Zenith 5G500 trouble shoot

I have 5G500 and trying to get this thing working. The only tube that heats up is the rectifier tube. Still new to this could be a small fix.

This is a battery set, and, all tubes, except the rectifier rn at extremely low filament voltage. Does the radio play??

Be sure if you remove any tubes to test or replace make sure the radio has been turned off for at least 5 minutes. If you remove any tube while turned on you will destroy the filament(s). (You don't need to ask how do I know this )

When you turn it on, does it hum at all? Do any of the other tubes feel warm at all? You may have to get some spare tubes for the radio to see if you have a bad tube. Have you given it a good looking over inside for broken wires and such? Just some things to get you started. You have asked for help so let us know where you are with this. Thanks.

The only tube that will light up / get warm is the rectifier tube.  Verify the B+ voltage at the rectifier cathode and at the plate or screen of the 1LB6.  Check the filament voltage at pin 8 of the 1LB6 for 5.5 +/-.5 volts, 0 or much higher than 6 V indicates an open filament somewhere.  (check the filament voltage at pin 1 of the 1LB6 only if you have a steady hand as a slipping probe contacting pins 1 & 2 of the 1LB6 could vaporize a filament (don't ask how I know))