Hi Pityu,
2 buffers seems to be damaged, but all 4 should be replaced at once. They can be damaged e.g. when you make wrong connections and programming in circuit with external power supply (programmer can not limit external power supply and a high current from external power is going through these buffers).
There are 2 options:
1. you can send programmer to our service and we will repair it (shipping address the same as on invoice). Please include issue notes and shipping address for return.
2. you can try to replace it if you have such possibility, please check details below
Inside are 4 protection buffers SN74CB3Q3245PW in TSSOP-20 package. When you open programmer, you will see it without problems on the bottom side of PCB. When you replace it, please make hardware test again. All values should be green. There is a big chance that everything else is fine (they are protecting other circuit).
Example stores where you can find it:
https://eu.mouser.com/ProductDetail/Tex ... HeSJ3uo%3dhttps://uk.farnell.com/texas-instrument ... CB3Q3245PWhttps://www.tme.eu/en/details/sn74cb3q3 ... struments/https://www.digikey.co.uk/product-detai ... -ND/864361Please remember to replace all 4pcs (it is very important).
Hope it helps. If you need any more information please feel free to ask.
If you prefere to send it to us, please remember to include contact information.