DSO 068 assistance required

[Robert Taylor]

I having a little trouble with my DSO 068 kit that I would like a little help with.  I'm unable to complete all of the tests on the analog side, as voltage on AV+ is reading at -500mV.  I have tested the components referred to in the flow chart:

• L4 inductor: hovers in the 4-9 ohm range
• C23 electrolytic cap: reads 100uF on my meter's capacitor setting
• C9, C10 ceramic caps: reads 100nF (0.1uF) on my meter's capacitor setting

Following the rest of the chart, V- is normal, AV- is normal, VA+ is normal.  With SW1, SW2, and SW3 set to GND, 10mV, and X1; V2 and V3 both read at ~100mV (not 0V).

Other challenges I've experienced:

• I was missing one 10k ohm resistor, but I was able to supply it with one that I had on-hand.  This is in R30 on my board.
  
• The assembly sheet refers to a 0 ohm resistor for R13, which I assume means a jumper wire, but I can't find an R13 on my board.  This might be a board revision thing, as my board is configured slightly differently from the one pictured in the instruction sheet.
  
• The display does not change from GND for any position that I place SW1 in.
• Shorting JP7 to enable the buzzer causes ADJ to not function after the device is powered on.  Pressing ADJ will turn it on and it will boot all the way up, but it doesn't respond to input after that.
  

I'm a hobbyist, not an engineer, so I'm reaching out to this group for advice.  Thanks in advance!