[Yaesu] Re: PB1315 a cooked?

[Carol L Maher]

Ed, I don't think your audio board had anything to do with the fact that
you
lost output power.  Sounds to me like you lost your negative  bias
voltage
and the tubes ran away turning red. This is real bad !
As per your statement
"tubes in the final compartment glowing very brightly and smoke coming
out "

In this case of your sniff test, this can be very misleading !!
Once smoke starts to come out of things, it's very hard to put it back in
!!
The smoke cold have moved from under the chassis and appeared to come out
by the
audio board. Or It just appears that way. Who knows.

Very carefully.  Pull out the finals, discharge it first once
you remove the PA stage cover.   Put the final tubes aside for now.
Leave the plate cap leads hanging in free air. 
If you feel uncomfortable doing this but the cage cover back
on  the final section so you don't get hit by
the 700Vdc, but be careful and make sure
the plate leads are not going to hit ground or you'll be
fixing your H.V. power supply on top of the other problems
you already have..

Then plug in your audio board and try the rig again.  See if you have
your receiver working again. Then take it from there.  If not, you need
to fix
the receiver first and make sure you have 12 VDC in the set, NOTE  you
should also have a regulated 6 VDC and the easiest way to see if it's
there is to look at the red VFO LED on the front panel. 
If the RED VFO LED is lights up with the VFO in Internal, then your
6 VDC supply is working.

All said and done if the receiver is working then you
can proceed on to the final stage.  You need to check for a negative
bias voltage and screen grid voltages.  All these voltages should be
spelled out in your service manual, owners manual or followed out
on the schematic back to the power supply (If you don't have a
service manual handy).  If you need the service data it can easily
be found on E-bay any given day of the week.

That's about all I can tell you for right now.
It's also very strange that your mic gain control froze up, but I
don't think it had anything to do with all the other problems
your having.  Anything is possible, but it's very
unlikely. You'll have to take it one step at a time.  
I may just have a spare microphone gain control for you some
place when you are ready for it down the line.

Got to run.
Best Regards
Carol Maher
W4CLM