Power Up Test 2 is failed. V3 is not zero.

[lozd]

Power Up Test 1 is passed.
All steps above V3 measurement in Test 2 are completed. LCD and controls are working fine.
AV+ = 5.51V
V- = -5.51V
AV- = -5.40V
VA = 5.51V

V2 = 0V
V3 = -1.57V
V4 = -3.32
According to assembly guide U1 chip on my board may have been damaged.
What can you advise in this case? Will it help buying and resoldering a TL082 chip?

[jye1]

Please first verify the voltage at V3 is from U1 or U2. To do this change SW3 to X5 position and see if V3 remains unchanged. If it does then the voltage is from U1. In this case check the power supply pins of U1 for correct voltages (pin4 = AV-, pin8 = AV+). Check soldering of U1. If all these are good and V2 is 0 (check V2 at the U1 pin3) we can conclude U1 is broken.

For replacement please contact JYETech at jyetech@163.com.