I opened my Tektronix 4054 to begin troubleshooting last night.

It last worked in 2000 after I bought it, but it had not been used for many years - and after moving to my new house 10 years ago, it simply popped the main fuse.

I followed my 1983 4052/54 4052A/54A Technical Data manual to remove the cover and begin troubleshooting, hoping that there would be lots of similarities to the 4052 troubleshooting that I'm still doing - but waiting to receive a replacement Tek custom display IC from an EBAY auction.

It looks completely different - other than the ALU/MAS/I-O boards.

And I believe the I-O board is slightly different than the 4052 I-O board, because I have the 4054A upgrade kit which replaces two of the boards including the I-O board, but haven't installed that kit yet.

Here is a photo of both running my port of the Byte Magazine Hidden Line BASIC program in 2000: