DSO138 oscilloscope problem

[hakraf]

Hi,
After soldering all the parts of my DSO138 oscilloscope kit, everything seems to be working, after powering the board with 9,23V and touch the red clip with finger as mentioned in the user manual nothing is showing (No trace), I noticed that the switches doesn't working, after some troubleshooting i found the voltage is not correct at L3 (RF-choke) as showing in the next photo

the voltage at that point is -1.36v instead of 5v.
My problem is i can't found this part in the market, so can i short it or use something instead ?
Thanks in advance.

 

[(*steve*)]

Are you sure the polarity of your plugpack is correct?

 

[hakraf]

Yes it is correct, this board come with 3 pieces of Rf-choke, i replaced L3 with L2 part and it's work correctly

 

[debe]

I had a similar problem, theres 2 x 3term regulators one pos other neg 5V. Check you haven't soldered them in the wrong position or around the wrong way. They are hard to read.

 

[hakraf]

I checked that also and all parts are in the correct position and correct way, like a said i changed it with same part that come with the board for L2 and it is work correctly