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CP4 broken USB jack

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My studio is tight and as I was recording a Rhodes track behind my CP4, which had a usb cable connecting it to my DAW, I guess I hit it with my back. The cable looked a little bent and now I’m not getting any signal thru the usb jack. I tried a known good cable as well and got nothing.
I use this board extensively for touring with a thumb drive, and as a midi controller in the studio.
I couldn’t have hit it very hard but I guess I broke some connection in there. It looks fine, but yeah..not working.
Any suggestions? I’m pretty good w a soldering iron, is this within the realm of home service?

 
Posted : 12/12/2020 6:41 pm
Jason
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Normal disclaimer about warranty and dangers of DIY aside - you should be able to get on the phone with the parts 24x7 folks to see if that piece-part for the USB port is available. You'd want to extract or wick as well as you can the shield pins - and these tend to take a good amount of heat. I've got a Hakko 808 extraction gun that makes quick work of this. The same gun would suck out the solder of the data/power pins (smaller ones) as well and a gentle pull will extract the part. That's the hardest part. Getting the old part out of there. If in desperation you could snip the shield with something like this:

And use wick or conventional methods to desolder the smaller pins (data/power). These will not take long to heat and should be fairly easily extracted. The extra shield still stuck in the PCB can be "pushed out" with the tip of an iron which is easier to do when the rest of the pins/etc are free and gone.

I'd use the Hakko because I have it. It's the best tool for extraction I own.

Going the other way is relatively easy. Make sure you apply enough heat on the shield pins to get a good bond. Not only does the solder need to melt - but the metal in the PCB and metal of the shielding needs to be at a high enough temperature for everything to weld together.

It probably wouldn't cost that much if you bring the parts to a tech. There's no diagnosis involved if you're convinced it's the port and not some other damage to the PCB due to mechanical stresses of the USB port acting as a lever when you ran into the plug.

You may want to ohm a few things out (continuity test) to see you have good connectivity between the power+data pins and where these lines go. You can also test power at the end of a USB cable connected to see if those are good. But if there's a cracked PCB - it may be intermittent. Visual inspection may or may not uncover this.

 
Posted : 12/12/2020 8:12 pm
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Thanks! It’ll be tomorrow before i can dive in. Hopefully I haven’t cracked the board. It wasn’t a violent hit and it doesn’t look bad visually so I’m optimistic

 
Posted : 12/12/2020 10:07 pm
Jason
Posts: 7912
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Levers are built to take a small force and exert a large one near the fulcrum. If you have a long/rigid lever attached to your keyboard then it doesn't take that much force on the very end of the lever (USB cable housing) to exert the "amplified" (mechanical advantage) force to the connector which, due to welding on the PCB, is transferred fairly readily to the PCB (unless otherwise constrained). Looking at the PCB I do not necessarily see provisions for such mechanical restraint and doubt the chassis does this on its own (metal not thick enough to serve as a "wave guide" - using loose terms here - and hole not small enough to prevent USB cable from "hinging" at the chassis as the fulcrum.

Just laying out possibilities here. Stuff to look for when you crack open the case if you decide to do this yourself.

Even out of warranty - using a tech may be better to transfer liability from you to someone else.

But if you're proficient enough - then this isn't the most difficult rework in the book. Depending on what you find, you may be looking for a replacement PCB instead of doing the connector rework. The typical fix would be to just swap out the PCB with USB connector and call it a day. That can be expensive though - the USB connector is on the DM board - around $320 USD. https://www.fullcompass.com/prod/546404-yamaha-ze951000-dm-pcb-assembly-for-cp4

So I can get why the $5ish USB connector would be a preferred fix. And if you get a quote >$320 for the job, you pretty much know the route the tech is taking. Which, in the end, is a better use of time considering the possibility there's a PCB failure and not (only) connector damage.

I guess before doing anything double and triple check there isn't a simpler reason why USB data isn't getting through. You did the cable test. A few other sanity checks on setup.

 
Posted : 13/12/2020 5:14 am
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All that about outlines my own thinking on it. I’m a vintage keyboard tech. I rebuild and work on Wurlitzer electric pianos, Rhodes, etc. as well as the odd tube amp, etc. much bigger circuits generally. I have repaired a few flat screen tv’s in my time, and I’ve had to pull my nord apart and do tour fixes. I’m gonna at least get a look at this thing. Oh was tracking all day again today so I haven’t had a chance to open it up.

 
Posted : 14/12/2020 3:14 am
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Aaaalright. Got it open. Jason, you nailed it.
What has happened is the inner black part of the port was pushed in and the two pins broke. It’s come free of its metal housing. Assuming I can find the right part, and get the board out, replacing it doesn’t look outside of my capabilities.
What I am afraid if is detaching these 4 ribbon cables. They don’t look to be on hinged connectors. Is it possible they just slide out with bare ends?? I’ve detached many a ribbon cable in my time but I’ve not seen ones like this that don’t seem to have a connector on the end. I dared not pull in either the black part or the ribbon I’m calling my local Yamaha shop tomorrow, but what can you guys tell me about these ribbon connectors? Thanks for wonderful info so far.

 
Posted : 14/12/2020 5:33 am
Jason
Posts: 7912
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I don't have the service manual to try to identify which parts are used here. They (service manuals) can be ordered. I can't remember if connectors would typically have MPN or not - which would give you information about the interconnect. The service manual can have disassembly instructions for the service techs.

 
Posted : 14/12/2020 8:16 am
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