Review if there is a coin cell battery on the board. If yes, test the voltage to ground of that battery. This battery may need to be replaced with a fresh one. Often, the ec is powered by the coin cell battery when the main power rail is off.
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Dear mon2,
Thank you for your help. There is no coin cell battery on this board.
Regards,
mkdjComment
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Remove all power. Meter in resistance mode. Measure the resistance to ground of this J5 trace for the EC power rail that is absent. We are testing to see if the rail is being shorted so the voltage is missing.Comment
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Dear mon2,
Value of resistance to ground is 7.5 kOhm. So there is no short to ground on the +3V power rail.
Regards,
mkdjComment
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I'm working on my sister's laptop: Asus VivoBook F510UA-AH51 - The motherboard died so I replaced it.
The original board was:
ASUS X510UNR REV 3.0 A
The replacement board is:
ASUS X510UNR REV 3.0 B (identical except B vs A - I couldn't find an A board anywhere. Visually they are identical.)
It boots right up on the replaced motherboard and everything works fine on the new motherboard - but it won't run off battery. When I disconnect the charger it immediately dies. When I plug it back in and reboot the system - it still shows the battery at... -
I have an Asus TUF machine that doesn't run off battery. Runs off charger ok, shows orange battery charging light and shows battery is at 96%. Battery voltage is less than 0.5v though. It had a short on the 20v rail from a dead cap. Pic attached. Removed cap and replaced a dc in mosfet. Machine now powers and runs fine.
I have also replaced all 3 battery mosfets with no change. The 1st battery mosfet has 20v going in. Pic attached.
Does it sound like a battery ic problem, it has bq2470. Not sure if I should replace that as well at this stage as I'd need to order one.
Thanks.... -
Hello everyone
I have been working on this laptop mentioned in the title, it initially had a shorted capacitor. After I replaced it, the thing started working again, but there is still another problem. The laptop was running off a charger, the battery was reporting 96% charge... but when I unplugged the charger, the laptop died. I've measured the battery voltage - 0V. I think it is locked. (Screenshot from batterymon, below).
I've ordered a new 3rd-party battery, but I think there's something wrong with it too - the laptop boots, but the battery isn't charging. Also,... -
Hi everyone,
I have been working on a no power issue with my personal ASUS gaming laptop. It went dead a few months ago.
Some history:
Since then, I've found a blown mosfet on the GPU line which I replaced. It started up without a battery, then when I added the battery back it wouldn't start up again.
As a result, there were some blown components around the BQ chip. (The BQ chip itself - BQ24780S, the low side battery mosfet (shorted), and a resistor -> all replaced)
Now, with a new battery the system will start up and run off... -
Hi,
I have an Asus GA401Q which only works from battery power. That suggests the board is mainly fine.
The battery status is 255%, also with a brand new battery.
The BQ24800 was replaced since it showed signs that it was part of the problem, but possibly the battery was flat at that moment.
If I insert the 19V adapter in the DC jack and measure the current sense resistor's voltage it fluctuates between 0V and 19.5V and the keyboard backlight flashes (probably because the battery is almost flat. It does the same when I run the laptop from battery).
There's a...
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