The day before yesterday, a colleague sent me an ASUS laptop for repair. The fault turned off the power switch and there was no action. When plugged in, the current was high. When I disassembled the laptop, I found that the power connector was corroded.
Next, I cleaned it, and it was good to see that there were no
missing parts. It was still the same when it was powered on. The standby
current was high and there must be a short circuit.
This is not a big problem and it is easy to find. I took out
my magic tool and scanned it, and found that the 3.5V standby chip was hot and
hot when I touched it. I found the problem, reported it to my colleagues, and
then started working on it.
I was lucky enough to have the same board on
hand, but it was a higher version, the repair version was 2.0, and the material
board was 3.6. I was dumbfounded when I saw the chip, but the model was
different!
I found another ASUS board with a similar one on it, installed it
and powered it on, and then the chip felt hot again when I touched it, so I
quickly fixed the chip.
Check the standby 3V5V to ground value, which is about 300. I
disconnected the 35V isolation point and it was still hot after powering on.
Thinking of 35V linearity, I measured that the 3V to ground value was very low.
It should be pulled low at the back. I disconnected 3V.
The linear power on and standby is normal. Then the 3V linear is
burned and the EC temperature is too high. The 3V linear also goes to EC. I
disconnect the EC pin and the power on and standby is normal. It is an EC
problem. There is the same problem on the material board.
When it is turned on, the standby jumps from 0.03 to 0.06. , and
then contacted the seller. The standby chip he had just ordered had been
shipped, and there was no way to cancel it. He then asked him to send an EC,
which also came with a program.
I also tested the standby
conditions and found that RSMRST was only 1.6 and kept jumping back and forth.
It may be that the old EC was lowered, or the EC program was wrong, or the BIOS
was wrong.
When I thought of this, I looked for the BIOS and searched for at
least ten. I felt that this one was quite reliable. It's still the same after
downloading and swiping, so just wait for EC! When the courier arrived, I
opened it and installed the EC.
After powering on the bare board, I looked at the ammeter
intently. After powering on and off, I then powered on and ran to 0.6. The
machine would most likely turn on.First plug in
a USB keyboard and the light comes on OK.
The installation is completed perfectly.
Everything is normal when booting into the system. When I press the keyboard,
there is no action, and the touchpad has no action.
After continuing to troubleshoot, I found that
the keyboard can be used when entering the BIOS, but cannot be used when
entering the PE and system. Is it a BIOS flash problem? I changed back to
the original BIOS from yesterday.
I was desperate and asked if there was a program
problem in the EC. The first answer was that the EC was not soldered properly.
If it didn't work, just replace the EC. I removed the cleaning pad and put
it back in. After installing it, I didn’t add any soldering this time.
I took a look around and found that there were 3
pins that were weakly soldered, so I used a soldering iron to fix them.
If there is no other problem, I won’t re-solder it. Last time, I
re-soldered it after it was done. After powering on the system, I touched the
touchpad first and the mouse moved, and then the keyboard was fine.
Could it be that the problem was caused by not re-soldering it before
and then re-soldering it? problem, test other functions and everything is
normal, and the repair is completed.
Nice 👍 one man
ReplyDeleteThanks :)
Delete