Julian's Kit Build (FAIL): Banggood £15 ($23) Oscilloscope Kit

https://goo.gl/bBs59D Enter to see the secret sale page at Banggood.
Spent a few hours building this Banggood (jyetech.com) oscilloscope kit, but the display failed after just a couple of minutes of use. Also, the negative analogue voltage isn't working because there's no pulse train coming out of the CPU. Otherwise the CPU appears to be working fine. All a bit of a mystery. http://bit.ly/1RzsbiM DSO138 DIY Digital Oscilloscope Kit Electronic Learning Kit