My oscilloscope has a diagnostic error+ E5311+ E5312+ E5313+ or E5215. What does this indicate?

My oscilloscope has a diagnostic error+ E5311+ E5312+ E5313+ or E5215. What does this indicate?

These diagnostic error codes indicate a problem with the communication between the Executive Processor and the Display processor. The executive processor either did not receive the expected response from the Display processor, or the Display processor is not receiving the expected data from the Waveform DRAM , Display Data Buffers, Display Gate Array, or the MMU (Memory Management Unit) interface.

Due to the age of these products, replacement parts are no longer available. Repairs on these products are available from Tektronix Service on a best effort basis.