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9 Posts

05-12-2019

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  • Posts: 9
  • Registered: ‎05-12-2019
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  • Views: 40
  • Message 11 of 11

Re:ThinkPad T470s BIOS bug - WOL and Thunderbolt 3

2020-06-21, 20:28 PM

I have a similar problem with my T450s. Current BIOS is JBET73WW  1.37  14.08.2019

Apparently, the second battery (external) fails to power the computer, but it does take charge.

An attempt to boot with both batteries installed result in a never ending boot loop. If I enable WOL, it does progress beyond POST, but then reboots again.

On AC, it boots just fine, and on the internal only battery, it also boots just fine.

If I boot on AC with both batteries installed and then pull the plug after successful boot, the PC tuns off immediately, even though both batteries are fully charged.

If I disconnect the internal battery, it doesn't even try to boot. No lights, nothing.

 

All Lenovo battery and motherboard diagnostic tests has been run successfully. No errors reported.

 

The issue does not follow the batteries. Both batteries have been replaced, but to no avail.

 

I suspected that it might be that the Power Bridge failed, but I do not have enough knowledge to debug that path.

 

I will try to downgrade the BIOS to check if that helps.

Any advice is highly appreciated.

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