[TowerTalk] 20 meter stack problem

[Cqtestk4xs at aol.com]

I came back from vacation to find my 20 meter stack not working  right.  To 
make it short, the bottom stack 100/50 is fine, SWR is the  nominal 
1.2-1.5.  Of course if one part has to go, it is the top one.  
 
The top stack, 200/150 is the problem.  Directly connected at  the base of 
the tower the SWR is around 3.5 and drops to around 1.7 at around  15.6 mHz. 
 I have not gone up the tower yet to check it out hoping to get a  couple 
of suggestions before doing so.  Physically, from the ground, the  antennas 
look fine, and with the SWR at least getting near a "normal" reading,  even 
if out of the band, I think the baluns are good.  The  antennas are M2 with 
1:1 baluns.
 
I do have a phasing harness made up of a tee-connector with two 1/4  wave 
75 ohm matches leading to the two antennas as well as a couple of a other  
coax connectors.  My hope and thinking is that perhaps one of these  suffered 
some water intrusion even though they were pretty well  waterprooofed.  
Since I wasn't home, and we did have t-storms, lightning  could also be a source 
of the problem.  By the way since the antennas do  have baluns I checked 
the resistance and it was about 1 ohm....pretty much what  you expect, but 
that could be due to a short on the line.
 
Any ideas before I climb?    I plan to take my  trusty MFJ259 and a 
multimeter and check all connectors that I can  reach.
 
Bill K4XS