGI AT101? CX reported that it didn't work so it'd be interesting to know whether that's a one-off or not.

[itlnstln]

Da Blue Cube sez:
 
Can't you handle a SGI in da face!

My Monoprice adpater handles my Dells just fine (same 'board).

[IBI]

My Monoprice adpater handles my Dells just fine (same 'board).

I know they've got the same shell but are you sure they've got the same controller as well as that'll affect whether they work with the adapter - and it was designed for SGI systems rather than for PCs generally so it's a good chance it may not do.

[itlnstln]

I know they've got the same shell but are you sure they've got the same controller as well as that'll affect whether they work with the adapter - and it was designed for SGI systems rather than for PCs generally so it's a good chance it may not do.

As far as I know, they share the same internals the only difference being the dampers on the switches.  If someone has both 'boards, preferrably of close vintage to help eliminate time-based hardware revisions, maybe they can look into it (no pun intended).

[skriefal]

I own both keyboards.  Are you asking to test them with the "blue cube" or with the Monoprice adapter?  I do have one of the blue cubes available as well as one or two other PS/2->USB adapters, but none from Monoprice.

[itlnstln]

I own both keyboards. Are you asking to test them with the "blue cube" or with the Monoprice adapter? I do have one of the blue cubes available as well as one or two other PS/2->USB adapters, but none from Monoprice.

We are wondering if the SGI and the Dell have the same internals (Controller, PCB, etc.).  We know the Monoprice adapter works with the Dell, but there was a report that it didn't work with the SGI.  We don't know if this a regular occurance or if it was just one person's experience.  If the internals are the same, then it might just be a one-off that it didn't work.

[skriefal]

Here are two photos of the PCB/controller immediately above the function keys on my SGI AT101 (part # 9500900).  I may be able to get similar photos from a Dell AT101W tonight or tomorrow.

[skriefal]

Here's the Dell AT101W.  It's nothing like the SGI AT101:

[itlnstln]

Skriefal, thanks for opening those up.  When were both of those produced?  Looks like I might need to do a test on the SGI with the Monoprice adpater.

[IBI]

I own both keyboards.  Are you asking to test them with the "blue cube" or with the Monoprice adapter?  I do have one of the blue cubes available as well as one or two other PS/2->USB adapters, but none from Monoprice.

Ideally we want everyone to test every keyboard they've got with every adapter they've got and report the results so we can come up with one that works with everything. In this case though testing the SGI AT101 with both adapters would answer the point at hand.

[skriefal]

Skriefal, thanks for opening those up.  When were both of those produced?  Looks like I might need to do a test on the SGI with the Monoprice adpater.

This SGI AT101 has a May 1995 build date.  I forgot to note the build date of the AT101W.

[genegold]

After the behavior described at the end of my last post, I RMA'd the motherboard for replacement and then hooked up my three year old K8 board (MSI K8NGM2-FID).  The IBM keyboard now works without any problem so far off the PS/2 port(!), as well as, with adapter, the USB ports.  That suggests to me it was either a bad Gigabyte motherboard or poor engineering.  Hopefully, the first.

Back again.  Motherboard replacement arrived. Plug the IBM 1391401 keyboard directly into the PS/2 keyboard port and it works fine from cold computer. Try starting from ~30 seconds to a minute or two after shutdown and computer won't power up, like before (adapter/USB no different). Wait 25 minutes, as I just did, and it starts fine.  Guess that's cold enough.  That leaves either motherboard design/testing (hardware, BIOS, ..?) or PSU.  Since the keyboard worked with a three year old K8 board no problem, I would guess that rules out the PSU, but what do I know.

The key hardware is:
- Gigabyte GA-MA790X-UD4P
- AMD Athlon 64 X2 7750 Kuma 2.7 GHz Dual Core Black Edition
- Corsair VX450 PSU
(all new)

[genegold]

Putting aside the keyboard for a second, the other idea is to really check the system power.  It's clearly only an issue under load so maybe try running SuperPi or Prime95 and then take a voltmeter to a power connector and check for whether you're getting true 5V and 12V.

Only other idea is that the particular Model M you have is really corroded or something and is drawing more power than usual.  Once again, I don't believe it's a common problem or a whole bunch of people around here would be complaining about their boot ups.

Since it's the second M keyboard that's had a problem with this mb/PSU combo, I just decided to RMA the PSU.  Should have a replacement within a week.  I've also got a new monitor with USB ports coming and wonder if that would have any effect or just be like the USB hub weirdness last time.

[genegold]

Replacement PSU today.  Good news is that the problem seems to have disappeared, at least so far (1391401 into PS/2 port).  I'll qualify the PSU as the solution by saying at the same time I moved the mb from cardboard to case and hooked up all the case switches and fan.  Don't know if having those around changes the whole kb-mb interaction vis a vis residual current/capacitance.  The bad news is the wiring inside the PSU hits its fan.  I moved it around to kill the tapping, but I'm not sure that's a viable long-term solution yet.

[genegold]

OK, a couple of ways to fix that power supply.  Be safe - the caps in there can knock you on your butt or worse.

Thanks, I'll bookmark that.  The problem seems to be the placement of the cables inside relative to the fan, since moving it around a bit from the outside got rid of the tap.  Have to look in daylight.  Certainly don't want to give up a PSU that's got the keyboard working right.

[Qwertyuiop]

I may be wrong, but in the pic of the SGI AT101 PCB, it looks like capacitor C5 is bad or damaged. I wouldn't expect to see the "inner cylinder" sticking out as it is on the right side.

[Qwertyuiop]

I see. I've never seen one that's like that before that's by design; I've seen it on radials where physical stress on the cap has pulled a section out the bottom and it looks like that.

[genegold]

Whew, that was a lot of work - we're getting close to 100 posts on this. Kudos to the unnamed Geekhack trio:

Hope you're enjoying those Model M's now!

Thanks to everyone for suggestions, comments and patience.  It feels anticlimatic after all this to find that the problem was the PSU.  In any case, I have been enjoying the Model M, and now without having to wait between restarts.