" Problem I had was I never got a gigabit connection cos I guess my ethernet cable is too long." Ethernet spec supports cables up to 110 Metres long. Probably you are using eBay cables that are not...

The software hasn't changed. Works here.

(To factory reset, hold down the link button for about 15 seconds as you power on the unit)

All LEDs off even when initially plugged in means that the unit is bricked or dead. Try the firmware recovery utility posted by me elsewhere on here. If it doesn't see the adaptor at all then it's...

Buy a kit, sell the spare unit on ebay.

I would not advise using such an old kit with your expensive 9020. There are some known compatibility / performance issues between the 9020 and the earlier adaptors. TP-Link have released updated...