Lenovo Z500 laptop has standby not trigger repair

Lenovo Z500 laptop has standby not trigger repair

Lenovo Z500 notebook standby does not trigger repair, check the switch JPWRB1 4-pin voltage is 1.13V is not correct, D26 2-pin resistor R642 end 3.3, end 1.131, this resistor has a problem. Directly remove this resistor a line to pull over, and then power on the test 4 pin voltage 3.3 has, boot trigger, troubleshooting, repair to this end.

[Machine model] Lenovo Z500 (15.6-inch)

[Motherboard version] LA-9063P 1.0 discrete graphics card

[Fault phenomenon] laptop has standby not trigger

[Fault Phenomenon

Received a Lenovo Z500 fault machine, fault description last year replaced the screen, and now can not be turned on. Got the machine found that the screen bezel B shell aging. Disassemble the machine, take off the battery, power on the test standby 0.001, press the switch on 0.000, it seems to have ground party voltage did not go up, not trigger.

Remove the motherboard, remove the motherboard external power cable to test the standby 3/5V normal.

Lenovo Z500 laptop has standby not trigger repair Figure 1

Check the switch JPWRB1 4-pin voltage is 1.13V is not correct, open the drawing to check the 4-pin voltage source, U74 small 6-pin this chip can be installed or not.

Lenovo Z500 laptop has standby not trigger repair Figure 2
U74 pin 3 is also 1.13 trace this ON/OFFBIN # find J11 this node, one end is 1.13V one end is 0V continue to trace this location source.

Lenovo Z500 laptop has standby not trigger repair Figure 3

Lenovo Z500 laptop has standby not trigger repair Figure 4

Drawing R701 this resistor is not installed regardless, check D26 this tube are no voltage, the result of D26 2 feet of the resistance R642 end 3.3, one end 1.131, it seems that this resistor has a problem. Directly remove this resistor a line to pull over, and then power on the test 4 feet of voltage 3.3 has, boot trigger, troubleshooting, the repair is over.

Lenovo Z500 lapop has standby not trigger repair Figure 5