[Elecraft] Problem after installation of KSYN3A - no TX power (not direct related)

[Johnny Siu]

 Hello Group,
This morning, I installed the new KSYN3A to my colleague's K3/100.  The installation is easy and DISPLAY gives an indication of SYN1 ok.  RX is working well.
However, the K3/100 gives no TX power output even I set below 12W solely using the LPA.  I then discovered that the supply power voltage was 15.7v as indicated in the VFO B display (I later turned it back to 13.8v for further testing).
Apparently, the installation of the new KSYN3A should have no relationship with the TX problem.  Since the K3/100 did not deliver any power, TX calibration could not be done.
I tried to put the setting via the MENU of KPA3 to PAIO ON or PA BYP or PAIO BYP but still no TX output.  The KAT3 was set to BYP as well.  All test under a Bird 50 ohms dummy load.
Before approaching Elecraft support, could any of you give me some directions for trouble shooting?
Thanks in advance.
73
Johnny VR2XMC