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.
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Sincerely yours,
Sergey Kogan
