820-4924 no green light on charger with battery plugged in

Gannons3

New member
i have an 820-4924 that wont get a green light while the battery is plugged in, if you unplug the battery and plug in the charger you get a green light computer can boot ect, then if you plug the battery in while the charger is plugged in it will charge normally greenlight stays, but when the batterys plugged in and the charger is plugged in after, it will not give a green light
 

dukefawks

Administrator
3V42 still present with battery connected? Do an SMC reset on the keyboard with battery plugged in, does the green light appear after that?
 

Gannons3

New member
computer recognizes and runs off the battery, just no green light from the charger, like i said if i have the charger plugged in and its running i can plug the battery in and itll charge then but after the charger is unplugged and then replugged in it will no longer charge or give a light
 

larossmann

Administrator
Staff member
This happens to me when the transistor creating PPBUS_G3H gets stuck and sends 16v to PPBUS_G3H. the system will still work but it disables the charger when battery is plugged in so 16v doesn't go to the battery and smoke it.
 

larossmann

Administrator
Staff member
Nvm, that isn't it then.

What happened to this machine originally to cause this? Water, bad DIY repair attempt, drop?
 

Gannons3

New member
water, they took it somewhere else first, it looks like they cleaned the board somehow but the water detection circles are white besides by the lcd connector and i can see a little left over corrosion under the board by the backlight data line caps, this machine had no backlight which i repaired, the traces were fried on the lcd data lines
 

Gannons3

New member
every once in a while the charger will not give a green light even when the battery is out, it will like flash green then go off then after a couple seconds itll come green then flash off again then it will randomly work fine, possibly dying isl?
 

smiba

New member
Really not recommended to do that, its there for a reason. Shorting smc_bc_ok to pp3v42 might damage the SMC and will also possibly start the SMC before the power is actually stable which can cause weird issues.

Is the charger a known good charger? Might be pulling too much because it tries to charge the battery and boot the system, but unlikely the issue. Also check out the U7100 area, if all passive components measure alright you can try to replace it. Otherwise might be SMC related, not sure.
 
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