Dell E5550 No charge (charger unidentified)

[SMDFlea]

Re: Dell E5550 No charge (charger unidentified)

While you have PU1 desoldered measure the resistance to gnd on pin 1 and 6 as well,just to be sure theres no other problems

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

Excellent, so PU1 is defective 100%, take new measurements and reply.

-----> PL3 countinuity to PU1 pin3 with, and without charger????

No continuity with and without charger (haven't soldered the new PU1 yet)
Problem?

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

While you have PU1 desoldered measure the resistance to gnd on pin 1 and 6 as well,just to be sure theres no other problems

With PU1 desoldered, 1 and 6 have infinity resistance to ground

[Vesko356]

Re: Dell E5550 No charge (charger unidentified)

No continuity with and without charger (haven't soldered the new PU1 yet)
Problem?

Are you sure?
Yes it's a problem of course. With the charger connected there must be a continuity between PL3 and pin3.
So maybe something else is blown too. Check voltages (charger connected) on PQ2 (pin 1,2,3) and PO3 (pin 1,2,3), also check PR8, PR10, PR11, PR12 (impedance).

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

Are you sure?
Yes it's a problem of course. With the charger connected there must be a continuity between PL3 and pin3.
So maybe something else is blown too. Check voltages (charger connected) on PQ2 (pin 1,2,3) and PO3 (pin 1,2,3), also check PR8, PR10, PR11, PR12 (impedance).

PR8, PR10, PR11, PR12 are those around PQ2?

[Vesko356]

Re: Dell E5550 No charge (charger unidentified)

PR8, PR10, PR11, PR12 are those around PQ2?

Board view screenshot.

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

Board view screenshot.

Ok, i'm sorry but what is impedance? I don't understand in english.

[Vesko356]

Re: Dell E5550 No charge (charger unidentified)

Ok, i'm sorry but what is impedance? I don't understand in english.

Nominal value in Ohms for the resistor- for example PR8 is 2.2KOhm, PR10 is 100KOhm and so on.

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

Nominal value in Ohms for the resistor- for example PR8 is 2.2KOhm, PR10 is 100KOhm and so on.

So i must desolder them, ok, sending in a while

[Vesko356]

Re: Dell E5550 No charge (charger unidentified)

So i must desolder them, ok, sending in a while

No, no - just measure each resistor as is on the board, no need to desolder.

[SMDFlea]

Re: Dell E5550 No charge (charger unidentified)

With PU1 desoldered, 1 and 6 have infinity resistance to ground

Pin 1 goes to the dock DOCK_PSID, its always worth checking the resistance as the dock pins can get corroded or short after a liquid spill.
Pin 6 GPIO_PSID_SELECT and pin 4 PS_ID go to the EC,the resistance is ok so there shouldn`t be any problem with it.

If @ PR7 isn`t populated then there will be no continuity between PL3 and PU1 pin 3. All voltages and other measurements seem ok to me,i`d go ahead and repalce PU1 .You can follow @Vesko356`s advice though and check those parts.

.

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

Pin 1 goes to the dock DOCK_PSID, its always worth checking the resistance as the dock pins can get corroded or short after a liquid spill.
Pin 6 GPIO_PSID_SELECT and pin 4 PS_ID go to the EC,the resistance is ok so there shouldn`t be any problem with it.

If @ PR7 isn`t populated then there will be no continuity between PL3 and PU1 pin 3. All voltages and other measurements seem ok to me,i`d go ahead and repalce PU1 .You can follow @Vesko356`s advice though and check those parts.

.

Yes confirmed charging after replacement of PU1.
Thank you both guys, beers on me if you ever come to Greece )))

[SMDFlea]

Re: Dell E5550 No charge (charger unidentified)

Great ,now where did i leave my passport

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

Great ,now where did i leave my passport

Damn you need passport now to come here!
F***g brexit!

[Vesko356]

Re: Dell E5550 No charge (charger unidentified)

If @ PR7 isn`t populated then there will be no continuity between PL3 and PU1 pin 3. All voltages and other measurements seem ok to me,i`d go ahead and repalce PU1 .You can follow @Vesko356`s advice though and check those parts.

According to the schematics PQ2 is N-channel fet and is normally OFF, when the charger is connected it receives 5V (5V ALW in this case) at the gate and goes to ON, so the signal NB_PSID can be able to reach PU1 pin3, so maybe Andreasbest didn't measured something very correctly here, but that's not important anymore.
Battery is charging OK that is important, but I can't find my passport too

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

According to the schematics PQ2 is N-channel fet and is normally OFF, when the charger is connected it receives 5V (5V ALW in this case) at the gate and goes to ON, so the signal NB_PSID can be able to reach PU1 pin3, so maybe Andreasbest didn't measured something very correctly here, but that's not important anymore.
Battery is charging OK that is important, but I can't find my passport too

I was assembling the laptop but when i read this i disassemble it again (thankfully only some screws) to measure again.
I swear to God there is no continuity between PL3 and PU1 pin3, i tried my fathers multimeter too, absolutely no continuity!

[Vesko356]

Re: Dell E5550 No charge (charger unidentified)

I was assembling the laptop but when i read this i disassemble it again (thankfully only some screws) to measure again.
I swear to God there is no continuity between PL3 and PU1 pin3, i tried my fathers multimeter too, absolutely no continuity!

WITH the charger connected there must be a continuity between PL3 and PU1 pin3, no other way, just think if there is no continuity how the signal from the middle pin of the charger can reach to pin3 of the PU1.
So either you take measurements without connected and powered adapter, or the multimeter is not OK

[Andreasbest]

Re: Dell E5550 No charge (charger unidentified)

WITH the charger connected there must be a continuity between PL3 and PU1 pin3, no other way, just think if there is no continuity how the signal from the middle pin of the charger can reach to pin3 of the PU1.
So either you take measurements without connected and powered adapter, or the multimeter is not OK

Mystery, all good now

[Vesko356]

Re: Dell E5550 No charge (charger unidentified)

Mystery, all good now

[SMDFlea]

Re: Dell E5550 No charge (charger unidentified)

WITH the charger connected there must be a continuity between PL3 and PU1 pin3, no other way, just think if there is no continuity how the signal from the middle pin of the charger can reach to pin3 of the PU1.
So either you take measurements without connected and powered adapter, or the multimeter is not OK

Just to clear up the mystery,continuity should only be checked when the board is unpowered .See the attached picture,the board is an LA-9591P ,ive soldered wires to PQ2 pin 1 and 3, the board isn`t powered. PR7 isn`t populated and as theres no voltage at PQ2 pin 2 there`s no flow between D/S S/D and no continuity

With the board powered and PQ2 active then there will be continuity,you just can`t check it with a meter,you know its there though as it has voltage on pins 1 and 3.

Havn`t found my passport yet..

.