Latitude 3301 not charge battery

[dclass-pro]

Hi guys I have this dell that with the battery charged it turns on correctly, but if I connect the charger I get the charging symbol but it doesn't charge the battery.
I found the shorted charger PU4401 ISL9538h that had pins 14 and 15 shorted and I replaced it. but it still doesn't charge.
I noticed 2 things:
1) without the battery connected if I connect the power supply, on the SDA and SCL pins of the battery I have 0V I measured the resistance with ground and it is very high, if I connect the battery I have 3v on the 2 lines.
2) if I try to turn it on without the battery the notebook doesn't turn on.
I checked the mosfets but they seem good.
On PR4401 I have 19V and on ISL9538h pins I have this:
Pin 17=19V
Pin 18=5.1V
Pin 19=3.2V
Pin 20=0
Pin 21=0.8
Pin 22=0.8
Pin 23=0
Pin 24=3.2V

What can I check?

Schematic & boardview -> https://www.badcaps.net/forum/troubl...istron-18769-1

[mon2]

Pin 17=19V
Pin 18=5.1V
Pin 19=3.2V

Double check these values.

Pin 19 is ground.

Pin 17 & 18 are the battery current sense pins so each should be close in the measurements. Otherwise, this current loop is broken.

[dclass-pro]

my charger is a ISL9538h here is a demo photo of the pins

[mon2]

Pins 21 & 22 should not be low. Study the pull ups and pull up voltage.

[dclass-pro]

the problem is that they come from the KBC but the KBC is not powered because on pin 5 I read 0.9V instead of 3V.

[mon2]

Which schematic are you referencing? Is it the one from your first post?

Check the always on rails if the KBC is not being powered. Measure the resistance to ground of this power rail. Someone may be shorted.

[dclass-pro]

yes exactly the diagram is the one in the first post, if I measure the resistance to ground it is on megaohms and if I connect the battery I have 3 volts on both lines.
I can't understand why it doesn't generate the 3v to power the KBC

[mon2]

Check the dual diode @ D20.

Remove all power. Meter in diode mode. Red meter probe on pin # 1; black meter probe on pin # 3. Meter should conduct. Reverse the meter probes, the meter should block = OL.

Repeat with pins # 2 & # 3. Post all measurements.

[dclass-pro]

This is the schematic pag.25 I have, and on pin 3 of D2501 I have 3V but on the KBC I have no voltage
KBC is at page 24

[dclass-pro]

I noticed that between pin 1 and pin 7 I have about 20V
but between pin 1 and pin 4 PS_ID_R I have 0v
If I put black push on pin 4 and red tip on pin 7 I have 19v.
But is it correct?
I disconnected the charging connector and I have the same thing.

[Sephir0th]

What did you mean with Pin 14 and 15 were shorted? To each other or to GND?

Also show pictures of your job.

[dclass-pro]

they were shorted to ground and the problem was the ISL because I changed it and it was solved

[mon2]

This is appearing to be a text book PS_ID fault since pin #4 on the power adapter connector is @ 0v. Trace this back to the mosfet that will be in series with this PS_ID line. This 1-wire line is broken for the communication so the logic board assumes by default that the power adapter is too weak to power the board AND charge the battery. The logic board is very likely being throttled in speed AND the battery charging feature is disable. Your bios will also report this default power adapter detection.

[dclass-pro]

I didn't understand what to check, I noticed that on D4302 on pins 3 and 2 I find 0.6V

[mon2]

Post your exact schematic here. Unable to find anything like your posted schematic on page 25. Nothing comes up in searching for 'D2501'.

[dclass-pro]

this is at page 43

[mon2]

Flux and remove the esd diode on the ps_id pin on the power adapter. Test again the voltage on this pin. Should be ~3v here else the MOSFET is likely damaged.

[dclass-pro]

I removed the ESD dido but nothing changes, I also removed the Q4301 mosfet but on the PS_ID pin I always have 0V

[dclass-pro]

"Test again the voltage on this pin. Should be ~3v here else the MOSFET is likely damaged."
Between ground and PS_ID pin? have 0V

[mon2]

Test the voltage to ground on each pcb pad for Q4301. Q4301 needs to be present to pass through the 1-wire communication to the adapter. Otherwise, Q4301 needs to be bypassed but then the crowbar circuit created by Q4301 is no longer available. The purpose is that if there is a high enough voltage on this 1-wire PS_ID line, the Q4301 mosfet is triggered to prevent damage to the EC.