[Kenwood] TM-221a won't transmit

[Don Ashe]

	Dear list:
	
	The Kenwood customer support guy referred me to this list for help 
with my rig. (after advising me to buy a new rig instead. Perhaps he's 
right...) I hope someone can help. I combed the list archive for 
similar problems but the only one I found had no responses.

I have a TM-221a which receives perfectly, but won't key up. All other 
functionality is correct.
	I can see the PTT input to the CPU toggle when I key the mike, but I'm 
not seeing any data clocked into the PLL. When I hit the up or down 
buttons I can see the input pins toggle and watch the clock voltage 
dip, so I should be able to se the PTT do the same.
	 I checked the schematic from the service manual, and I can't see 
anything between the CPU and the PLL that could selectively interfere 
with the transfer of data, so I'm assuming that the CPU for some reason 
is choosing not to send the transmit command to the PLL.
	I have looked at all of the inputs to the CPU, and I cant really see 
anything that would cause this- the SWR and APC circuits appear to 
operate after the PLL switches to transmit mode, so I can't see any way 
for that to affect the CPU. The manual doesn't mention anything that 
would relate to this, either.
	Has anyone seen this before?


thanks!
-don
KE5DQL