Dell E5550 Charget goes off when plugged (shortcircuit?)

[Andreasbest]

Hello!
Today i received a Dell E5550 with the symptom i descrive in top.
When i plug the charger to laptop, the led goes off and i must replug it in 220V mains to get it back on, then it goes off again when plugged on laptop etc.
Seems like a shortcircuit but i need some help
Thank you in advance!

(pictures of motherboard and schematic attached)

[Vesko356]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

First check five pointed in red rectangle capacitors for short. Also PQ4, but most probably some of those five caps is in short.

[Andreasbest]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

Thank you for reply, checking now

[Andreasbest]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

First check five pointed in red rectangle capacitors for short. Also PQ4, but most probably some of those five caps is in short.

Hello Vesko and thank you for your reply again.
The capacitor in photo was indeed short, do you know the value of it to replace it?
Thank you!

[Vesko356]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

Hello Vesko and thank you for your reply again.
The capacitor in photo was indeed short, do you know the value of it to replace it?
Thank you!

Don't worry will be fine like that, there is no need to replace it, but for the peace of mind you can replace the cap with the ceramic 10uF 0805 25V one.
And check PQ4 - it's a AON7401 P-Channel mosfet, often after a shorted capacitor in 19V power rail, there is a problem with it as well, so just check it too.

[Andreasbest]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

Don't worry will be fine like that, there is no need to replace it, but for the peace of mind you can replace the cap with the ceramic 10uF 0805 25V one.
And check PQ4 - it's a AON7401 P-Channel mosfet, often after a shorted capacitor in 19V power rail, there is a problem with it as well, so just check it too.

Yes indeed it's short too.
Must order some now.
You think the rest circuit will be ok?

[Vesko356]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

Yes indeed it's short too.
I have many 7408, can i use these?

No you can't 7408 is 18A, 7401 is 35A, so you must find 7401.

You think the rest circuit will be ok?

Yes, everything will be OK, just replace 7401 and the board is ready to go.

[dellxps15]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

remove pr701 and see wich side is shorted.

[Vesko356]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

remove pr701 and see wich side is shorted.

Short to ground is fixed (was found). Mosfet itself is shorted (drain source gate), removing pr701 doesn't change nothing. Read carefully

[dellxps15]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

ok so he removed pq4 and none of the 8 pin is shorted annymore.

[Andreasbest]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

Can't find 7401 in reasonable price in EU
Does any of you have one? I'll pay with Paypal.

[dellxps15]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

i see in spain 2.99+1.5 shipment. ofcourse if u buy them from digi or cina ull get more more cheaper, but only if u need more component.

[SMDFlea]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

https://www.ebay.com/itm/10pcs-74O1-...p/192683660203

Never had any problems with the seller,always good parts,no fakes.

[Andreasbest]

Re: Dell E5550 Charget goes off when plugged (shortcircuit?)

https://www.ebay.com/itm/10pcs-74O1-...p/192683660203

Never had any problems with the seller,always good parts,no fakes.

I know but it will take forever to arrive.
I'll buy from EU this time.