Intermittent No-Start Condition - '94 C280

[jgl1]

'94 C280 with 53K miles has an intermittent no start condition - when the ignition key is turned, all instrument cluster warning lights illuminate and then nothing else happens: no clicking sound, no starter activation, just silence. Repeated start attempts are typically unsuccessful, as is jiggling the key in the ignition switch. Then, perhaps 10 minutes later the vehicle starts and runs flawlessly. The no-start condition is quite random, happens infrequently (6-8 times a year) and does not appear temperature/weather related.

The vehicle has had this problem since new; despite repeated attempts, the dealer has been unsuccessful in locating the trouble - no fault codes are ever displayed. The ignition switch has been replaced but the problem continues.

Any suggestions? TIA.