Tektronix 2465A Test 06 Fail 01

[branadic]

Hi folks,

after a while I wanted to use my analog scope 2465A to take some measurements. The scope was unpowered for a while.
After turning on the scope the selftest stopped with test 06 fail 01. After a while of search in the web I found, that this indicates a low or high voltage level of the internal memory backup battery. I've never opened the scope and never touched the battery, so potentially an under voltage was causing this error during selftest because of the batteries age.
The original 3.5V 750mAh Keeper LTC-7P lithium cell seemed to be unobtanium. However I found LTC-7PN Lithium EVE EF651625 3.6V 750mAh and ordered it immediately:

LTC-7PN

Today was the day of operation. After unwrapping the scope and extracting the board I was able to measure the voltage of the backup battery. It measured ~1.9V so high time to replace it.
Since the memory needs to be powered during the replacement I used a 2x Mignon AA battery holder with 2x AA 1.2V rechargeable battery giving 2.4V in total and soldered the battery holder as described on:

Tektronix 2465A DV Oscilloscope Memory Backup Battery Replacement

to the board, before I started to desolder the original backup battery.
A few careful ten minutes later the original backup battery was removed. Soldering the new battery to its place was easy going. After putting everything together and powering the scope everything worked fine without any errors. So the memory content is save for the next years. Brilliant. 

-branadic-