TOSHIBA C50-B-14F works but no charging

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

Hello
I won't be able to work on the pc for a long time, so I wanted to thank you for your help.
I will come back to you to inform you of the progress of my investigations.

[mon2]

Re: TOSHIBA C50-B-14F works but no charging

Hello
After this long time of absence, I come back to give you news of my PC.
So I received the 2 mofsets PQB03(AON6414AL) and PQB04(SI7164ADN) that I welded to replace those already in place, but this did not solve my problem.

In desperation I decided to buy a new battery that I plugged in in the early afternoon and unfortunately it is recognized with a charge of 55% but is not recharged by the PC.
Finally I replaced once again the charging chip BQ24735 and the 2 charging mofsets PQB01 and PQB02, but it was completely useless since the battery charge still does not work

When you plug in the adapter AND the battery, does Windows show the battery symbol ? Does the battery graphic show that it is charging ?

[mon2]

Re: TOSHIBA C50-B-14F works but no charging

1) Remove mosfet @ PQB07 (battery mosfet) and power up again with the battery and adapter. Any difference?

2) Measure the voltage to ground of

SRP (pin #13)
SRN (pin #12)

of the charger IC - measure at the charger IC pins.

Red meter probe @ pin to test; black meter probe to ground. Meter in DC 20v or higher scale. These pins are the current feedback pins for the battery voltage. The voltage on each pin should be close to each other in value and to the battery charge voltage.

The charger IC measures the difference in voltage (ie. voltage drop) from the start to exit of the current sense resistor (SRP to SRN) to determine how much current is being consumed by the load = battery being charged.

3) Be sure that the replacement charger IC is working - check

REGN ; should be ~6 volts
ACOK ; should be the pull-up voltage of ~3 volts
ACDRV ; should be ~25v to enable the DCin mosfets

EC_SMB_DA1
EC_SMB_CK1

Post each measurement.

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

Ok, I'll look at this tomorrow.

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

here's what Windows shows on battery.

The 1st time I plugged in the battery:

[mon2]

Re: TOSHIBA C50-B-14F works but no charging

For pic # 1, only the battery was used to power up? (no adapter?)

For the pic # 2, did you plug in the power adapter ?

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

yes

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

here are the voltages on each pin of BQ24735, PC off, with the battery plugged in and the AC plugged in.

1: 19.2v
2: 19.2v
3: 19.2v
4: 25v
5: 3.3v
6: 2.5v
7: 0.5v
8: 1.4v
9: 3.3v
10: 0.8v
11: 15.5v
12: 15.5v
13: 15.5v
14: 0v
15: 0v
16: 6v
17: 19.8v
18: 19.7v
19: 15.4v
20: 18.8v
After taking these measurements, I removed the PBQ07 mofset and the charge is still not done.
In the manual they say that if the light "input adapter / battery" is orange, it is that the battery is charging and my light is orange ???

[mon2]

Re: TOSHIBA C50-B-14F works but no charging

Measure the voltage to ground again for pins 8 and 9 on the charger IC.

Pin #8 = SDA communication pin appears to be too low of a voltage and may be stuck.

Locate also the battery connector. The same SDA and SCL lines will be present there for communication with the BMS (battery management system) inside each battery pack.

Measure the voltage to ground of these pins at the battery connector.

Post all measurements.

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

Voltages are ok with 3.2v
You had offered me to reflash the bios, but I can not find it on the net, but I found a Toshiba "Gas Station" app that should have offered me to download the latest bios, but the app does not offer me anything.
In addition this app has a battery test that I did and everything seems normal, except this message see photo.
It may be necessary to wait some time for the load to be visible in Windows.

[mon2]

Re: TOSHIBA C50-B-14F works but no charging

Measure the voltage to ground of pin 15 and also pin 18 on the charger IC.

Each is driving the gate pin of the local mosfet.

Pin 15 is 0 volts?

What are the voltage markings of your battery pack?

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

15 : 0v
18: 19.7 V
and 14.8V battery

[mon2]

Re: TOSHIBA C50-B-14F works but no charging

What is the voltage to ground of pin # 11 (BATDRV) on the charger IC

a) with NO adapter but battery is attached ?

b) with adapter and battery attached ?

Update - see attached.

Interested in the review of ILIM pin.

After these measurements - power down - remove resistor PRB22 off the logic board and test again.

ILIM is a definition of the MAX current the charger will apply for the charge current. It will select the lower of 2 values - internal or defined by the external voltage on this pin.

From my calculations, if +3VALW is ~3v, the voltage @ ILIM should be ~0v72.

If PRB22 is removed, the external voltage on ILIM will not be used for the MAX charge current.

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

Hello
I raised the voltage on pin 10 to 1v2 by putting another resistor of 300K in parallel on PRB21 it was simpler than desoldering it.
Pc off the consumption has not changed so I guess the charge is not done.

otherwise for pin 11 measurements:
with AC without BAT: 3.14v
with AC with BAT: 15.5v
without AC with BAT: 21.5v

I tell myself that after changing the charging chip and all the mofset it should have worked again, maybe once again I have a battery that does not work, so I think I stop there before damaging the motherboard.
I was thinking of adding a battery holder, the location being provided I will just have to add one or two missing components on the board and so I will have at least the date and time saved when the AC will be unplugged.
What do you think?

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

I believe that I will not be able to get a refund for the battery because I just realized that the battery packaging had a seal and amazon will refuse to take it back after opening.

[mon2]

Re: TOSHIBA C50-B-14F works but no charging

Reflash the EC at UB1 (KB9012QF). It is the SMBUS master and communicates with the battery and charger IC. Perhaps the 8051 based firmware has been corrupted.

Using a low cost bus analyzer tool, you can monitor the SMBUS traffic on the shared smbus lines.

With an Arduino or better yet, the EV2400 tool, you can extract / modify the vitals of the battery pack.

Wait on other comments on this case.

[mon2]

Re: TOSHIBA C50-B-14F works but no charging

Tell amazon the battery does not charge in the target laptop.

[telenaze]

Re: TOSHIBA C50-B-14F works but no charging

Hello
I was able to get the battery refunded.
I will keep you informed if I can change my problem.
Thanks again for the help.