Clean the pins on your 5U4G rectifier tubes and make sure they are seating firmly in their sockets no matter how you turn the chassis.
Cleaning tube pins and sockets is so important that I always do it BEFORE any recapping.
http://antiqueradio.org/FirstStepsInRestoration.htm
Every tube, new or old, needs to make clean connections inside its socket, or all bets are off.
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html