Re: Again about IPX: serial output



graham salkin wrote:
Ok, perhaps "Drill out the battery" is the wrong phrase.
What i mean is drill out the little plastic bit at the side where the wires end go from the plastic backpack down to the chip.

Heres some pictures of one of my earlier hacks.

http://www.salkin.co.uk/~wiki/admin.php?replacing%20the%20M48T02%20battery

Although it is possible to drill it out, its not nessesary. You would have to make sure you drill through the plastic backpack but not the chip covering itself. You only need to drill out the edges.

If you are feeling brave though, apparently the battery is in the right side of the backpack, and the crystal is in the left, so as long as you could drill it and not penetrate the chip carrier too much, its possible.

However the FAQ gives a better description than i could.

http://www.squirrel.com/squirrel/sun-nvram-hostid.faq.html

sdsf wrote:

graham salkin skrev:

The lines:

WARNING: TOD Oscillator NOT Running, Kickstart in Progress ...
Incorrect configuration checksum;
Setting NVRAM parameters to default values.

suggest that the NV ram is dead or dying. (Which isnt too surprising on a machine that old)

A good indication that you have a marginal battery is the fact that the machine will seem to work for a bit. (The dont just fail, the NVram just becomes more unreliable until its unable to hold values during a powerdown at all)

The Non volitile ram and Time of day clock is held in an internally battery backed up 2k ram chip of type M48T02 on an IPX.

For more information see the excellent resource at :
http://www.squirrel.com/squirrel/sun-nvram-hostid.faq.html

You can either replace the chip or drill out the battery and solder a new one to it if you dont mind a bit of DIY.
Its looks a bit daunting, but its actually pretty easy. I have fixed the NVRAM in a number of sun4c machines with no issues so far.


Is there a guide to "drill out" the battery?

An X-ray of the M48T02 would be nice :-)


I just use a utility knife and carve into the plastic a bit on the end, it's pretty easy to expose the metal contacts and solder wires to them.
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