Re: P3 display flashing on/off.


Joe Subich, W4TV
 

I then discovered the flashing stops on the P3 while the K3s was
keyed up (PTT button on the front panel mike) and resumes when
un-keyed.
PTT is a red herring ... The display update is suspended in transmit
unless you have the TXMON option installed (which does not appear to
be the case).

73,

... Joe, W4TV


On 2020-06-30 12:39 PM, W9BIK wrote:
Hello fellow K3'ers...
Last night my P3 display started intermittently flashing on/off rapidly.  The entire display would rapidly flash on/off, including the border lines, function key menu, waterfall, etc.  Sometimes this will happen once, then again anywhere from several seconds to several minutes later. Other times it would start flashing and continue to flash rapidly for several seconds, then stop, then repeat a few seconds later. Every now and then it would start flashing continuously and I needed to cycle power on the K3s and P3. Very intermittent to say the least.
During my preliminary troubleshooting I noticed the flashing would stop when I disconnect the serial cable between the K3s and the P3. I re-seated the serial cable on both ends multiple times in an attempt to clean the contacts to no avail. I also re-seated the ribbon cable inside the P3 to no avail. I also tried re-seating the IF cable connecting the K3s and P3 multiple times, although the flashing would continue regardless if the IF cable was connected or not.  Thinking the serial cable may be intermittent, I tried moving the cables around, during both flashing on the display and when not flashing, and that had no effect. I also tried running a separate ground wire between the K3s and P3 - no difference. Note that this setup worked fine for a few years and just started happening.
I then discovered the flashing stops on the P3 while the K3s was keyed up (PTT button on the front panel mike) and resumes when un-keyed. This happened both in the K3s TX mode (RF out) and in the Test mode (no RF out). This, together with the flashing stopping when the serial cable is disconnected, led me to believe the K3s is at fault and not the P3.
So, before going any deeper into the troubleshooting, has anyone else experienced this issue or possibly have any insight as to its root cause?
Thanks,
Chuck
W9BIK

Join Elecraft-K3@groups.io to automatically receive all group messages.