Re: hp spectre x360 dead - please help

Hi mon2, thank you for your reply !
=> this is the MOSFET I purchased : [URL="https://datasheetspdf.com/pdf-file/959833/ExcellianceMOS/EMB20N03V/1"]https://datasheetspdf.com/pdf-file/959833/ExcellianceMOS/EMB20N03V/1[/URL]
I just edited my previous post to say that it is now working
Again, transistors purchased from Aliexpress have to be double-checked.
Still I am not sure that the one I put in place is correct, but at least this is working.

Thank you very much for being active on this...

Re: hp spectre x360 dead - please help

Oh it seems that transistors from Aliexpress are quite unreliable.
The one I mounted on the board has no diode behaviour between source and drain. I tested others, some have short circuits, some have 0.5 V threshold.
Could you please advise on what should be a consistent diode behaviour for this kind of NMOS transistor ([URL="https://datasheetspdf.com/pdf-file/959833/ExcellianceMOS/EMB20N03V/1"]https://datasheetspdf.com/pdf-file/959833/ExcellianceMOS/EMB20N03V/1[/URL]) between :
- Source to drain
- Gate to...

Re: hp spectre x360 dead - please help

Dear mon2, dear all,

I received PQ1 and PQ8 from aliexpress and changed them
I think the voltages around BQ24715 are now much as expected, however the battery is still not charging
What is the most important is that now, ACDRV pin (PQ1 and PQ8 gates) shows 25.90 V which is what expected.
Also HIDRV is now 15.80 when battery and AC are connected.
Finally, on PQ1's drain, I measure the battery voltage instead of AC input voltage. Shouldn't PQ1 and PQ8 be both active when their gate is at 25.90 V ?...

Re: hp spectre x360 dead - please help

Hi !
First I would like to apologize for the loooong delay because I could not find any free time to investigate further
Also thank you very much for your answer !

I have completed the table with measurements without battery (only AC power cord plugged) :

[CODE]
PIN LABEL w/o AC w/ AC no BAT
1 ACN 10,91 19,64 19,65
2 ACP 10,91 19,64 19,65
3 CMSRC 0,042 18,36 18,38
4 ACDRV 0,039 20,46 20,49
5 ACOK 0 3,332 3,336
6 ACDET 0 2,847 2,85
7 IOUT 0 0...

Re: hp spectre x360 dead - please help

Short update : I have taken all BQ24715 pin voltages with or without AC power.
[B]The laptop is always off during these measurements[/B] :
[CODE]PIN LABEL w/o AC w/ AC
1 ACN 10,91 19,64
2 ACP 10,91 19,64
3 CMSRC 0,042 18,36
4 ACDRV 0,039 20,46
5 ACOK 0 3,332
6 ACDET 0 2,847
7 IOUT 0 0
8 SDA 3,12 3,12
9 SCL 3,12 3,12
10 CELL 0 3,73
11 nBATDRV 4,592 4,059
12 SRN 11,29 11,29
13 SRP 11,29 11,29
15 GND 0 0
15 LODRV 0 0
16...

Re: New Members - please post your introductions here

Hello, my name is Bertrand, french biomedical researcher, with basic electronic skills
I find this forum particularly amazing, I wonder how I didn't hear about it earlier !

Re: hp spectre x360 dead - please help

Hi everyone,
First of all many thanks for this amazing thread which helps me to understand the power management circuit of the x360 Spectre.
I've got mine since 2013 and it's surprising still well performing, except for a battery charging issue.
When powered using the AC cable the laptop is working, but the battery is not charging and its level slightly decreasing.

I opened the laptop and changed the battery (the original one was swollen)
Also I noticed that PR91 and one of the 22uF/25V capacitors...