Northgate Omnikey 102 - technical help needed!


17 Jun 2020, 12:36

This is my first ever post here, so hi guys! :)

So far, after about two months into mechanical keyboards, I’ve been learning a lot here on deskthority and was able to solve two or three problems by just reading posts and trying things out. Now I’ve come across a problem that I could use some help with:

So I recently bought a set of two Northgate Omnikey 102s on Ebay Kleinanzeigen (german small-scale Ebay thing), both with vintage white alps, one from 1988 with the dip switches at the back, one from 1993 with the dip switches at the top, below the label.

The seller explicitly sold one of them as working and the other one as defective. He didn't specify how severe the defect was, but I felt like I couldn't waste any time with asking for specifics and risk missing out on the good offer. On top of that, I figured that even if it would turn out to be completely dead, I could still salvage possible future replacement parts for the other omnikey from it. Now that they've finally arrived (yeah!), one is working fine as expected and the defective one, which btw is the 1993 one, is luckily not dead at all, just, well, weird:

When it is connected and the pc starts up, all the lock lights flash once as usual. Then, when my debian is booting, they (most of the time, though not always) go into a state of continuous blinking, synchronous and at an interval of about every two seconds or so. During this state no key presses take effect, but they appear to be registered on some level, because if one or several keys are being held down or are pressed in quick succession, the blinking stops, only to continue half a second or so after releasing the key(s). So in other words, this temporarily stops the actual blinking, but not the special state. Sometimes the blinking state stops by itself after a few minutes, sometimes rebooting leads to the keyboard behaving normally. Normally in this case means that everything works totally fine - unless either caps lock or num lock is pressed - doing so immediately (re-)triggers the blinking state as described above. Now these are of course not exactly the most vital keys in the world, but I’d still like to completely fix the board, if at all possible.

So far, I have carefully cleaned the pcb of stains and dust, looked for obvious broken traces, got as much dirt out of the board as possible, tried if the dip switch unit might be broken, tried attaching the cable of the other omnikey etc. Unfortunately, so far none of this has solved the problem. Now I think it might be either the controller or a capacitor, but at least visually all components look fine, no corrosion or anything like that. Only thing I noticed is that the controller gets quite warm, but that might be normal, I haven’t yet had time to check if this is the same in the other Omnikey.

Do you guys have any idea what else I could try? Or has someone maybe experienced something similar, possibly even also with an omnikey?

Many Thanks in advance!

User avatar

18 Jun 2020, 06:25

Welcome, and congrats on the Northgates. Nice keyboards, I own several myself. Switches on the back edge is what I call a second generation Northgate, or Gen2. Switches under the badge would be a Gen3. Both of those versions had several different modes, which are selected by the dipswitches. Some of the switches move keys around - Caps Lock, Control, Dvorak layout (!), and so on, while others select the specific computer it's configured for. So first you need to check the switch settings to be sure it's set for AT/PS/2. This is the manual for the Gen3: ... 201991.pdf

Since it's inconsistent you might try turning all the dipswitches on and off a few times in case the contacts are dirty, then move them back to the proper settings.

Post Reply

Return to “Workshop”