[1000mp] New problem with FT1000MP

[Scott Manthe]

Ken,
Here are comments from VR2BG to the Yaesu list in 2002 regarding what 
seems to be a very similar problem.

73,
Scott, N9AA

> I think Marko will find a switching diode for the 7.5~14.5 Mc input BPF
> circuit blew.
>
> Pop covers, set rig up on an effected band, then touch the inside of the
> diode furthest "inside" from the antenna for the suspect BPF section, then
> the inside side of the "outside" diode.
>
> Sorry, I don't have the service manual here with me to be more specific, but
> when a nasty SO2R incident left some bands deaf on my MP & an IC-765,
> it was very easy to identify what had went by poking around with a
> screwdriver - you should be able to hear receiver spring to life as screwdriver
> acts as a mini-antenna & bingo, bad diode is identified.
>
> 1N914s work great until one can find a more appropriate replacement
> component.  And when you're not sure what blew the original diode(s) in the
> first place, 1N914s are more suited to sacrificial duty.
>
> In my case, something very nasty came out of an Alpha that blew internal
> doorknobs to pieces & created an occasionally intermittent relay in an
> external antenna switch.  The two rigs were on antennas just 4m apart or
> so & both had external BPFs.  Alpha on 40m yet MP blew 15m internal
> BPF diode.  Alpha was not transmitting.  765 lost several bands' worth of
> diodes in one go.  Alpha still dead one year on (no time to fix).  Extra
> seemingly irrelevant info provided as after the smoke literally cleared, I
> expected internal BPF passive components to have become toast, but it
> was only diodes in both rigs.
>
> Good chance you're just a diode (the one on the input side to the internal
> BPF) away from getting rig fully operational again.
>
> 73, BW2/VR2BrettGraham