NVRAM replacement in a Tektronix TDS3014

[TechCB]

Hello everyone,

The TDS 3014 series are great oscilloscopes. However when the batterie of the  DALLAS DS1745-150 starts to fail its frustrating to find a replacement that works.

First things first, desolder the Dallas chip was painful since I do not have a Desoldering Tool. So, if you find yourself in the same situation I will recommend to use solder wick. Using a desoldering pump may cause damage to the board (lift traces or pads). Make sure you cut off the part of the solder wick that you already used to avoid loss in the heat transfer.

I'll recommend to use a 24 pins socket, to make it easy in the future to replace the NVRAM. If you are having a hard time getting the DALLAS chip you can use the M48T02-150PC1 it works fine, the only thing is that the DALLAS chip has a supply voltage 3.3V while the M48T02-150PC1 needs from 4.7 V - 5.5 V.


Voltage supply is on pin 24, so, if you used a socket you could cover the hole on pin 24, bend the leg of the chip and solder a cable you can connect to pin 2, 3 or 4 of J900. Once you turn ON your oscilloscope you will see the screen turns pink  really frustrating after all that effort... But it has an easy solution, just press SAVE/RECALL → FACTORY RECALL SETUP → OK CONFIRM FACTORY INIT.

Don't forget to configure the right date and time.

I hope this was helpful 

[james_s]

This has already been discussed at length in another thread. I designed a little adapter to replace it with the PowerCap version which has an easily replaceable battery. I also worked out where the power-on hours is stored and manually set that to the correct value in the replacement part prior to installing it.

Surely if you can afford such an expensive oscilloscope you can also get your hands on a proper desoldering tool? It will cost you a lot more than the cost of even something like a Hakko if you write off the scope by mangling the board trying to get the NVRAM out. I would not even consider trying to do it with wick.

[TechCB]

I'm glad you found another solution to the same problem.

I replaced almost 20 NVRAM on the TDS3014 with solder wick and works fine. Anyhow, this is another way to get the same results, without an adapter.

[james_s]

The adapter is only necessary if you want to use the PowerCap package so you can easily replace the battery again in 10 years when you may not be able to get the chip anymore.

I've also replaced the batteries in the potted Dallas chips but that's kind of a pain and the result looks messy.