Tektronix 2445A with problems

[fant]

A company gave me a Tektronix 2445A just for nothing after many years not powered.
At power on appears the diagnostics error as the following picture.
Indicating TEST 04 FAIL 13 error

After few seconds it disappear end the scope is working, but on the readout bottom row, the data are mixed with ?, as the following picture.

Any idea what to search?
I have the user and service manual.

Thank you in advance

 

[factory]

Calibration data has bad checksum according to the manual, test 04, LED CH4 lit, error 1x.

David