Help: Broken USB connector on Matias Mini Quiet Pro

[sandywind]

My Matias Mini Quiet Pro stopped working and after opening it I found the micro-B USB female was completely detached from its board. Apparently the connector did not survive a few hundred plugging-unplugging cycles. (At the end of every workday I put the keyboard in the drawer.)

The connector was soldered onto a rather small secondary board which is connected to the main one by 4 vertical connectors, with more than 10 pins each. Now, by experience I know that such small boards can be tricky to disconnect when there are many connectors with a lot of pins. In the worst case the needed force could damage it. (With this board, I have not tried yet.)

Has anyone tried to disassemble a Matias Mini and successfully separated the boards?

[LASERman Projects]

Someone experienced and equipped with desoldering gun should be able to do it for you.

[sandywind]

That is an option, I know someone who could lend me a desoldering gun, but I would have liked to separate the boards by unplugging the connectors. Not an expert in board engineering, but I believed that one reason to use connectors would be to service without desoldering. But it could have been the simplest way of connecting the boards, who knows.

[suicidal_orange]

Can you post a picture of the connectors?  There should be a way to disconnect them safely but can't say what it is without knowing what they are.

If it's just the pads where the USB socket goes that are damaged there is probably somewhere nearby you could run some wires to but again, can't be sure without a pic.

[Darthbaggins]

^ This, I would think there would be a way to properly disconnect the terminal from the primary PCB.  I know it's that way with a majority of my boards (don't have anything uber fancy where they took the time to solder it on the PCB directly).

[sandywind]

Disconnecting the two boards turned out to be much easier than I thought. The hard part was to resolder the SMD mounted micro-B USB female because its 5 pins were partly covered by the case of the connector. I bought a very thin USB soldering iron and exploited the fact that there is usually enough melted tin on the tip to create sufficient contact.

On the one hand, I praise Matias for using quality connectors between the boards. I connected and disconnected the two boards several times without issues. On the other: in my opinion, micro-B USB female are not a safe choice, except when they are located on the bottom of the keyboard and the cable is routed and blocked. Also, the connector Matias used has only two legs instead of four. I acknowledge that they designed the part of the case that encloses the connector in such a way that it absorbs much of the force. In my case, maybe there was enough play to break the contacts.

[tp4tissue]

it's fixable even if it's the worst case surface mount soldered. You'll just have to scratch at the pcb for copper.

[Maledicted]

Disconnecting the two boards turned out to be much easier than I thought. The hard part was to resolder the SMD mounted micro-B USB female because its 5 pins were partly covered by the case of the connector. I bought a very thin USB soldering iron and exploited the fact that there is usually enough melted tin on the tip to create sufficient contact.

On the one hand, I praise Matias for using quality connectors between the boards. I connected and disconnected the two boards several times without issues. On the other: in my opinion, micro-B USB female are not a safe choice, except when they are located on the bottom of the keyboard and the cable is routed and blocked. Also, the connector Matias used has only two legs instead of four. I acknowledge that they designed the part of the case that encloses the connector in such a way that it absorbs much of the force. In my case, maybe there was enough play to break the contacts.

Did you end up fixing it then? I have done one of these repairs to an older Matias mini board that I purchased in that condition, although I actually replaced that connector entirely with a beefy female aviator connector that I mounted to the case. With mine, most of the pads were lifted so I had to do as tp4 described and scrape the solder mask off of the traces to tap into. I covered all of the repaired connections in high temperature hot glue, so it should be indestructible now.

I don't know if it is something that they normally do, but I have been able to purchase a parts board from Matias very cheaply. They charged me $10 for the board and $15 to ship it to me in the United States from Canada. The board seemed, to me, to be working perfectly. It was just missing caps and stabilizers. Worst case, someone could possibly pick up one of these from Matias and just swap the controller.

You probably have one of the older boards that had nothing at all reinforcing the micro USB connector. I don't know when the revision was made, but newer boards have a huge plastic block screwed into the controller that locks the micro USB connector down from every angle, which I imagine resolves this problem entirely ... since it seems to have been a common point of failure in the past.

I have a thread on the subject, along with some easy modifications that can be done to these boards to change layout and LED colors.

[sandywind]

Did you end up fixing it then?

Yes I did. I am not feeling very confident that it will last longer.

I considered converting one of the USB type A, but it would have taken much more time.

[Maledicted]

Did you end up fixing it then?

Yes I did. I am not feeling very confident that it will last longer.

I considered converting one of the USB type A, but it would have taken much more time.

High temperature hot glue is a lot more resilient than people assume. It isn't like the hobby glue sold in an arts and crafts section. It is also not conductive. If there's anything I repair that I have any question about structurally, I glob as much as that stuff on as I can get away with to reinforce the the tiny pads and/or traces.

I just fixed a flash drive similarly the other day. A teacher had saved years worth of important documents on that flash drive ... and that flash drive only. All 4 pads were lifted. the +5v and ground lines had a tiny remnant of the pad (which was good because the traces were not visible on the surface), but the data line pads were totally gone. It ended up being easier to secure jumper wires to the data line traces once I scraped away the solder mask than the remnants of the pads for power. I literally had the +5v wire fall off multiple times while I was trying to hot glue it, but I dumped all of the data and eventually managed to encase the whole PCB in high temperature hot glue, so it should be stronger than new ... just really really ugly.

[sandywind]

I need to open the case once again to fix the Esc key. I'll follow your advice and glue the connector to the board.

Can one soften the glue and remove it if necessary?

[Maledicted]

I need to open the case once again to fix the Esc key. I'll follow your advice and glue the connector to the board.

Can one soften the glue and remove it if necessary?

That's one of the best things about high temperature hot glue. It can be peeled off of most smooth surfaces with some force. Sometimes if I need to get at something specific within a glob of the stuff, I carefully cut up that section with a flathead screwdriver so it has less surface area to stick to when I go to rip that part off. Once some of it is lifted from the surface, it rips off more easily. I would still be careful trying to tear it off around solder joints because it does take some force to remove. It doesn't really stick to silicone wire insulation, so using that helps if you need to go back and change things. You can melt it with a soldering iron, heat gun, lighter, etc. That can make a mess though.