Rescuing a damaged USB connector on the large Linnstrument.

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KVRer
14 posts since 14 Oct, 2015

Post Thu Jul 08, 2021 3:49 am

Hi,
I just wanted to share this little hack I made for my Linnstrument...

Yesterday, I noticed that the USB-B connector was wobbly so I decided to open the device and discovered that the two pads on both sides of the connector were damaged. I always use the LInnstrument on my desktop but the USB cable was probably too short and must have been pulled very hard at some point. As a consequence, the pads attaching the SMD USB connector have been ripped off from the PCB and the USB connector is now retained only by the four remaining pads on its back (data and power).

Also, the copper trace between the right leg of the connector and R23 was cut. This pad is apparently connected to GND through this resistor. I read on the F.A.Q that this kind of damage on the units below #700 would require replacement of the whole board (my Linnstrument is a #200ish, it's an old one). Before contacting the support, I tried a quick fix. I'm not sure if I could have used some epoxy resin to re-attach the connector in place. Instead, I used a 3d printed part to help maintaining the USB socket on the PCB without destroying the remaining traces.

First, I re-soldered the right pad to R23 with a small piece of wire. Then I 3D printed a small block to hold the USB connector in place. It cannot swing between left and right anymore, it leans on the Jack connector on one side and on the DIN connector on the other side. Hopefully it won’t move up and down either, the 3D printed block and the USB connector will be pushed against the PCB by the bottom of the enclosure. And from front to back, unfortunately there ain't much elements to rest on, I added a 1.5mm extrusion to lean on the jack connector on the right. The 3d block is cut to avoid crushing the resistor and the capacitor nearby (and the little wire used to repair the connection between the connector and R23)

I could probably drill a hole on the bottom enclosure to screw the 3d block if necessary but... :-/

It seems to work as expected but I’ll be extra careful with this connector from now on.

In case this little hack is useful to anyone, you get the idea on the photos attached. It seems I can't upload the .step files directly to this forum unfortunately but I'm happy to share the details if needed.

Caution: once the 3d printed block sits in place on the USB connector, it’s difficult to remove it and this could cause further damages.

Best,
Matt

Linnstrument damaged USB.jpg
linnstrument USB fix.jpg
step_Linnstrument3D_V3.jpg
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Last edited by Elberstein on Thu Jul 08, 2021 4:03 am, edited 2 times in total.

KVRer

Topic Starter

14 posts since 14 Oct, 2015

Post Thu Jul 08, 2021 4:02 am

For the sake of completeness, here's a photo showing:

- in green the undamaged data and power traces on the back of the connector. Fortunately, these were not destroyed.

- in red the broken connection between the right pad and R23 (and also the damaged pad on the left). It's hard to tell, but the copper pads are completely disconnected from the printed circuit board.


Be super careful with the USB connector of the Linnstrument to avoid that kind of DIY repair :-)

IMG_5737.jpg
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KVRAF
1787 posts since 8 Jun, 2010
Roger Linn Design

Post Thu Jul 08, 2021 6:31 am

Hi Elberstein,
Very creative solution! If others encounter this problem, my normal solution is to fix it for $100.

KVRer

Topic Starter

14 posts since 14 Oct, 2015

Post Thu Jul 08, 2021 8:47 am

Thanks Roger Linn,
Yes, if the 3D solution is not solid enough, I will certainly order a new (or repaired) PCB from you.

Also, I've been meaning to get the most recent top panel for a few years now, perhaps could I combine shipping to Europe for these two items ?

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KVRAF
1787 posts since 8 Jun, 2010
Roger Linn Design

Post Thu Jul 08, 2021 9:36 am

Sure— email me at the support address and we can handle it directly. The online store doesn’t handle combined items well.

KVRer
6 posts since 8 Jul, 2019

Post Thu Jul 22, 2021 9:41 am

USB L-Shaped.jpg
I found this adapter useful. It allows me to fit a trackball tidily alongside the LS and separates in case the cable gets yanked, etc. Described as "USB L-Shape Extension Cable (B-Type L-Shape Male ← B-Type Female)"
Best to find one that bends in the right direction, so the cable feeds towards the rear. (It does cover the foot-switch input in that orientation.)
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KVRAF
1787 posts since 8 Jun, 2010
Roger Linn Design

Post Thu Jul 22, 2021 9:51 am

Right-angle and left-angle cables such as you suggest can be helpful, but they only change the type of hard cable pull that can cause damage to the jack. The more common pull is straight out, which won’t cause damage with a normal USB cable end but will cause damage with an angled cable end.

The best protection is what I suggest on the Hooking It Up page: tie the USB cable around the nearest guitar strap button to act as a strain relief.

KVRer
6 posts since 8 Jul, 2019

Post Thu Jul 22, 2021 10:32 am

The 1-piece L-shaped cable is more vulnerable in straight pulls, but less so if it's a short extension only, as it would just separate in pulls along that line, I imagine. I find it provides a little more leeway in my keyboard tray which doubles as a LinnStrument stand. That's about it.

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