It is highly unlikely that the once working, the driver just stopped working. (Very rare) and is more likely a setting in the keyboard, especially since neither your PC nor your Mac is seeing the device. At least let's start with this premise as it is rare to have a non-functioning connection. After we check the settings, next suspect is the cable itself - cables do go bad, as well, so have handy another USB cable to try. (Short as you can - extra long USB cables have problems before shorter ones, and avoid extensions whenever possible).

As with any computer related issue, let's start with the specifics - version numbers are extremely important especially for drivers.

On the Windows 10 side, the driver you should have installed is the Yamaha USB-MIDI driver version 3.1.4 for Windows
You have a 32-bit and a 64-bit version. Which is you Windows 10 computer operating? Download the appropriate one and install it.
You can verify and check your version installation by navigating to your Windows 10 CONTROL PANEL, the driver should be listed under "Hardware and Sound"

Make sure your S70 XS is set to MIDI IN/OUT = USB

On the Mac side the driver is the Yamaha USB-MIDI driver version 1.3.4 for Mac. You should see its icon when you go to System Preferences > Others
Again make sure your S70 XS is set to MIDI IN/OUT = USB

Press [UTILITY] > select "MIDI" > on page 1/3 find your current MIDI IN/OUT status, make sure it is set to USB.
Press [STORE] to write this to your instrument Flash ROM.

Let us know.

Thanks, Bad Mister for the above detailed explanation.

I have installed the 32-bit version on Windows 10 as per my laptops specification.
I have tried three different USB cables of different lengths (without extensions) starting from 1 meter length.
The MIDI IN/OUT on S70xs is set to USB.

For the versions of the installed drivers I will check and let you know once I get back home.
I tried the Keyboard on my friends windows 8.1 laptop after installing the required/provided driver on Yamaha website. But the same issue 🙁

Thanks for the support. I will revert to you in 5-6 hrs with the version numbers.

The drivers installed are
Win 10 : USB-MIDI Driver V3.1.4 for Win 32-bit
I-Mac : USB-MIDI Driver V1.3.2 for Mac

On Win 10 the keyboard is not shown under Device Manager too. All the USB ports of the the laptop are functional. No windows sound while the S70xs is connected. Meaning, doesn't detect connection of the S70xs.

On the Mac I could connect the S70xs thru the M-Audio Sport Uno midi interface/cable. I could record and playback midi using S70xs as an external midi device. The S70 xs editor failed to connect as it doesn't detect the S70xs 🙁

I tried all the possible thing on Windows 10 Laptop10. All usb port drivers are updated. I removed their power saving mode. Still no luck 🙁

No device is connected. Connect a device, and try again. If the “Found New Hardware” wizard appears, push the “Cancel” button.....

This is the error message that I get on Windows 10 when trying to install the Yamaha USB-Midi Driver.

Hope to find a fix very soon. Been browsing and have realized that its a common issue but haven't come across a solution that has worked for me.
Please guide me.

On the Mac I could connect the S70xs thru the M-Audio Sport Uno midi interface/cable. I could record and playback midi using S70xs as an external midi device. The S70 xs editor failed to connect as it doesn't detect the S70xs 🙁

Sorry, I don't know what you mean by this. MIDI is working as you can record and playback using the S70 XS as an external device?? Please explain. What is an m-audio Sport Uno? That will not work for the Editor, but I guess your trying anything.

The Editor does not detect anything (ever) you must select the appropriate USB driver in the Editor's Setup screen. And the Editor must use a direct USB connection to the S70 XS, not the 5-pin MIDI jacks. The Editor requires multiple Port communication. So please change MIDI IN/OUT back to USB.

Again: When you go to Windows Control Panel > Hardware and Sound > do you see the blue "Yamaha USB-MIDI" icon?
Again: on the Mac when you go to System Preferences > Other > do you see the blue "Yamaha USB-MIDI" icon? And please update to 1.3.4

Let us know.

Yesterday, on the Mac I initially tried connecting using the USB cable. In the Editor' set up screen we get to select the In and out Ports but it did not list the S70xs. Till this point of time the MIDI IN/OUT was set to USB on S70xs.

Later I changed the set up to MIDI just to check if it was transmitting any data from the keyboard. This time using the M-Audio Sport Uno midi interface/cable which is 5-pin MIDI jacks. I tried this opening Logic X using External device/instrument midi track. Sorry I wasn't clear earlier.

Ive changed the MIDI IN/OUT setting back to USB now

Yes on both, the laptop and I-Mac the "Yamaha USB-MIDI" icon is available.

From where do I get V1.3.4 for Mac. On Yamaha website under S70xs I only found V1.3.2

With your experience of troubleshooting so many cases on daily basis, what/where could be the problem be in my case.
It's really frustrating and killing me. I love the Yamaha S70xs. A very friendly user board and the Editor which made my experience exciting and interesting for three and half years; since the time I bought this board. Never faced such issues before. Its my first Yammy.

Do you think it's with the Keyboards hardware? Should I take it to the service centre (which I don't want to)? On youtube Ive seen a video where a person fixes his midi keyboard problem by changing the USB-B socket.

As you said in your first reply I too feel the same that it has got nothing to do with the hardware. But it hits me every time when I tell myself that I have already tried it on three PC's. Two windows Laptop Windows 8.1, Windows 10 and one I-Mac 🙁

Yes on both, the laptop and I-Mac the "Yamaha USB-MIDI" icon is available.

Double click on the blue "Yamaha USB-MIDI" icon to open the Control Panel.

No, I'm not quite ready to send you to the shop, not yet. We have not exhausted our tests. It may well be a damaged jack, but I can't conclude that quite yet.

I have attached for your reference

Sorry the file size exceeds the limit set.

Anyways, I double clicked on the "Yamaha USB-MIDI Driver (WDM) in Control Panel and it pops up a message "Yamaha USB-MIDI Device is not connected."

Please note that while trying to install the Driver I get this error message "Error 25001. No device is connected. Connect a device and try again. If the "Found New Hardware" wizard appears, push the "Cancel" button"

Today I tried the keyboard with the software called MIDI-OX just to see if it is transmitting any data thru USB. It didn't transmit nor detect the connection. But when changed it ti the 5pin jack and the setting on the keyboard it transmitted the data.

Does this conclude that it is an issue with the Keyboards USB jack?

Only if you're confident that you've made the appropriate settings in MIDI-OX... It really does seem to point to an issue with the To Host USB port.

In MIDI-OX I went to MIDI DEVICES under Option menu but nothing was available under MIDI INPUTS panel to select.

I will keep you updated with my scene. Thank you Bad Mister for your time and support until now. I realy appreceiate it.

Hi Bad Mister. I want to update you on the keyboard.

The Service Centre called and informed me that it is the problem with the DM Board WQ357200 which needs to be replaced and it will cost me KWD 285 (250+35) which is approximately US$ 950. When asked what could be the reason the Service Manager tells me “Could be due to ‘HEAVY USAGE’ “. You tell me Bad Mister, I am in a country (Kuwait) where LIVE PERFORMANCES are restricted (more like prohibited) and RECORDINGS is more like ‘DEAD’. Therefore what heavy usage is this guy talking about? I’ve owned it for 3 plus years wherein I have hardly used and now having issues with it’s DM Board.. (I was explained that it is the motherboard)

I’m sad and disappointed. I thought Yamaha keyboards were robust but they aren’t. Now I even feel that I should have gone in for the SV-1 or Kronos (which would have been my second KORG). I fell in love with the S70xs watching Mr. Bert Smorenburg’s youtube review/demo. But the way this Manager spoke to me made me realize that what matters to Yamaha or the agent is the SALES and nobody cares about AFTER SALES SERVICE. I put in my savings to buy a good board with an unique concept… for it to only backfire me. This should not happen to anybody else. The manager tells me that it is my ‘BAD LUCK’. A joke or am I a fool? I do not know.

I have lost the trust with YAMAHA and don’t think I will ever buy another Yamaha product nor suggest any musicians. Yamaha keyboards sound good but the machines are not robust. Guys like me cannot afford to buy another board nor these repair costs. The world has advanced in technology but here we are unable to prevent whatever the cause could be that damaged the board... that part of the DM Board (USB to Host port) cause rest of it is functioning… but I seriously feel that someday that too will spread like cancer and die.

I thank you Bad Mister for being with me. Guiding/replying my queries on daily basis. I am sorry that I got a little senti and expressed my views… thoughts… I am attached to my instrument/gears. The manager referred or made it sound like just an ‘Electronic Device’ and anything can happen. I know it is an electronic device but one should never say that to a musician. We bond/connect with them. I know I sound OLD SCHOOL.

Thank you once again and Good Bye Yamaha.