[R-390] R-390 won't power up...

[Terrence Harvey]

Hello All;
 
First let me preface this post by saying I am not and elex tech. or engineer and so not a lot of expertise in the field. 
 
    The foregoing having been said... I am trying to get my Phila-51 contract R-390 back on line. Went down some time ago in failure to power on mode when function switch turned to any position. Seemed likely to me the panel mounted micro-switch had failed ( replaced it about 5 yrs ago with similar failure mode), so took receiver off operating table and put aside for future repair. 
 
Recently I got around to taking front panel down and testing switch with an ohm meter.Testing revealed switch functioning properly, so re-assembled and re-applied power, thru Staco variable transformer, with same result. No tube filaments, dial lights or audio. Next checked continuity of 3 conductors of power cord with all ok. Power present at chassis side of AC input receptacle. Checked 26Z5s and they checked good on Simpson tube tester. This is where I stand at this juncture. 
 
What are next most logical checks I need to perform???
 
Thanks for any/all help.
 
Terry Harvey
Crystal Lake, IL USA
terrencelharvey at yahoo.com