Battery not charging - Dell Inspiron 3593 FD155 LA-JO81P (REV 1.0) (A00)

[mon2]

See attached. The pins you just referenced are SMBUS signal lines. These same signals are mated with pull-up resistors @ RE8 and RE9.

Measure the voltage to ground on each side of these resistors to confirm if we indeed have the pull-up voltage or not.

If you have +3VALW_EC present at the RE8 and RE9 resistors then the EC should be powered. Confirm the RTC_CELL voltage as well.

[lawrenceptrini]

Hi,

If I'm correct, I measured the voltage to ground of the resistors in line with pins 8 & 9 of EC chip.
Got 3.3v on either side of both resistors. RTC_CELL voltage on pin 122 of EC is 3.079v

[mon2]

Measure the voltage to ground on pins 6 and also 7 on the battery connector. The voltage should be ~3v3 for each pin.

[lawrenceptrini]

Voltage on pins 6 & 7 of Battery connector is 3.3v for both with ac adapter only plugged in.

[mon2]

Check each of these voltages with only the battery. No power adapter.

[lawrenceptrini]

Voltages of pins 6 & 7 of battery connector with Battery only connected is 0.000v for both pins.

[mon2]

Check if you have +3VALW with only the battery.

[lawrenceptrini]

If I'm correct, I checked a few places like Q15 and UL2 for +3VALW, but got 0.000v with just the battery plugged in.

[mon2]

Carefully measure the voltage to ground of each pin on the charger IC at PUB01. Post the table o measurements along with their pin and function labels. Important ones include to check the VCC pin to confirm the charger IC is being powered when using only the battery. Others including PSYS are of interest.

[lawrenceptrini]

Hi, Thanks,
Will do....

[lawrenceptrini]

Measurements taken with Battery only plugged in.

PIN# LABEL VALUE

1 CSON 10.70
2 CSOP 10.70
3 FSET 0.000
4 QPCP 0.020
5 CMSRC 0.074
6 QPCN 0.012
7 ASGATE 0.068
8 VDDP 0.004
9 LGATE 0.010
10 PHASE 10.70
11 UGATE 10.26
12 BOOT 10.26
13 NTC 0.014
14 CSIN 0.022
15 CSIP 0.022
16 ACIN 0.000
17 DCIN 0.002
18 VDD 0.005
19 PROG 0.000
20 ACLIM 0.002
21 SDA 0.000
22 SCL 0.000
23 PROCHOT# 0.005
24 ACOK 0.003
25 BATGONE 0.002
26 CCLIM 0.012
27 BMON 0.002
28 COMP 0.012
29 AMON 0.013
30 PSYS 0.000
31 VBAT 10.70
32 BGATE 9.97

[mon2]

See a few issues:

17 DCIN 0.002
30 PSYS 0.000

Locate the dual diode @ PDB01. Measure the voltage to ground on each pin.

Locate the resistor at PRB35. Measure the voltage to ground on each pin of this resistor. Remove all power. Measure the resistance of the resistor @ PRB35 in ohms. This resistor should be ~100 ohms when measuring across pins 1 & 2. Respectively, the battery voltage should be present on pin # 2 (after this 100 ohm resistor).

[lawrenceptrini]

Voltage to ground on pins of Dual Diode PDB01: Pin 1=0.100, Pin2=0.010, Pin3=0.110.

[lawrenceptrini]

Still have to locate resistor PRB35, seems to be on the other side of the motherboard.
Will be away from pc for a short while.....

[lawrenceptrini]

Found resistor through continuity. I'm getting a beep only on one side.
Voltage to ground with Battery only plugged in is 10.55v on each side.
With all power removed the resistance across pins 1 and 2 is 101.8 ohms.

[mon2]

Then PSYS cannot be 0v. Confirm this measurement:

30 PSYS 0.000

[lawrenceptrini]

Hi,
I double checked PSYS, with Battery only: 0.000v, with adapter only: 0.000v, with both plugged in: 0.000v

[mcplslg123]

MEC SIO tends to have issue with dry soldering. Touch up all the pins with lot of flux and solder iron.

[mon2]

The charger IC is not being powered when using the battery only. See the voltage to ground on pin # 17 = 0v.

The voltage is fed through the dual common cathode diode PDB01 where BA_PWR should be the voltage feed from the battery and +19V_IN is the voltage from the power adapter. If either voltage source is present, the charger IC will be powered.

We know the power adapter leg is fine but battery side is not working.

Review the voltage to ground on each pin of:

PQB28
PQB29

To me, the pin # on the drawn schematic symbol is not correct. Does not match the datasheet for each of these transistors. Measure the voltage to ground and use the pin # they show in the schematic for a review.

What should be happening is that when the power adapter is absent and only the battery is the source, then BA_PWR should offer the battery voltage to power the charger IC.

[lawrenceptrini]

Ok, will do