Hi all
About a year ago you helped me fix a Tek 2236 scope which is doing well ever since, for which I'm thankful.
I'm planning to tackle the refurbishment and / or repair of the 2445B/2465B scopes that I have before I move on to the older ones.
The 2445B boots up fine, but shows no trace. It smells of capacitors after a minute or two, so I don't use it any further. The 2465B works fine, but I have the feeling it has some issues focusing over the whole CRT. Either the middle looks sharp or the edges.
I started taking the 2445B apart and took out the PSU boards. The capacitors aren't good anymore (they are visibly leaking) and there are those dreaded RIFA caps on it too. I understand that both these scopes have the same or similar PSU and therefore I'll probably just replace all of the electrolytics on both boards, except the two large ones.
Are there any specific guides or recent capacitor lists available? I see that there are many threads and discussion about this. If nothing speaks against it, I would just replace the PSU electrolytics, the RIFA caps and the surface mount capacitors on the side board like for like for both scopes.
I also see that there are those Dallas NVRAM chips on board, I know them from old computers. While for an old mainboard they just hold meaningless CMOS setup data, I understand correctly that for this series of scopes they contain the calibration data?
Any suggestions on backing up these values? On some old mainboards I dremeled the Dallas chip battery contacts and added a regular lithium to it, but I would like to have a copy of the data before I attempt it here.
I have some old stock of these chips too, but I would have to check the remaining charge as well...
Thanks for any pointers.
