Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

[BalkanBoy]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Is it PU701, PU801 or one of the mosfets nerby coming from B+?

This is not tipical fault as you said and my opinion is that this riddle isn't for freshers. You find it very simple now when it's solved, but without board in front of you it isn't simple at all...

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Thanks@balkanboy, atleast you are trying and thats encouraging and it shows you want to learn.

NO, PU701/PU801 or any mosfets connected to these ic are not bad.

I know its difficult to suggest without having board in front of you but thats exactly what we do on this forum. Lot many members have benefitted from those advises.

I find this case simple yet tricky and it took me less 10 mins to solve it-so definitely its not that complicated.

See a mb doesnt post based on voltage on coils alone-there are lot many things involved. Voltage on coils is just a prrof of those rails rising.

[BalkanBoy]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Maybe something with power saving mode when running on battery? I assume all signals from EC are good?

[Stevedb]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Is not double diode that failed. If it not powers up on battery

[usyusy]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

If there is no fault at voltage level, it seems to be on some data/communication level or bus

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Is not double diode that failed. If it not powers up on battery

No, its fine

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Maybe something with power saving mode when running on battery? I assume all signals from EC are good?

Yes all EC signals are good and nothing wrong with power saving mode.

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

If there is no fault at voltage level, it seems to be on some data/communication level or bus

How do you assume there is no fault on voltage levels?? If the voltage on coils are same on adapter/battery, does that indicate no fault on voltage level? there is lot more involved then coils volatge. However, there is no communication glitch.

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Ok here is a clue. It has something to do with cpu requirements.

[usyusy]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Ok here is a clue. It has something to do with cpu requirements.

IMVP_PWRGD generating?
Core IC pin 4,6,7 has voltage ?
+1.05V_RUN_VTT Ok ?

core section capacitors ok (i think some 4 may be are there)

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

IMVP_PWRGD generating?
Core IC pin 4,6,7 has voltage ?
+1.05V_RUN_VTT Ok ?

core section capacitors ok (i think some 4 may be are there)

Nothing wrong here.

[lapfix]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

If i m understanding the issue :

It works perfectly fine with adapter...but shut off when only connected with battery !

All your measurements are presents.

What's the consumption when on with charger and when charger is disconnected !



My confusion is about your title and your discription :

Title = Dell Inspiron 5520 LA-8241P Not working with battery....so for me the lap consumption is 0.001 amp

Discription = with battery only It triggers but nothing on screen...so for me the lap consumption is more than 0.800 amp

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Read the post carefully and there should not be any confusion. How i can measure consumption when adapter is disconnected?? Atleast i dont know. Yes it works like a charm with adapter only+adapter along with battery. Wants to turn on with the battery alone but switches off in few seconds without display. Yes voltage on all coils are same with all the 3 power options. One need to think beyond coil voltages. I've given a clue already. Its related to cpu power.

I started this case study for freshers only and its a tough task for them frankly.Even experienced members may struggle to solve it. The whole idea is to improve problem solving skills.

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

I'll share the solution on coming monday but wants more thoughts on how to solve it.

[juergenb]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Is there any current sense resistor for the battery faulty?

I could think a about a faulty one, if the current is to high, the laptop could shut down.

[usyusy]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Is there any current sense resistor for the battery faulty?

I could think a about a faulty one, if the current is to high, the laptop could shut down.

Originally Posted by mcplslg123 View Post
Ok here is a clue. It has something to do with cpu requirements.

[Til]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Bios settings? Old post ,but no answer. I'm curious.

[mcplslg123]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Bios settings is not the reason. No solution was provided as hardly any response from members to learn. This was part of a paid case study from us.

[Udemzy]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Which means it doesn't display when on battery is connected.
Like you said ,the clue in on the core section, then it could be that the required current is not really generated with the battery.

Changing the Polaris Caps could be a possible fix or one the upper drain MOSFET is faulty.

I don't think it's a NTC/PTC issue.

[Sephir0th]

Re: Dell Inspiron 5520 LA-8241P Not working with battery(For freshers only)

Hey hey hey, I never came across this thread before...

Am I allowed to try?