[Kenwood] TS-850 RX/TX Switching Problem, D31 Checks Good

[Robin Midgett]

Hi Gang,
I have the service manual now. I seek the help of those familiar with the 
TX/RX switching problems in the TS-850. It was recommended to me to check 
D31; it checks good in circuit with the diode junction test on my DMM.
Does D31 fail such that it checks good but doesn't function properly? I've 
seen transistors behave like that, but never a diode.

In RX mode, the symptoms are: no RX audio, On Air LED dimly lit, TXB is 
hovering at 3.5 volts, RXB is at 0 volts.

It seems to me something is either leaking TXB voltage, or something is not 
turning on RXB.

Suggestions on where to look, please?

Thanks,
Robin Midgett KB4IDC
VHF+ Glutton EM66se