There are a few people out there struggeling with their 4052's :
On ftp.dreesen.ch/FTP/TEK4052 they will find description, schematic, pictures and romdumps for the Diagnostic ROM pack, as used by the TEK engineers in the day. Also listed are the the TEK-supplied CRC's for all ROMS in the 4052/54 systems. No special components used, so nothing to stop you building your own Diagnostic pack. If anyone does so they can contact me if they need further info. Jos