What do I do if it's computer based and still going crazy?

Question

follow up to lube of speedometer cable question. Speedometer "line" goes up and down at random, occasionally does not move at all, do I need electric repair?

Answer 1

Sounds like you have a digital style instrument cluster.
Yes you probably do need electronic repair.
You can remove it and take it to a speedometer shop (or ship it) for repair or exchange.
Before you do that though, as you drive, pay very close attention to ALL the other gauges and see what they do, and what they do when your speedo is acting up. Make a note of it, and pass this info to the repair shop. It will make the repair much faster, and MAY save you some money.