Hasee K650D-G4D2 notebook is not turn on for repair

Machine model: Hasee K650D-G4D2

Board No.: 6-71-W65D0-D02

Fault phenomenon: laptop no booting, press the start button no response,no booting repair into the system automatically shut down from time to time

Maintenance process: first check no booting fault.Dismantle the machine, measure the big VCC Inductor Diode value is normal with bare board, open Xinzhizao Soft drawing,Switch FPC block J_10 pin m for SW1_BTN ා should be high level normally. After pressing Switch, there will be a high and low current of change signal. Plug in and test that VCC is 0V.

Hasee K650D-G4D2 notebook is not turn on for repair Figure 1

Trace the source, u49 3 pin output M_BTN ා went through r705 t. o Switch, measured 3 pin VCC 19v, after r705, it was 0V, on-line measured r705 diode value OverLoad, the 10K resistance was replaced.

After measuring the resistance,VCC at both ends was 0V. I was puzzled that the front end of the resistor had 19v at the beginning. Why didn’t it all at once?Check u49’s 1 pin VCC 19v, 2 pin VCC is 0V, the front end of r704 resistor connected with 2 pin is 19v, and the rear end is not.

This resistor is a 0 ohm resistor in the physical board. It is estimated that the hot air is damaged when replacing the r705. Find one to replace it.Again, both ends of r705 have 19v VCC, and the red and black meter of Ohm gear poked J_10 pin switch of SW1 is powered on, and booting up is normal.

Hasee K650D-G4D2 notebook is not turn on for repair Figure2.

When Nand is attached to the bare board and tested by external display, the following automatic shutdown interface will appear after entering the system, ranging from 3-10 minutes or so.

Hasee K650D-G4D2 notebook is not turn on for repair Figure 3.

At first, I thought that u49 was bad, so I changed it to another one and turned it off automatically. Finally, I thought that other Shenzhou boards had been repaired before, because there was a Q5 small six pin on the display card temperature control signal, which caused the automatic shutdown.

Look for the temperature control signal of the video card on the drawing, as shown in the figure below. This board type is q25. I have searched for q25 for a long time with a magnifying glass.After checking the drawing q25 and EC’s 115, 116 pin, one pen was connected to 115 pin, and the other was on the suspected small six pin. Finally, the q25 was found between the graphics card and the CPU base.

Remove q25, 1 and 6 pin, 3 and 4 pin. After 30 minutes of test, the automatic shutdown did not appear, and the machine was repaired.