[Elecraft] KAT2 bridge null adj.

[Allan Glasdam]

Hi guys
After receiving great help from Don off list with the KAT2, I have a new 
"problem"
KAT2 assembly and operating instruction page 16, second from bottom 
says: adjust C55.  Hold in TUNE button and release when...
Adjust C55 as close as possible to 000.

When I press TUNE the display flashes ATu and then reads 000 constantly 
until I tap menu. It´s not possible to get any movement when turning C55.
T1 on KAT2 is rewound, soldered and checked.
Any suggestions? I would be glad for a hint, where to search.
73
Allan OZ8A