Tektronix DPO30xx fails SPC, but why?

[dzseki]

At work we have a Tek DPO3034 (hacked to 3054), that fails SPC.

The instrument has a serial starting with C01XXXX, on which the software bandwidth upgrade is not working theoretically, but in our case it did.
In fact after the hack the SPC still ran fine, until one point, but not anymore. There haven't been any noticeable event to the scope why it shouldn't work, and indeed the scope works quite well as far as I can tell, but it fails SPC.
Now, running SPC from the scope UI does not tell much information why is it not passing. Is there any way to see a detailed log at which step the procedure fails?

[mikehank]

You can put these scope into service mode by pressing the multi-purpose buttons on the right of the display.  Press 1(top) then 3 twice and then 1 again.  This will give you more detail as to your error.

[mikehank]

A common failure for the DPO3K's is Nrej.  This is fixed by putting metal tape all over the inner covers.

[dzseki]

You can put these scope into service mode by pressing the multi-purpose buttons on the right of the display.  Press 1(top) then 3 twice and then 1 again.  This will give you more detail as to your error.

I tried this, but nothing happened, when exactly should I push these buttons?

[mikehank]

You may have to be in the utilities menu.  I can't remember its been a number of years since I worked on these scope.  Also some FW revs have different buttons to be pushed.  Try holding button 1 then hold button 3 then push button two holding them all down