Tek TDS3012c CPU error

Simon Spiers

Hi guys .
I have been passed a failed Tek 3012c scope from a friend working in a calibration house here in the UK.
I was told that the unit was faulty and needs a new CPU.
However on boot up all seems fine and after about 15 seconds it comes up with a screen saying the self check has passed.
Then comes the confusing bit, A few seconds later a smaller screen comes up saying something like there is a hardware fault and mentions the CPU.
The scope from what I call tell works perfectly, I have not tried FFT or other more specialised settings, but generally you would never know there is a problem.
There are some codes in the fault log, can I use these to narrow the fault to component level.
Thanks in advance.