Bug#900399: More good news

2018-08-11 Thread ydirson
severity 900399 normal
thanks

I suggest you get some advice from the forum[1], and as Dmitry mentionned, 
bring the issue to Lenovo.

[1] 
http://forum.canardpc.com/forums/73-Memtest86-Official-forum?s=1407c99a4da914ef85e60c32c658ba16

- Mail original -
> De: "Сергей Коган" 
> À: 900...@bugs.debian.org
> Envoyé: Jeudi 7 Juin 2018 15:26:43
> Objet: Bug#900399: More good news
> 
> Hi!
> 
> Let's lower the severity of this bug and flag it as unverified.
> 
> Given the datasheet for the TB62501 and actual board layout of the
> T500
> - the described scenario (short from the VCC3SW to GND caused by a
> stray
> write to the PMH register) is highly improbable:
> 
> - The LDO inside the RINKAN has an over-current protection set as low
> as
> 55mA and should prevent any damage even if the VCC3SW is shorted.
> After
> the single over-current/under-voltage event, RINKAN LDO is locked in
> the
> OFF state and requires a complete power-off to restart.
> 
> - Unused pins of the PMH are in fact floating
> 
> - Some RINKAN batches do show tendency to malfunction with no
> apparent
> reasons. The main board temperature could be a contributing factor.
> 
> So, we have to seriously consider the possibility that two laptops
> died
> at the same time just by a coincidence.
> 
> We do plan to run a memtest on the restored laptop using a current
> measuring/limiting circuit on the VCC3SW bus. If no excessive current
> consumption would be detected - the memtest has nothing to do with
> the
> issue. If an excessive current during the test would be observed, it
> would get us a direction to resume the investigation.
> 
> ---
> Sincerely yours,
> Sergey Kogan
> 



Bug#900399: More good news

2018-06-07 Thread Сергей Коган

Hi!

Let's lower the severity of this bug and flag it as unverified.

Given the datasheet for the TB62501 and actual board layout of the T500 
- the described scenario (short from the VCC3SW to GND caused by a stray 
write to the PMH register) is highly improbable:


- The LDO inside the RINKAN has an over-current protection set as low as 
55mA and should prevent any damage even if the VCC3SW is shorted. After 
the single over-current/under-voltage event, RINKAN LDO is locked in the 
OFF state and requires a complete power-off to restart.


- Unused pins of the PMH are in fact floating

- Some RINKAN batches do show tendency to malfunction with no apparent 
reasons. The main board temperature could be a contributing factor.


So, we have to seriously consider the possibility that two laptops died 
at the same time just by a coincidence.


We do plan to run a memtest on the restored laptop using a current 
measuring/limiting circuit on the VCC3SW bus. If no excessive current 
consumption would be detected - the memtest has nothing to do with the 
issue. If an excessive current during the test would be observed, it 
would get us a direction to resume the investigation.


---
Sincerely yours,
Sergey Kogan