View Single Post
  #13  
Old 12-31-2020, 07:52 AM
DaveWM DaveWM is offline
VideoKarma Member
 
Join Date: Feb 2009
Location: Orlando FL
Posts: 5,607
those are nice sets, I have one as a daily watcher. sounds like the CRT is being biased off, turning the set off releases the bias as the residual HV pulls the electrons thru.

check HV anode voltage 19kv

check the voltages at the 3 cathodes of the CRT IIRC should be around 100v-110v. These are driving by the collectors of the 3 video out transistors.

The grids all get voltages from boost voltage, so if you lost that, then you will have cut off the tube. boost is about 500v check pin 5 (common screen grid) on the crt should be upper 400's the common control grid also from the boost is upper 90's (pin 7)

My guess is you lost the boost.

Last edited by DaveWM; 12-31-2020 at 08:09 AM.
Reply With Quote