Tektronix TDS3012B Date & Time slip

[Gangway]

Just asking if anyone knows if this scope has back up battery for date & time. My unit panel mounted, so pain to open up.
Cheers

[tautech]

Not looked but the info is probably here:
http://w140.com/tek_tds_3000_series_service.pdf

[Gangway]

Thanks for link, had already scanned this document, but no info or circuit drawings relating to clock source backup.

[Jwalling]

There is a Dallas DS1742W PDIP with an internal battery. Yours is probably dying.
Part is EOL (Dallas/Maxim sucks!)

[Gangway]

Thanks JW, that sounds like the issue, 10 year life span. Will have a look in the new year, cheers mate.

[Gangway]

Jw
Just found your previous reports re this bad NLA chip & other excellent  articles about modifying it for external battery cell. Had no idea this chip was a known dud. So when the battery goes flat, I guess the cal data goes.

[voltsandjolts]

No, cal data will be fine.
I have replaced a 3034B BBRAM with a blank device and was all fine - BBRAM just seems to store instrument setup (timebase etc) and date time.

[Jwalling]

Jw
Just found your previous reports re this bad NLA chip & other excellent  articles about modifying it for external battery cell. Had no idea this chip was a known dud. So when the battery goes flat, I guess the cal data goes.

You won't lose the factory calibration, but you will lose the SPC constants. You'd have to run the SPC  before using the scope.

[TheNewLab]

here is a YouTube. explains, and does with clever temp solder of a battery so the CMOS never loses the settings


However, if date/time does not keep..and the battery is dead..that means calibration..Others on this forum would know more about the latter