Hi everyone, newbie here, i have the rev4 6 digit board, ive attached att tubes with fly leads, also all LEDs, i have a very strange issue, on start up all tubes start to count 0-9, however they miss out 5 + 6, also 3 tubes flicker on number 3, ive checked all connections are firm and soldered, im wondering if there could be an issue with the tubes or the KI55D1 chip, thanks in advance for any advice
Could you connect the 5+6 cathode leads to the output of another digit (e.g. 1+2)? Although it is improbable that all tubes have defective 5+6.
Are you really, really shure that there is no problem with connections of the K155 to the socket, of socket to the pcb, of connector SV5 to the PCB and of leads to PIN for digits 5+6 of the socket (you could measure resistance between the respective pin of the K155 and the cathode of the tubes, should be at maximums a few Ohms).
Posting mainly to get subscribed to the thread. IAN! The moderator emails appear to be broken again.
I can only reiterate what others have said: these types of display problems are almost always solved by thorough inspection and repair of the wiring to the tubes or perhaps the soldering of the K155 pins.
Look into it later when the dust is clearing off the crater.