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Quoted from undrdog:I have a display where all of the digits work, but they look terrible (pictured).
That pictured display might have a faulty 4543 decoder chip (weak outputs except for the 'g' segment). If changing the decoder chip doesn't fix it the glass is probably bad.
Did you also replace the 100k ohm resistors at R7, R9 and R11 on the display with missing digits?
If not, post pictures showing the missing digits, another of the PCB component side and lastly of the bottom of PCB side.
Quoted from undrdog:and went on to switch out the decoder chip from my parts board with the one on the display pictured above. Didn't help. Looked the same to me, although I wouldn't rule out getting the two pulled chips confused and putting the same one back on
If you think that you put the original suspect decoder chip back in, you can check it with a multi-meter.
Put and hold the Black meter lead on pin 8 of the decoder chip.
Using the red meter lead, measure the resistance at pins 9, 10, 11, 12, 13, 14, 15 of the decoder. Pin 14 is for the 'g' segment which in that display is showing good at all digits. The other pins should measure the same resistance.
Swap the black and red meter leads and remeasure. You should measure the same resistance across all pins.
Next, put and hold the black meter lead on pin 16 of the decoder. Remeasure the same pins (9 through to 15), they should all measure the same. Swap the black and red meter leads again, and you should measure the same across all pins.
Faulty/weak output pins will usually measure differently in one way or another to good output pins.
Note the resistances are are quite high, if you don't have an auto-ranging multimeter, set it to 20M ohms range.
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