Dell Inspiron 3521 Laptop - Motherboard shorting out power adapter

[googlemad]

The neighbours have given me their Dell Inspiron 3521 laptop to look at as it isn't powering on or charging.

 

I've found the issue, as soon as you plug in the power adapter the green light on it goes out - Luckily I also happen to own a Dell laptop so tried my power adapter as the first obvious step - same result (and their power adapter charges my laptop perfectly fine)

 

Tried taking the battery out etc, exact same so now I've dismantled the entire thing and the power jack seems to be OK as if I plug the lead in to that when disconnected from the motherboard the green light stays on, so looks like the motherboard is causing the issue somehow even after trying to power it with nothing at all connected (even tried removing the motherboard battery just in case)

 

Any tips - can it be repaired economically? Can't seem to find anywhere doing a motherboard replacement at a decent price for this model

[difinity]

It's usually a mosfet or cap(s) shorted or burnt causing the issue with the charger. The parts cost pence, the kit i use to replace quite a bit more.

You'll need a multimeter. Remove the motherboard and inspect it. If it's an LA-9104P I have the schematic for it.

[googlemad]

It is the LA-9104P but I managed to bugger it up by breaking the CMOS battery slot trying to get it back in! (Knew it was going too well...).

 

Ah well the motherboard was born in September 2012 so it has had a reasonable 5 years life, they've agreed to buy a new laptop now anyway so I'll just keep this one around and maybe come across a cheap motherboard one day

 

Funnily enough one has just come up on fleabay!

Edited August 11, 2017 by googlemad

[difinity]

It was already broken, a battery holder is easy to replace.

Have you any plans for the dead board ? happy to cover postage and chuck a few quid on top towards your replacement/their laptop if you haven't.

[difinity]

I had a Dell Inspiron 5520 with an identical issue of charger light going out today. Different motherboard number but identical markings and layout in parts to yours.

Mosfet PQ101 was shorted and Capacitor PC104.

Replaced both and the laptop charges and powers on fine. The price of the Mosfet was 23p and capacitor about 2p.