OK, pin 16 on U3 reads 4.967V, (essentially 5V) so it appears it's staying at 5V and not being pulled down.
Inspecting the solder on pin 16, it doesn't look like a cold joint. > On Aug 7, 2024, at 11:46 AM, William Santos <san...@mac.com> wrote: > > Thanks Dave, > > I will open the 2 up and test with the multimeter when I get home from work. > I'll report back with the voltage I see. > > I do have a scope, but haven't used it much and never hooked it up to a radio > this complex before. > >> On Aug 7, 2024, at 11:43 AM, Dave Van Wallaghen <d...@w8fgu.com> wrote: >> >> Bill, >> >> Don and Mike have you looking in the proper location on the Front Panel >> Board. I suspect that the RIT/XIT pot does not work as well, but as you say, >> you can't invoke RIT or XIT at this time to determine this. Something is not >> allowing the /BANK2 signal to occur in order to scan those controls on the >> right side. FP U3 P16 is where that signal originates. Maybe a cold solder >> joint on U3 P16 or something shorting the /BANK2 path to a high voltage. >> >> If you have a scope, you could look at U3 P13 and see it being pulled down >> in around 5us pulses as I am measuring here. If not, then you might try >> using a DMM to measure that pin. I am seeing around 4.6v and it fluctuates. >> If it is at the high 5v level, then it is not being pulled down by U3. >> Again, either something keeping that line high or bad pin 13 on U3. >> >> 73, >> Dave, W8FGU >> >> >> >> On 8/7/2024 11:45:30 AM, "William Santos via Elecraft" >> <elecraft@mailman.qth.net <mailto:elecraft@mailman.qth.net>> wrote: >> >>> Hi Mike, >>> >>> Thanks for your response and attention to my issue. >>> >>> Yes, it is only the buttons to the right of the LCD that are affected. >>> >>> All of the pots to the left of the VFO knob work properly, as do all the >>> push buttons on the left (BAND+ through NB). To the right of the LCD, I can >>> only confirm the MODE(1) and ON/OFF buttons work. Buttons A/B(2) through >>> MSG(9) do not elicit a response. Unable to test the -1 0 +1 potentiometer, >>> as I think all of it's functions require actuating one of the buttons on >>> the keypad. >>> >>> To summarize, buttons 2 through 9 on the keypad are nonfunctional, and >>> everything else seems to work. >>> >>> Thanks and 73, >>> Bill >>> KN6UDK >>> >>>> On Aug 7, 2024, at 8:23 AM, Michael Carter via Elecraft >>>> <elecraft@mailman.qth.net <mailto:elecraft@mailman.qth.net>> wrote: >>>> >>>> Hi again, Bill, >>>> >>>> I re-read your post and realized that >>>> it's only the buttons to the right side >>>> of the LCD display that fail to function >>>> (with the exception of the MODE button). >>>> Is that correct? >>>> >>>> If so, I will retract my statement about >>>> the parallel load shift register not working >>>> properly. If it works for the buttons to the >>>> left of the LCD display, then the shift >>>> register is working OK. It would then >>>> seem that the BANK2 switches to the >>>> right of the display are not being polled. >>>> The /BANK2 signal that polls these >>>> switches is generated in U3, a 6B595 >>>> shift register. That shift register >>>> receives data serially from the MCU >>>> and produces the /BANK1 and /BANK2 >>>> signals that activate each switch >>>> bank in turn. U3 also generates the >>>> /ENC_RD signal that allows the >>>> main tuning knob to be read. >>>> >>>> Please confirm which controls do >>>> register any response, including >>>> the 4 potentiometers to the >>>> left of tuning knob. >>>> >>>> Thanks, and 73, >>>> Mike, K8CN >>>> ______________________________________________________________ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:Elecraft@mailman.qth.net >>>> >>>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>>> Please help support this email list: http://www.qsl.net/donate.html >>>> Message delivered to san...@mac.com <mailto:san...@mac.com> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net <http://www.qsl.net/> >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to d...@w8fgu.com <mailto:d...@w8fgu.com> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
