I got an old pinball machine with a dot matrix display. One of the vertical lines is flickering/going out. After asking in a pinball specific forum, others suggested that the IC for that line could be defective. I cant find others with the same specific fault, majority have a line that is not working at all. And there is a fix for that, where you have to drill into the display to attacth a new wire. Anyway, is there a way to figure out if the chip it self is defective? The chip is a HV7708PG, not sure how good it shows in the image on 4chan. I measured from the glass to the chip, and there is a connection all the way. The resistor on the way there measures the same as all the others 21.8K ohm. I looked at just buying a new chip, but its rather scares with places that sells them. And some of the ones that do charges 45€ for the chip + shipping. So i kind of wanna know IF its the chip that is defective.

Only "Solution" i came up with, is to switch the two chips on the board. Since 1 chip only covers 64 pins, and the line has 128, there are 2 of the same chips. Otherwise im kind of clueless what to look for.