Dell m5110 power issue

[bluestone]

I have done a lot of troubleshooting on this particular board but it is always getting me confused so I need help. The problem is that no power at all immediately you plug in the charger TPS51123 start to get hot. I have replaced it with a new one still same.
this is some readings I did on the Tps51123 when charger is plugged in
pin16 = vin=19.1v
Pin8 = vreg3=0.983v
pin17=vreg5=5.1v
These pins also short to ground immediately charger is plugged in pin7=v02, pin24=v01, pin12=drvl2, and pin21=drvl1.
I need help

[samanthban]

Re: Dell m5110 power issue

I failed too, with this situation in dell 3521 .once charger is plugged in power button short to ground after some time that will disappear~

[bluestone]

Re: Dell m5110 power issue

I think there should be a way out

[lukkil]

Re: Dell m5110 power issue

did u solve the problem?
cheers

[ktmmotocross]

Re: Dell m5110 power issue

find why is Vreg3 pulled low. maybe kbc is bad but u must find what pulling down 3D3V_AUX_S5. i see there are many things that could do it, like Q2703, Q2701 ...

go one after another. if u cannot measure bad thing just go one by one and remove ics that could do that

also that shorts on 3v and 5v sides must be rid off. check all 4 mosfets