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Old 07-03-2020, 09:38 AM   #1
ktmmotocross
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Default Lenovo E480 no sign of life

Hello have this Lenovo E480 that after storm wont work
NM-B421

two chargers USB-C dont give me voltage. so i cut one and with cable connect my source and see 2.7W steady. Found hot area near power connector with burning resistor. it is so tiny that i cannot see its value

when connect charger on one side of this resistor is 20V on other side is pulling down to ground by Q4202

If anybody have schematic, share on schematics page
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Last edited by ktmmotocross; 07-03-2020 at 09:54 AM..
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Old 07-04-2020, 03:07 AM   #2
Duranitron
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Default Re: Lenovo E480 no sign of life

no free schematics available..all are paid.. anyone care enough to share their schematics..?
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Last edited by SMDFlea; 07-04-2020 at 05:01 AM..
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Old 07-04-2020, 06:39 AM   #3
ktmmotocross
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Default Re: Lenovo E480 no sign of life

we have some good guys like SMDflea that share this schematic

https://www.badcaps.net/forum/showthread.php?t=85795

Last edited by SMDFlea; 07-04-2020 at 06:54 AM..
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Old 07-04-2020, 07:04 AM   #4
ktmmotocross
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Default Re: Lenovo E480 no sign of life

in schematic i dont see any ID pin but in cable there is wire for it.

Anybody know how this USB-C charger work? i have new charger, why it dont give voltage?
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Old 07-04-2020, 09:10 AM   #5
SMDFlea
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Default Re: Lenovo E480 no sign of life

Google search "NM-B421 VSYSTEM2" ,you`ll find some posts on chinafix and elvikom. USB-C is still a mystery to me.
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Old 07-05-2020, 08:08 AM   #6
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Default Re: Lenovo E480 no sign of life

Quote:
Originally Posted by ktmmotocross View Post
we have some good guys like SMDflea that share this schematic

https://www.badcaps.net/forum/showthread.php?t=85795
thanks;;; salamatski...
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