I decided to dust off the old antminers and set them up again.

Ive pointed them to szbpool and they work for a few minutes but then bfgminer just stops. Ive tried both versions of bfgminer and tried using them through med miner assistant and on their own. Even if I set each antminer to run on its own bfgminer they all stop working at the same time, usually after just a few minutes. Any ideas?
What driver you use ?
for windows Zadig install driver for cgminer, and not work properly with bfgminer,,,,,for bfgminer use Silicon Labs CP210x USB to UART Bridge VCP Drivers
working solution for Windows + Antminer U2 + Silab driver + MED bfgminer 2 gen
bfgminer.exe -o stratum+tcp://medwk.szbpool.net:8078 -u user.x -p x -S antminer:all --set-device antminer:clock=x0981
OR as i write earlier
use MED bfgminer like proxy
start MED bfgminer 2 gen with option: --http-port XXXX
and point your miner to ip:port XXXX , you can use any regular miners soft which support your miners (not MED Modified), CPU will reduce asic speed when reach bottle cap
this is discussed already here long time ago