On Sat, Mar 29, 2025 at 09:57 AM, Jay Czaja wrote:
Thanks again guys! The 2247A has been running overnight with signals in each
channel and everything has been humming along ok, no lockups.
Just replace the 3V battery to get rid of the annoying power up error message and the recalibration routine running every time. You need to lift the main processor board that is on top, and the battery is at one end of the board. To lift the board there are some flat ribbon type conductors and connectors to deal with, but if you are careful and methodical its pretty straight forward procedure. Last time I recall the battery swap can be done by just partially lifting the board, which limits the amount of ribbon cables to deal with.
I have a really nice 2245A and enjoy using it and always wanted a 2247A.
The 47A is a 45A with additional digital functions (and push buttons), otherwise they are identical scopes. Make sure to check those suspect diodes on the power supply board in both your 45A and 47A scopes. A quick glace should tell you if you need to replace them. The power supply board is in the middle of the lower side, kind of a pain to get it out and even more pain to get it back in due to the connecting pins. But you should be able to read the labels on a couple of diodes without removing the board to make sure you don't have any time bombs sitting in there.
If you find voltages and ripple specs are ok I would not even bother recapping unless you see a capacitor that is obviously leaking or bulged up, which I doubt.
These 224x scopes if I recall used high quality Mallory or Sprage caps, and I've never bothered to replace any in my 47A, but most definitively had to in my 2465B.
Those old caps sometimes even end up measuring better specs than modern equivalent caps (value/ESR).
