Re: HP EliteBook 840 G2 power problem
Like this, and in this end:...
bollin
Senior Member
Last Activity: 11-09-2023, 10:01 AM
Joined: 03-07-2013
Location: Vaasa
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Re: HP EliteBook 840 G2 power problem
I mean that I used a pair of pliers to make the dc jack connector on the motherboard tighter, and that way improve the connection.Leave a comment:
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Re: HP EliteBook 840 G2 power problem
SOLVED! The problem was the DC Jack, or rather a poor connection to the center pin. After I read about someone who had the same problem and solved it by crimping the DC jack I measured and found that it did not connect that well. I took a pair of pliers and crimped the base of the DC jack, after that it worked like new!Leave a comment:
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Re: HP EliteBook 840 G2 power problem
New info: Limit_signal is at 0.16v, should be at 2.7 volts... that's why it doesn't recognize any chargers...Leave a comment:
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Re: HP EliteBook 840 G2 power problem
New turn: after a reinstall of windows due to a unrelated problem, some HP software is now telling me that the smart adapter is not working and that I should replace it. It does however work on my wifes 840 g2, and I get the same message when using her charger on my computer. Back to square 1...Leave a comment:
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Re: HP EliteBook 840 G2 power problem
Shouldn't acdrv be cmsrc + 6 volts for q6011 to open? But cmsrc is only 0.11 volts with battery and charger connected, but 19.5 volts without battery. I will recheck values tonigjt....Leave a comment:
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Re: HP EliteBook 840 G2 power problem
HIDRV is 11.4 volts with both battery only and battery + ac. On ac only it is at 1.5 volt rising to 2 volts at the same rate as the ticking.Leave a comment:
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Re: HP EliteBook 840 G2 power problem
It was, yes. PVBATis 11.4 volts with battery only, 19.4 volts on ac but dropping to 17 volts at the same rate the ticking is heard. PVPACK is 11.4 volts battery only and 1.5 volts on ac only and rising to 2 volts at the same rate the ticking is heard. Q6000 and q6001 are confirmed good, and tgat makes me believe it is a faulty u6000...Leave a comment:
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Re: HP EliteBook 840 G2 power problem
With or without battery connected?...Leave a comment:
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Re: HP EliteBook 840 G2 power problem
There was an official update, so I tested it. The charger was recognized by the bios update program, it would not work otherwise. Now nothing happens. I will measure resistance as soon as I get home from work.Leave a comment:
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Re: HP EliteBook 840 G2 power problem
Well, i tried updating bios and now it doesn't recognize the charger at all.Leave a comment:
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Re: HP EliteBook 840 G2 power problem
Checked both N-channel FETs, they are both ok.Leave a comment:
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Re: HP EliteBook 840 G2 power problem
Also, ohms at L6000 are about 136 kohmsLeave a comment:
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Re: HP EliteBook 840 G2 power problem
Here are the voltages on u6000
U6000 with only AC Adapter:
Pin1: 19.4- 17v
2: 19.4- 17v
3: 19.4-17v
4: 25.3-22.4v
5: 0v - 1.35v
6: 2.5v
7: 0v
8: 3.2-3.3v
9: 3.2v
10: 3.2v
11: 0v
12: 2v-1.3v
13: 2v-1.35v
14: 0v
15: 0v
16: 5.92v-5.85v
17: 5.76v-5.7v
18: 2v-1.35v
19: 2v-1.35v
20: 19.4v-17v
Battery connector:
1: 1.6v-1.1v
2: -"-
3: 3.3v
4: 3.3v
5: 0v...Leave a comment:
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Re: HP EliteBook 840 G2 power problem
I know, my probes are not the best ones so I have to find the resistors that are connected to those pins ( they are not marked) and measure there, and I have not finished taking those measures yet, I will post as soon as I get them...Leave a comment:
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Re: HP EliteBook 840 G2 power problem
Yes, but I believe bios is not the problem. Did some probing this morning and without battery PVPACK is fluctuating between 1.35 - 2 volts, as is q6000 pin 4, but they are not shorted.Leave a comment:
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Re: HP EliteBook 840 G2 power problem
No, I have already updated bios but no difference. However, the bios update software requires AC adapter to be plugged in and it did detect The AC adapter when Windows does not detect it.Leave a comment:
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Re: HP EliteBook 840 G2 power problem
Or possibly q6000 pin 4?Leave a comment:
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Re: HP EliteBook 840 G2 power problem
Now it has happened again and I don't know what is broken. With battery and adapter connected it says in Windows that it runs on battery only, but it isn't draining it, the charge stays on the same percentage. If I pull the adapter it starts to drain the battery. If I pull the battery it lights up and runs on ac power only. My wife has the same laptop from work, so I can use her computer to charge my battery. It charges in her computer but not mine. Both her adapter and mine works on her computer, and that includes charging the batteries....Leave a comment:
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HP EliteBook 840 G2 power problem
I have this weird problem that it sometimes doesn´t detect AC adapter.
The last time it went so far that I had to open it up (because I thought DC jack was broken) but it was fine. LIMIT_SIGNAL was 0v but after applying 3v it started working ok again (2.75v). I tried with 3 different known working adapters so I know that wasn´t the problem.
Where do I start searching if it happens again?...Last edited by bollin; 09-17-2018, 10:32 AM.
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