It looks like you have got a bad connection in the clocks wiring circuit i would start with your fuses you will need a workshop manual for your model which will tell you which fuses cover the display,make sure these are clean & in good condition,after that you will have to go into the clock & look for bad connections make sure the battery is disconnected before starting on any fault finding.
rpm and speedometer gauges not working 1995 Chevy silverado 2wd
That sounds like a problem within the engine control module or possibly the wiring,
If the speedometer is not working but the odometer is, I would suspect the dash cluster is at fault. If both speedometer and odometer are not working I would suspect the speed sensor on the transmission is at fault.
If the speedometer is not working it probably needs a new speedometer cable. If the speedometer is actually broken either take it to as speedometer repair shop or replace it.
Broken cable?
It died of Chevy Envy
If both the speedometer and odometer stopped working it is probably the speed sensor in the transmission gone bad. If only the speedometer quit you may have to replace the dash cluster with a reconditioned unit.
There are several possibilities why the speedometer is not working. The VSS, vehicle speed sensor may have failed or become unplugged. The speedometer may have failed, or the ECM, engine control module, may have failed or there could also be wiring issues.
The dealer has to program it.
Someone knocked a wire loose.
Sounds like the speed sensor is bad.
IF the speedometer is not working it is because the computer is note getting a signal from the trans. and will not tell it to shift. Try replacing the speedometer the sensor in the tail shaft of the trans.