deskthority

Ok so my Model F XT's phantom keys issue came back, and I finally tracked it down to the DIN connector itself. First, it doesn't even look stock. It looks like the connector was replaced at one point as IBM never used this. Also, it looks like it was soldered by Helen Keller, and far too much heat, no pre-tinning, no flux, nothing. It was a hack job. And then on top of it, the RF shield ground wasn't even soldered, just left floating between the insulation and the metal clamps which were not even crimped. It was hanging off the soldered wires this whole time. No wonder the keyboard had random phantom keypresses.



Here's a pic with the unrepaired connector on it, the new connector replacing it, and my Soarers which just happened to be in the shot since I was prepping to test after repair.



While inside, I did make an interesting discovery about my Model F XT. This is not the original cord to this keyboard. This is a Type 2 Model F and does not use the reset pin, yet the cord has 5 wires. Also, it's clearly a Type 1 cord as those come coiled straight out of the keyboard (no straight cord before the coil, and no strain relief grommet as well). Well, sometimes Type 1's come with metal DIN's from the factory (Type 2's had the common IBM molded plastic DIN with the IBM logo, but some Type 1's have it). Since this is a Type 1 cable, then the metal DIN connector I used is perfect, and based on some photos of Type 1's with metal DIN connectors, my new connector looks identical to the one used by IBM, so this is perfect.



I can now say with absolute certainty, the issue is now fixed. No amount of shaking of the cable has yielded any issues. I call this repaired, and might I say since it's been cleaned, with a new factory looking Type 1 style connector, restored? (Even though it's actually a Type 2 with a Type 1 cable installed)

Well, I think it looks good.

Thanks much for posting this. I was introduced to the world of properly grounding Model F keyboards a few weeks ago and it's really great to go from, "This is terrible! I'm going to have to buy a new controller!" to, "This is perfect!" in the space of a couple minutes.

hellothere wrote: 28 Aug 2020, 19:24 Well, I think it looks good.

Thanks much for posting this. I was introduced to the world of properly grounding Model F keyboards a few weeks ago and it's really great to go from, "This is terrible! I'm going to have to buy a new controller!" to, "This is perfect!" in the space of a couple minutes.

Yep, Model F grounding is hugely important. Heck, wiggling the USB connector is enough to make a Model F go nuts in my experience, just from the USB connectors grounding rubbing against the contact it's pressing against.

What DIN5 connector is that? It looks a lot like the plug on my Unitek K151L (a shameless F AT clone), only with a satin finish. I can only imagine it's meant for making premium MIDI cables.

Rayndalf wrote: 28 Aug 2020, 21:01 What DIN5 connector is that? It looks a lot like the plug on my Unitek K151L (a shameless F AT clone), only with a satin finish. I can only imagine it's meant for making premium MIDI cables.

It's a Rean branded cable. Meant for audio use but was only 6 bucks shipped on eBay so I couldn't really pass it up. It looks like an early Type 1 Model F connector which were also metal and looked identical (minus the gold plating): https://vintagecomputer.ca/wp-content/u ... bottom.jpg
(Apparently according to that site not all Type 1's had a metal plug, but the ones that do look exactly like the DIN connector I purchased, and since it's a Type 1 cable that's installed on my Model F, I figured why not.)

Bought it here: https://www.ebay.com/itm/Neutrik-Rean-N ... 4172052553

The strain relief on my K151L is tearing, so it's good to know I can get a perfect replacement for $6

Rayndalf wrote: 29 Aug 2020, 01:15 The strain relief on my K151L is tearing, so it's good to know I can get a perfect replacement for $620200828_181125.jpg

Yep. It's not chrome like the original, it does have a little texture, but you wouldn't notice it unless you looked closely, and it's of higher quality than OEM anyway.