Calibration failure EDU09

I now have -5.2V at IC2 pin 4. I have not changed anything so confused.

Hi

One other point is that I am using a USB 3 connection.

Does this influence the board?

At present I have all the correct voltages at points A through to F and at IC2 pin 4.

Calibration results:

CH1 offset at 2V/div : 179 FAIL
Rounds : 51
CH1 offset at 1V/div : 56 FAIL
Rounds : 51
CH1 Y-position low, CH1_DAC1 0 83
Rounds : 51
CH1 Y-position mid, CH1_DAC0 0 179
Rounds : 51
CH1 Y-position high, CH1_DAC2 0 255
Rounds : 32

The USB cable can be connected to USB 3 socket of the PC without any problem.
There may be some bad soldering on the board or solder bridge …

Well bad soldering is sure a possibility.-)

Please check IC1 orientation.

Notch is facing the capacitor bank.

Calibration results:

CH1 offset at 2V/div : 77 FAIL
Rounds : 51
CH1 offset at 1V/div : -46 OK
Rounds : 51
CH1 Y-position low, CH1_DAC1 255 0
Rounds : 33
CH1 Y-position mid, CH1_DAC0 255 77
Rounds : 51
CH1 Y-position high, CH1_DAC2 255 173
Rounds : 51

This result may indicate that there is no +5V on pin 8 of IC2.

IC1 orientation seems to be OK.

+5.027V is on PIN 8 of IC2

alibration results:

CH1 offset at 2V/div : 77 FAIL
Rounds : 51
CH1 offset at 1V/div : -46 OK
Rounds : 51
CH1 Y-position low, CH1_DAC1 255 0
Rounds : 33
CH1 Y-position mid, CH1_DAC0 255 77
Rounds : 51
CH1 Y-position high, CH1_DAC2 255 173
Rounds : 51

OK - Please check the voltage on pin 1 of IC2.
There should be about 1.6V.

Here are the voltages measured on all IC2 pins:
These voltages are measured when the USB cable is connected but the PC software EDU09 is not running.
1: 1.76V
2: 0V
3: 0V
4: -5.2V
5: 0V
6: 0V
7: -1.65V
8: 5.0V

On IC1 pins the voltages should be:
1: 0V
2: 0V
3: 0V
4: 0V
5: 0V
6: 0V
7: -5.2V
8: 0V
9: 0V
10: 0V
11: 0V
12: 0V
13: 0V
14: 0V
15: 0V
16: 5V

These voltages are measured when the PC software EDU09 is running.
Here are the voltages measured on all IC2 pins:
1: 1.65V
2: 0V
3: 0V
4: -5.2V
5: 0V
6: 0V
7: -1.65V
8: 5.0V

On IC1 pins the voltages should be:
1: 0V
2: 0V
3: 0V
4: 0V
5: 0V
6: 0V
7: -5.2V
8: 0V
9: 3.3V
10: 0V
11: 0V
12: 0V
13: 0V
14: 0V
15: 0V
16: 5V

Here are the IC2 VOLTAGES PIN 1 =4.7V
PIN 2 =-0.12V
PIN 3 =0V,
PIN 4 = -5.2V
PIN 5 = 0V DIRECTLY OPPOSITE 4,
PIN 6 = 4.1V,
PIN 7 =2V,
PIN 8 =5.02V.

ok sorry will re do with program off.

Here are the voltages measured on all IC2 pins:
1: 2.2V
2: 0V
3: 0V
4: -5.2V
5: 0V
6: 0V
7: -2.13V
8: 5.0V

The voltages are measured when the USB cable is connected but the PC software EDU09 is not running.

On IC1 pins the voltages should be:
1: 0V
2: 0V
3: 0V
4: 0V
5: 0V
6: 0V
7: -5.2V
8: 0V
9: 3.3V
10: 0V
11: 0V
12: 0V
13: 0V
14: 0V
15: 0V
16: 5V

Hi Sorry this is taking time but as you can see my results on IC1 are same as you except IC2.

I also noticed that when the sw was running that the relay does work as I can hear it clicking when selecting ac to dc.

Bingo checked the solder joints on IC2 and one was not soldered. Checked with magnifying glass. Thank you very much for your support.

Explains the varied results.

No problem. Glad to be of assistance. Enjoy your EDU09 :slightly_smiling_face: