[Elecraft] K3 button problem question

[Dave Hachadorian]

Interesting. I also have several buttons that don't work on my 
K3:
band up
mode up
ant
shift/lo/norm
rate/lock
NR

The radio is still usable, and I'm waiting for a break in the 
contests to send it in for repair.

Dave Hachadorian, K6LL
Yuma, AZ


--------------------------------------------------
From: "Paul Ferguson" <Paul at PaulFerguson.us>
Sent: Saturday, April 17, 2010 7:28 PM
To: <elecraft at mailman.qth.net>
Subject: [Elecraft] K3 button problem question

> Seven of my front panel buttons do not function on K3 #757. I 
> also used the
> Switch Test to see that they give no scan codes. All other 
> buttons work OK.
>
> Looking at the the schematic for the "Front Panel - Switches" I 
> see these seven
> buttons are all connected to the SCANADC0 line into U3. I took 
> off the front
> panel and put an ohmmeter from ground to the SCANADC0 line, and 
> it gives a few
> ohms. The other lines (SCANADC1-7) show as open.
>
> I looks like either U3, C30, or R27 is bad. Does anyone see any 
> other
> possibilities?
>
> I don't relish replacing U3 since it is a 16-pin IC. Maybe some 
> Chip-Quik or
> tiny cutters to snip the leads would ease the job.
>
> 73,
> Paul
> K5ESW
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