TCAS II Honeywell TPU 67A

[Spanner748]

Need HELP! Our TCAS II system isn't working! TCAS STBY in blue comes on but as it is turned into TA/RA mode; the display with range stays ON for about 3 secs then; TCAS in Yellow comes on.
No fault code on TCAS Processor. Internal fault code display 'F9' on ATC Transponder. Replaced transponder. Fault code stayed ON.
No fault code on TCAS/XPDR control unit. No input from Encoding Altimeter. Altitude Digitizer installed instead.

Thanks in advance for any help extended to solve this mystery.

[Spanner748]

TCAS system tests OKAY on ground though !!

[Basset hound]

:)M.E.L. :8 :p :)

[Spanner748]

Found faulty Altitude Digitizer.

[bhushan]

Dear Sir
I need a help .I am working in 1900D beachcraft which is having TCASII CAS67A .I have one problem in both Aircraft that TCAS yellow flag is not going off most of the time .Some time it goes but most of the time it remains and TCAS NOT COMING TO STANDBY OR IN TA,RA mode.I have changed the TPU 67 but snag remains same.