Test signal output copper pad broken

[Maxim]

Hi everybody!
I buy DSO 068 Kit and solder all parts. Tests pass successfully. I solder piece of wire between test signal output and scope input and start adjust compensation capacitors. After calibrating and try desolder the piece of wire but copper pad deglued from board and then broke (disconnect). Can you show me another point on main board where I can connect to test signal output. If there are more than one point please show all - I choose more suitable for soldering.
Thank you in advance.

[Gary]

Check at discrete resistor R31. Select the side that connects to surface mounted capacitor C31. That should work well. Good Luck!!

Gary

[Maxim]

I touch probe tip with a finger and get main signal as shown on picture. Then I touch probe tip to R31 (both sides) - no signal at all. (Ground of test signal not connected.)

I write small sketch for arduino ( tone(8, 10000); ). Buzzer produce sound. Oscilloscope - no signal.

[jye1]

Did you probe pin14 of U5? It's where the test signal comes from. Was the keypad working when you did the probe?

[Maxim]

Keypad working independly (I not understand "when you probe").
X5 1V DC - very low trace on pin 14.

[jye1]

The test signal comes form the keypad controller. That's why I asked. The test signal is 3.3V in amplitude. If you probe it with "X5 1V" (i.e. 5V/div) setting it should look less than one division. If that was what you saw that means the chip did produce test signal. There is maybe open in its path.

[Maxim]

I solder test signal wire to R31, Test signal appear only when I notice that probe divider set to X10 and change it to X1. That's OK.

Some advices:
1) Why you not use screwed connectors for probe and test signal wires connected to main board? (Now those should be soldered)
2) Why in instruction you not write about divider position on probe?

Questions:
1) When I change HPOS on screen move "Trig,Point" but "Hor.Position" unchanged. (Marks on screen as shown in User Manual)
2) Not work connection to jyeLab (No device detected) and AVRUPD. I change COM5 to COM2 - not help. Maybe problem with BOB1. How check it? (I use USB powered mode)

[jye1]

Thank you for suggestions. The enclosure was not designed for this product originally. So some designs were not to the best.

For Q1: Did you see trace moving when you change change HPos?

For Q2: Have you installed driver for CP2102 chip?

[Maxim]

Yes for both questions

I notice new thing. When I move HPOS - "Trig,Point" mark on screen moving in right direction but "Hor.Position" moving in opposite direction.

[Maxim]

O.K.
I resolder BOB1 and jyeLab and AVRUBD connected.