Laptop Model: Acer LA-B162
Board Number:LA-B162
Fault : The Laptop is not powered on and the standby current cannot be seen.
Maintenance Process:
When I turned on the power, there was no response, no power, and I
quickly took it apart. The board was new and had not been repaired.
Since there is no power and no standby current, the first thing that
comes to mind is that the common point is short-circuited, because many of the
current new machines have short-circuited common points, and the ammeter has no
response at all, and some have prompts.
As expected, the value of a dozen common points is unexpected, and the
machine immediately burns up. Show the original shape (if the filter capacitor
of the upper tube is short-circuited, it will be killed directly).
This capacitor is short-circuited. There is only one on the board.
After it is removed, the value is restored. When the power is turned on, the
ammeter will see the current coming out and then disappear. It seems normal.
After connecting the switch and pressing it, it lights up perfectly. However,
after the installation, I found that the power is 0.53. Do not move.
After dismantling the bare board, there was no
problem. Could it be caused by peripherals? Optical drive, keyboard,
touchpad, or USB tablet? Now that you have an idea, let’s do it! Looking
at it one by one, it turned out that after all the downloads were completed, it
was still possible to click. Finally, after installing the hard disk, the
problem surfaced and it was caused by the hard disk. The same thing
happens when trying another hard drive.
I checked the
hard drive condition myself and found that the 5V power supply fluctuated a
bit, but it was not a current that would stop the computer from turning on. 4.9-5.2
fluctuated like this, and the data line values were all normal. I checked
them one by one and found no problems. At that time, I felt that the fluctuation
of 5V was not enough, so I directly soldered it to convert it, that is, this.
Nowadays, many chips like this control 35V to the rear, and the result
has not changed. The same goes for flashing the BIOS. I have been going back
and forth like this for a long time.
I have checked everything that needs to be checked. If there is no solution, the target starts to release the bridge itself. The result After installing the BGA, I did not replace it and soldered it, but the result was the same.
I found the drawing and looked at it. Is it possible that it was
caused by removing the capacitor on B+? I didn't think much and added another
one.
The result is really surprising. After removing the added capacitor, it
returned to 0.53 of the hard disk. Now I removed the inductor and connected it
directly, and the result is that the computer can be turned on.
The hard drive was also normal. I thought it was really caused by the
inductor at first, so I replaced it with an inductor, but it turned out that it
was not.
It was the same thing if I didn't replenish the capacitor after
replacing it. The hard drive wouldn't turn on, and now I only have the chip
without replacing it. I just replaced it and just replenished it. After
returning the capacitor, the computer turned on. I think it was caused by the
B+ filter capacitor.
Happy Repairing !!
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