It looks like you have an aftermarket LED board from DF4NW. Nice! However that suggests that someone botched the install and gave up on it.
The display is strobed. One set of segment drivers drives all the digits, and the data is clocked through to each digit fast enough that you see no flicker. Since most of the digits show all segments that means your segment drivers are good. That leaves you with the segment driver connections to the bad digits and the digit LEDs themselves. You can check the LED segments individually using an Ohmmeter as you would any diode. These are common anode displays, the pinout can be found online or you can trace it out from the schematic.
You can tilt the front panel down for easy PTO access by following the procedure in section 2-18 of the service manual. Be careful with step 5, go slowly and watch for any band switch sections that may want to stick to the shaft. Check soldering in the PTO.
73
-Jim
NU0C
On Sun, 21 Mar 2021 07:25:15 -0700
"Mike Davidsohn G3ZCC" <mike@...> wrote:
Thanks Steve.
Both digit one and two are missing the two segments I think..
You may be right about the soldering, it was a mess so I re did it .
Will check again? and also look at the drivers.
I am wondering if it is something to do with the connections on the 100k? resistors that go between the? four and two displays.
Have had to pull the board out as I have a PTO issue to sort first.
Both my spares are not working so have to fix the one in the TR7.
The lamp holder has damaged the cog on the adjuster so trying to solve this before moving back to the board.
Kind Regards
Mike
G3ZCC
Jim Shorney