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38 Posts

08-30-2018

Singapore

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  • Message 11 of 96

USB-C port not working on YOGA S740

2020-03-11, 15:24 PM
I had this issue with the older bios versions as well. Usually reflashing the same bios version would make the problem go away for a while. You don't need to flash an older version.
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3 Posts

12-16-2019

Denmark

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  • Message 12 of 96

Re:USB-C port not working on YOGA S740

2020-03-14, 19:15 PM
Missed your reply. But will give this a try. Just installing the newest bios when it happens again
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17 Posts

03-13-2020

United States of America

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  • Message 13 of 96

Re:USB-C port not working on YOGA S740

2020-03-16, 13:45 PM

Same problem here with Windows 10 Pro version 1909 and BIOS BYCN31WW. How can I get a hold to the previos BIOS version to fix this problem?

 

Mauricio

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11 Posts

03-17-2020

Italy

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  • Message 14 of 96

Re:USB-C port not working on YOGA S740

2020-03-17, 7:43 AM

Same issue here... I confirm that reflashing the same BIOS version solves the issue.

You need to enable the rollback from the BIOS to reflash the same version too (see @Tscherny post).

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11 Posts

03-17-2020

Italy

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  • Message 15 of 96

Re:USB-C port not working on YOGA S740

2020-03-17, 7:48 AM

If anyone is still interested in old BIOS versions, here's the download links:

BYCN26WW https://download.lenovo.com/consumer/mobiles/bycn26ww.exe

BYCN29WW https://download.lenovo.com/consumer/mobiles/bycn29ww.exe

BYCN30WW https://download.lenovo.com/consumer/mobiles/bycn30ww.exe

BYCN31WW https://download.lenovo.com/consumer/mobiles/bycn31ww.exe

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1 Posts

03-18-2020

United States of America

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  • Message 16 of 96

Re:USB-C port not working on YOGA S740

2020-03-18, 0:49 AM
I have a similar issue I just purchased two weeks ago and IdeaPad s740. I plugged in an external monitor to it today on the USB C port and the whole thing went haywire. Disconnect and reconnect chime sound is stuck in a loop and just keeps recycling every 3 seconds. There is no power to the USB C ports and in the display screen where it shows you the display pixels it blinks every time the connect Chime sounds. Not sure if it's a hardware issue at this point for a driver issue. I updated the driver to the Thunderbolt HSA component and that is not worked.
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5 Posts

03-25-2020

Germany

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  • Message 17 of 96

Re:USB-C port not working on YOGA S740

2020-03-25, 9:47 AM

Hi,

 

I seem to have the same problem with BIOS version 30 and 31. Reflashing does work for a little while. Don't know what happens in the meanwhile that it makes it malfunction again.

 

Now downgraded to v29, let's see what happen.

 

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12665 Posts

11-30-2015

Philippines

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  • Message 18 of 96

Re:USB-C port not working on YOGA S740

2020-03-25, 12:48 PM

Hi Jackenn,

 

Greetings.

 

I was thinking if it was the BIOS update that created the issue, then perhaps using the BIOS backflash option in the BIOS maybe an option.

 

I suggest you call in technical support to have you assisted with it if this is also an option they would also provide for you.

 

A copy of the old BIOS should be available aside from enabling backflash under configuration tab.

 

I hope this helps answer your query.

 

Regards

 

 



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5 Posts

03-25-2020

Germany

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  • Message 19 of 96

Re:USB-C port not working on YOGA S740

2020-03-31, 18:51 PM
After downgrading to v29 I do NOT have problems anymore!
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5 Posts

03-25-2020

Germany

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  • Message 20 of 96

Re:USB-C port not working on YOGA S740

2020-04-09, 7:45 AM
Maybe that was too soon. Now 14 days later, I have the same problem again. >Guess I'll need to reflash the bios again with v29
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