Towards the end of 2002, the Electrical Engineering department at my university gave away some hardware they didn't want anymore. I scored a Sun Microsystems SPARCStation IPC. I had to overcome many difficulties to get it to work, but the most formidible challenge was changing the NVRAM battery.

I was able to boot the machine, but it couldn't operate on my network. On a SPARCStation, the MAC address is stored in the system's NVRAM. My MAC address was coming up as ff:ff:ff:ff:ff:ff, indicating that the NVRAM most likely had a flat battery.

The SPARCStation IPC uses a 48T02 NVRAM. These can be purchased on the Internet, but the cost comes to about AUD$30. Even worse, I would have had to wait a week or two for the new chip to be shipped to me.

From the Sun NVRAM FAQ, I discovered that it might be possible for me to attach a new battery to the old NVRAM, saving me from having to order a new one. I figured that I might as well give it a shot. The chip was already useless, how much worse could it get?

The original battery is stored in a package with the oscillator on top of the NVRAM. On one side of the NVRAM, there is some resin which covers the contacts between the battery and the main chip. At first I tried to melt the resin with a flame, hoping I could then scoop it out and get to the contacts. That didn't work. The resin doesn't melt. I tried cutting it with a stanley knife, but it would've taken years to get anywhere with that approach.

I eventually took a more heavy handed approach. I put the NVRAM upside down in a vice, and used a high speed drill in a drill press to bore into it. After bit of this, I was able to see the contacts I needed to get to.

picture of NVRAM underside with a cavity drilled

After I had found the contacts, it was a fairly simple matter to solder some wires to them. The solder didn't really want to stick to the contacts, but with some luck I got it to stick eventually. I then soldered the wires directly to a 3 volt lithium battery.

picture of NVRAM with wires and battery attached

The internals of my IPC are fairly compact, and there isn't really any convenient place to put the battery. I ended up using blue-tac to stick it to some plastic moulding near my video card.

picture of the old NVRAM with a new battery attached, in the motherboard


toojays@toojays.net, 16/4/2005