[Elecraft] KAT2 help: menu parameter shows "--"

Thu Jul 3 07:12:01 2003

In-Reply-To: <[email protected]>
Pete -- If you look at the Control Board schematic (page 24) you'll see 
that pin 7 of U4 corresponds to the output of the unused half of the LM358 
so I doubt the 5V is relevant.  To be honest, I'm not sure what an op-amp 
is supposed to do when its + and - inputs are both tied to ground, but....

More relevant is the "--" display which suggests that the K2 isn't talking 
to the MCU in the KAT2.  Triple-check that U1 and U4 are installed right 
way round and that you haven't got a bent-pin under U1.  Also check the 
resistance between pin 1 of J3 and pin 40 of U1 -- you should see around 
470 ohms.  

73, Dave GW0LUA

--------------------
Pete, W6WY said:
> I'm at the point where I'm doing the preliminary tests and I tap 
> MENU and scroll to ATU and get only a "--". I went to trouble-
> shooting and verified all connections to the K2, both boards for
> shorts to ground, solder bridges etc. All looks OK. Current drain
> is OK.   The voltage checks are all OK  EXCEPT U4 pin 7 shows 5V
> and the manual says it should be zero volts.   Any ideas out there
> on where to look??   Thanks in advance.......

73--Pete W6WY