1997 Other Mitsubishi Models Select Gauges are Intermitent

Thank you for responding to my question.
1997 Mitsubishi Mirage LS Coupe 1.8L

The Speedometer, Tachometer and Odometer are malfunctioning in unison. Upon start-up, All 3 together are OFF or ON, intermittently. While they can turn OFF during vehicle use, they never turn ON. They only come ON upon removing key from ignition and trying again (still random - maybe 1/8 chances). When ON, they are accurate and do not bounce/fluctuate/flutter or malfunction in any other way. Check Engine light is OFF - no warning problems. Bumps on the road, pounding on dash, hot/cold temperatures, even humble begging seem to have no effect on the gauges.
All other gauges, lights, signals, warnings, etc. On instrument panel work perfectly, even when the Speedo/Tach/Odo are OFF.
I have read similar posts and tried various things:
All fuses are good. I removed instrument cluster and resoldered every single contact on main circuit and the individual circuits for the Speedo and Tach. I checked contacts with a meter and found no shorts/breaks.
The 3 gauges are obviously linked and dependent upon a separate mechanism/circuit, but I cannot identify it. I checked ground leads and all was fine.
Any suggestions are appreciated.
-sancho