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The typical input current for that op-amp is +/-10pA with the shown configuration.

You have an apparent unexplained 20uA which is 2 million times higher.

Possible explanations (more or less in order of my guess as to likelihood from your limited information):

• U1 pin 8 power supply connection missing (eg. not soldered) on op-amp (causing the op-amp to be powered at ~1.8V through the input protection network).

• Damaged op-amp

• Damaged or incorrect resistors

• Severe contamination of the PCB

Suggest a good visual inspection under a microscope or magnifier, and measure voltage on pin 8, and if that doesn't turn up something (and you don't mind butchering your PCB a bit) cut the trace to pin 3. If you do mind, then remove the IC.

Visual inspection should look at the solder joints, at the traces (for breaks or hairline shorts) and at the components (for mechanical damage such as a scratched resistor).

The typical input current for that op-amp is +/-10pA with the shown configuration.

You have an apparent unexplained 20uA which is 2 million times higher. Assuming your '5V' is actually exactly 5.00V, of course.

Possible explanations (more or less in order of my guess as to likelihood from your limited information):

• U1 pin 8 power supply connection missing (eg. not soldered) on op-amp (causing the op-amp to be powered at ~1.8V through the input protection network).

• Damaged op-amp

• Damaged or incorrect resistors

• Severe contamination of the PCB

Suggest a good visual inspection under a microscope or magnifier, and measure voltage on pin 8, and if that doesn't turn up something (and you don't mind butchering your PCB a bit) cut the trace to pin 3. If you do mind, then remove the IC.

Visual inspection should look at the solder joints, at the traces (for breaks or hairline shorts) and at the components (for mechanical damage such as a scratched resistor).

The typical input current for that op-amp is +/-10pA with the shown configuration.

You have an apparent unexplained 20uA which is 2 million times higher.

Possible explanations (more or less in order of my guess as to likelihood from your limited information):

• U1 pin 8 power supply connection missing (eg. not soldered) on op-amp

• Damaged op-amp

• Damaged or incorrect resistors

• Severe contamination of the PCB

Suggest a good visual inspection under a microscope or magnifier, and measure voltage on pin 8, and if that doesn't turn up something (and you don't mind butchering your PCB a bit) cut the trace to pin 3. If you do mind, then remove the IC.

Visual inspection should look at the solder joints, at the traces (for breaks or hairline shorts) and at the components (for mechanical damage such as a scratched resistor).

The typical input current for that op-amp is +/-10pA with the shown configuration.

You have an apparent unexplained 20uA which is 2 million times higher.

Possible explanations (more or less in order of my guess as to likelihood from your limited information):

• U1 pin 8 power supply connection missing (eg. not soldered) on op-amp (causing the op-amp to be powered at ~1.8V through the input protection network).

• Damaged op-amp

• Damaged or incorrect resistors

• Severe contamination of the PCB

Suggest a good visual inspection under a microscope or magnifier, and measure voltage on pin 8, and if that doesn't turn up something (and you don't mind butchering your PCB a bit) cut the trace to pin 3. If you do mind, then remove the IC.

Visual inspection should look at the solder joints, at the traces (for breaks or hairline shorts) and at the components (for mechanical damage such as a scratched resistor).

The typical input current for that op-amp is +/-10pA with the shown configuration.

You have an apparent unexplained 20uA which is 2 million times higher.

Possible explanations (more or less in order of my guess as to likelihood from your limited information):

• U1 pin 8 power supply connection missing (eg. not soldered) on op-amp

• Damaged op-amp

• Damaged or incorrect resistors

• Severe contamination of the PCB

Suggest a good visual inspection under a microscope or magnifier, and measure voltage on pin 8, and if that doesn't turn up something (and you don't mind butchering your PCB a bit) cut the trace to pin 3. If you do mind, then remove the IC.

Visual inspection should look at the solder joints, at the traces (for breaks) and at the components (for mechanical damage).

The typical input current for that op-amp is +/-10pA with the shown configuration.

You have an apparent unexplained 20uA which is 2 million times higher.

Possible explanations (more or less in order of my guess as to likelihood from your limited information):

• U1 pin 8 power supply connection missing (eg. not soldered) on op-amp

• Damaged op-amp

• Damaged or incorrect resistors

• Severe contamination of the PCB

Suggest a good visual inspection under a microscope or magnifier, and measure voltage on pin 8, and if that doesn't turn up something (and you don't mind butchering your PCB a bit) cut the trace to pin 3. If you do mind, then remove the IC.

Visual inspection should look at the solder joints, at the traces (for breaks or hairline shorts) and at the components (for mechanical damage such as a scratched resistor).