Picked up an FK-5001 and it has a strange issue

[Red_October]

So I saw on eBay a Focus FK-5001 going for $60+S&H, I shot the guy an offer of $40 and he bit, so, well, now I've got an FK-5001. I was lucky in one respect, it had never had the little plastic insulator taken out from the battery compartment so when I opened it in hesitation to see if I had to address any green death, I discovered a nice, shiny 2032 and a little clear plastic bit that fell out. I put the battery back and the calculator immediately sprang to life. I connected it to the PC with a pair of adapters (DIN-5 to PS/2 and PS/2 to USB) and gave the thing a shot. It seems to work pretty well but there is a very strange issue that would hamper any actual, well, use of the keyboard. Pressing the NUM LOCK key basically kills the keyboard. The NUM LOCK light does not light (nor does it respond to the pressing of a NUM LOCK key on another keyboard) and the keyboard immediately stops responding to keypresses. The calculator section stays live and can be switched on and off with its keys (this is the later version without locking keys). I've cleaned the NUM LOCK switch with CRC Chemical's QD contact cleaner (after an abortive attempt with MG Chemical's Nu-Trol which is specifically control cleaner but its lubricant robs the switch of its click! This happens with other clicky switches so beware! It seems that Radio Shack got a lot of their chemicals from MG and their contact cleaner was/is this, so if you are near one of the few remaining Rat Shacks or come across a stock of it, beware this!) but this did not do anything. I took the keyboard apart and cleaned all the contacts of the connections as well, but it was remarkably good inside, with just a little bit of fluff and no corrosion evident anywhere. Has anyone any insight into this problem? Where do I begin looking and what do I begin looking for?

[SneakyRobb]

Hi,

I seem to recall Chyros having a somewhat similar issue with the P70 alps plate spring.

https://youtu.be/L60SP-hAaMw?t=117

Here it is. I am not sure why this happens though

[cli]

It seems to me all switches are fine, the keyboard reacted when you pressed the key. Are you using a Soarers PS/2 USB adapter ?

[Red_October]

It seems to me all switches are fine, the keyboard reacted when you pressed the key. Are you using a Soarers PS/2 USB adapter ?

No, a conventional one. My next course of action will be to hook it directly to a machine which requires no adapters and see what that does, and also to test in XT protocol mode as that machine is such.

[Polecat]

So I saw on eBay a Focus FK-5001 going for $60+S&H, I shot the guy an offer of $40 and he bit, so, well, now I've got an FK-5001. I was lucky in one respect, it had never had the little plastic insulator taken out from the battery compartment so when I opened it in hesitation to see if I had to address any green death, I discovered a nice, shiny 2032 and a little clear plastic bit that fell out. I put the battery back and the calculator immediately sprang to life. I connected it to the PC with a pair of adapters (DIN-5 to PS/2 and PS/2 to USB) and gave the thing a shot. It seems to work pretty well but there is a very strange issue that would hamper any actual, well, use of the keyboard. Pressing the NUM LOCK key basically kills the keyboard. The NUM LOCK light does not light (nor does it respond to the pressing of a NUM LOCK key on another keyboard) and the keyboard immediately stops responding to keypresses. The calculator section stays live and can be switched on and off with its keys (this is the later version without locking keys). I've cleaned the NUM LOCK switch with CRC Chemical's QD contact cleaner (after an abortive attempt with MG Chemical's Nu-Trol which is specifically control cleaner but its lubricant robs the switch of its click! This happens with other clicky switches so beware! It seems that Radio Shack got a lot of their chemicals from MG and their contact cleaner was/is this, so if you are near one of the few remaining Rat Shacks or come across a stock of it, beware this!) but this did not do anything. I took the keyboard apart and cleaned all the contacts of the connections as well, but it was remarkably good inside, with just a little bit of fluff and no corrosion evident anywhere. Has anyone any insight into this problem? Where do I begin looking and what do I begin looking for?

This is just a guess, and may be way off track. Some time back there was a web page about the Focus calculator models having a "calc lock" key that changed the output from keyboard to calculator to allow you to output the calculator results into a spreadsheet or other program. The person who wrote the page was trying to find a more modern keyboard with a similar feature. If the keyboard is getting toggled to calculator mode you might try playing with the other lock keys to see if one of them turns the keyboard back on.

[Chyros]

This is something you need to ask Engicoder, if anyone knows it's him.

[Red_October]

This is something you need to ask Engicoder, if anyone knows it's him.

Thanks for this, I'll shoot him a message if I can't work this out.

Anywho, I switched it to XT mode and plugged it in to my 5155 Portable Personal Computer and, Lo and Behold, it works fine, Num Lock, Caps Lock, Scroll Lock, KB Lock and Calc Lock all do not lock up the keyboard. Next step will be to connect it to an AT-protocol machine and see if that works OK, not sure if it will on my main desktop as that one's PS/2 port might be fried from my injudicious hot-plugging keyboards.

[snacksthecat]

+1 for engicoder

Definitely interested to see if he has a perspective based on your description.

If I were in your boots (and with a multimeter), I would open it up and trace out from the bad key. Try to figure out which pins it connects to. Then try to see if those pins are shorting with any other pins.

But that probably won’t work because it’s fine when you switch it to XT. So I’m confused.

One thing is clear to me, we as a human race are not ready for calculators in our keyboards. It’s over indulgent to the max. It’s like pouring chocolate syrup on a piece of cake.

Plz stay safe, OP

[Red_October]

Seems like I won't have to bother Engicoder, I connected it up to my machine's PS/2 port, re-booted and this time it works just fine as well in AT mode, lock lights and all. So for whatever reason it disagrees with the PS/2 to USB adapters I have tried, and I tried two of them (I have more but not to hand). Not sure why it should behave that way, it's the kind of adapter that's got separate ports for keyboard and mouse so it's not like the one port has to do double-duty or anything and so might have non-standard wiring, but there it is. Probably just need to find the right adapter, I don't think I'll be making this my daily driver right now as it's got a non-stepped Caps Lock key and just in the course of writing this one missive I've hit it by accident. Gotta at least see if any of my other Alps boards have a stepped one I can pilfer... My customized layouts (may the gods smile upon Hasu and Soarer) have really gotten me used to the old-style Control key placement that I started because I had an F XT and don't like it when the labels on the keys don't correspond to their functions (still wish I could find a stepped control key for the lower-right of my F122, it now says "Enter" and that's not right, lower left is a function layer key and says "Reset/Cancel" which isn't so bad). Caps Lock just infuriates me as it's stupid.