Yaesu FT101ZD "killer cap"
This Yaesu FT101ZD (MK3 version) was purchased new by my
father in the early 80's.
This transceiver has made very few connections in its
life.... The last 30 years this TRX has not been in use.
I got this from my father, and had to do maintenance service.First I had to clean all potentiometers and all switches,
Yaesu FT101ZD top view
for this I used PCC cleaner, DO NOT USE CONTACT CLEANER!!
Then I replace the "killer condenser" if it fails, the full
300 volts will be applied to the grid of the 2nd power tube in the PA.
This causes the power supply transformer to draw all the current
it can supply....result?....a defective power supply transformer
and defective finals.....you then 
have a demolition set. It is
therefore important to renew this capacitor in advance.
Normally the original is a 1KV version, when replacing it is better
to have one of 3KV.
Click here to see the fotoalbum of the replacing the "killer cap"
Click here for the service manual of the Yaesu FT101ZD
The old "Killer cap"
The location of this capacitor is under the PCB board where the 2 PA tubes are located
The new cap (3KV)
Please see the column Yaesu FT277ZD! (this is the same transceiver as the Yaesu FT101ZD)
Here you can see a Youtube film from the repair, servive and replament from the "killer cap"