820-01958-A: completely dead: no voltage no amp

phantom

Member
hi, please help! i have

820-01958​

dead: no liquid spill or damage.

amp meter stay completely off in both ports...

i have 4ohm resistence on
PP20V_USBC_X_VBUS and PP20V_USBC_T_VBUS

If i go on those line with power supply with 1v 1amp, it goes directly to 0,27v 1amp in both lines but i can't see anything hot
 
Last edited:

2informaticos

Administrator
Staff member
"1v 1amp"
???

If you have pure short, the board tries to sink way more current.
PSU will NOT inject anything, if you set 1A limit.
I ALWAYS said on the forum: set amp limit to MAX on PSU first.

D3300/20 are the first suspects; or D3302/22, if soldered.
If the CD3217 chips are bad, you should find bad diode mode readings on several lines.
 

phantom

Member
I mean that I have set power supply with 1v and amp limit to 1amp

And as soon as i touch the line, motherboard sink 1amp

I’ve removed both cd3217 but short persist in both lines
 

2informaticos

Administrator
Staff member
Try to get them from scrap boards.
Machine will work without them; of course, no overvoltage protection anymore.
This kind of failure is caused by bad/fake charger.

"motherboard sink 1amp"
And dropped to 0.25V, becuase entered in protection mode...
 
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