Thanks Adrianni for the videos and the information. I also get the same problems from my Tektronix 2465b which I bought a year ago and I barely used it; and although its number of hours on duty reported is reasonable, I forgot it.
As soon as I got it from ebay, I clad it with a heat sink and replaced a lot of caps.
Now I also get among trig'd flashing, error 04, Fail12??? A lot of
? Down the readout, and no sooner I turn it on, than the trace disapears.
I wonder what sense it makes placing a precious and vital Chip that glows hot during operation in such a poor cooling environment! What sense does it make fastening it with bolts and screws when it is soldered and while the glowing bottom is seperated from the cooling surface! It is instead connected with the PCB copper area through two star washers!??? Hanging in the hot stream of air!
Last nigt I made an adventure and dismantled it to get the A1 board, not so easy especially managing to loosen the jammed screws in the front and keep the Delay Line laid on the pins of the Chip out of the way! I managed to desolder the Chip. I intend to place it on a socket and to thermally couple it to the PCB underneath it by a copper plate bound to an Aluminum heat sink on top.
If I still get problems I will think of designing a horizontal amplifier no matter the digital sacrifice, and modifications, I have no other choice get the best of its analog merits!
Last night I said to myself I could be happier with a "plug and go" and reliable purely analog Tek485 or a Kukisui COS6100. I miss the Philips PM3295 which had a minor repairable power failure, I sold it to get this Tektronix!