I fixed an Agilent 34970A datalogger

Thread Starter

mcgyvr

Joined Oct 15, 2009
5,394
Just wanted to share my fun.. I was borrowing an Agilent 34970A datalogger for some temperature measurements... The other day I powered it up and the unit just kept rebooting/losing power... I felt so bad that it broke under my watch so i called Agilent who charges a flat $750 to fix it (ouch!)...
So I decided to open it up and take a look.. Found a ruptured 3V lithium memory battery soldered to the PCB... Ordered a new one for $8 bucks at Newark, soldered it back in and... All fixed horray!!! Saved myself $742...
 

BMorse

Joined Sep 26, 2009
2,675
good work & congratulations.

since when do people solder a battery directly to PCB - i thought it was best to use a coin cell holder.

There are a lot of devices that use 3 volt cells for memory backup where they are soldered onto the PCB via solder tabs on the battery.... this saves the manufacturer a few cents from having to buy a separate battery holder when mass producing devices...


B. Morse
 

Thread Starter

mcgyvr

Joined Oct 15, 2009
5,394
Well it had 2 solder tabs welded to the ends... Seems silly to me too as the battery only has a 3-4 year life span... But of course Agilent wants to get the 750 when the battery goes versus the user simply uncliping the battery and replacing easily.
 

BMorse

Joined Sep 26, 2009
2,675
They usually don't expect the device to outlive the battery since the battery is used only as a memory backup....

here is one from one of those credit card swipe devices/ Signature Pad found at just about all supermarket checkouts....

soldered Battery.jpg

You would think NCR is a big enough company to where they would spend an extra few cents to put in a holder.... But then again, this way, they could charge almost $800.00 to replace the battery!! :)

B. Morse
 

Thread Starter

mcgyvr

Joined Oct 15, 2009
5,394
Just shows you that electronic devices/cars,etc... are not designed to survive, they are designed to fail (and hopefully gracefully).
Not a bad gig... Sell a product for $2,000. then every 3-4 years make another $750 just to replace an $8 battery (probably $1 their cost).. and on and on...

This Agilent unit usually just throws up an error code about lost memory but due to the battery rupturing (thankfully it didn't catch on fire like other lithium batteries) this one just kept rebooting... Ruptured battery still measured 1.8V too.
 
Top