Bought a stack of scopes at an auction before. All scopes were in great shape, except for the only Tek I bought. Being a 4ch, 500MHz beast it's just too good to abandon.
The scope was offered with a known issue: very low brightness. I first hoped it could be cranked up in a menu (and the auction Gremlin missed it) but allas: already cranked up to 100%. Barely readably at 100%, pretty much gone at 90%. Unfortunatey, missery didn't stop there: tried the diagnosis menu and none of the tests completed: scope hanged, rebooted... So: off with it's head!
PS: If anyone has the service manual for this thing, I'd be grateful...
Four screws release a part of the backcover. Figured I would need to undo all these screws at the back first, but the entire shell slides off, no trouble!
This reveals the main logic board. Some custom Tek chips and a whole lot of discretes! Very clean layout and not a patch anywere. Actually, I haven't found a single scratch or patch wire anywhere in this entire unit! This board is not screwed anywhere. There are two plastic spacers keeping it in place, as soon as you remove those, the board slides right out (after you unplug all connections off course). There is a pushbutton, rocker switch and DIP switch. I'd love to know what these are for...
Note how the flatcables have an additional connector that is not used. This is the 1M unit, I guess another logic board is added for the 2M unit. A bit odd: aside from the flatcables, there's a PCB connection as well. Not sure why not a simple flatcable, too high speed? Dunno...
Back of the logic board: again ultra clean. Only decoupling caps here...
Flipping the unit reveals the analog part Again: pretty damn clean. Note the cast shielding piece for the AFE. Beneath the logic board there's only metal casing/shielding with the PSU and CRT circuitory beneath it. To get to it, the backpanel and a lot of screws have to go:
Not much there: some coax for the trigger/aux, a small circuit board for RS and parallel ports.
The PSU and CRT. Looks pretty damn good for a 15+ yo unit except... Hang on.. What do we have here?
Bulge much? I'll be fixing this before going any further. To be continued!