Acer 4736ZG plug-in VGA power failure maintenance

Acer 4736ZG plugged in VGA and lost power. It was found that VGA and screen were connected via PCIE bus, and four 470UF capacitors were replaced. This time, the screen was installed and plugged in VGA test, and the fault was fixed here.

Machine model: Acer 4736ZG-442G50Mn

Fault phenomenon: power failure of external VGA

Maintenance process: the customer’s description is that the VGA is plugged in and the external connection is powered off. So, after dismantling the machine, I found that the NEC on the back of the CPU had been changed by my family, which is a common fault of NEC capacitors.

Now that NEC has been changed, just skip this question first. Then, I checked on the forum how to repair this common fault. A big brother said that PU13 and two nodes in the lower right corner of the board number are easy to be soldered. So, I added soldering once. The first time I tested the VGA directly connected without the screen, I tested it for half an hour, thought it was ok, installed it, and then tested it again. The result was still power failure!

Acer 4736ZG plug-in VGA power failure maintenance Figure 1

Acer 4736ZG plug-in VGA power failure maintenance Figure 2

Open Xinzhizhao software to check the drawings, and find that VGA and screen are connected via PCIE bus. So, try some 1000UF/10V desktop capacitors, and as a result, there is no problem. It is estimated that it is not stable enough after being changed at home.

Acer 4736ZG plug-in VGA power failure maintenance Figure 3

There are five 330UF capacitors in the household. I changed four 470UF capacitors. This time, I installed the screen and plugged it in for VGA test. Half an hour later, the power went off (it was a few minutes before), and the motherboard temperature was found to be a little high. As a result, it was put on my notebook, so I found a cooling bracket to test it again. At present, there is no problem for one hour, and the fault is fixed here.