[toyonpeak]

I recently got an EZTRAK SX in remarkably nice condition to use in my home workshop. I haven't cut anything yet, but all seems to work fine. I got the Original Bridgeport system Disc with Version 2.25/4/43 software and I am booting the machine on copies I made of that disc. I bought a set of manuals from machinemanuals.net and they are very helpful and complete with one exception: the Installation and Operation Manual describes the motherboard as a 286 and my SX has a 386. After searching Motherboard sites, I believe it is a Jetpro Infotech MB-3A, or something very close. It is populated with an ALI chip set; a photo is attached here.
After reading many threads on this very helpful forum, I inspected my CMOS battery and found it to be exactly at the stage George has described as about to distroy my motherboard. See photo, the battery is mighty fuzzy ! Since I don't have specific information on my motherboard, I am hoping someone can instruct me on safely replacing or adding a new battery. In the close up battery photo you can see a jumper across two pins that must be for use of the internal battery, but it is not clear to me if I should move it to the neighboring set of pins to use an external battery, or simply open the existing jumper. Also, where do I connect the new external battery?
Related question: If I simply remove the existing battery in order to clean the area and either replace with new battery or solder wires to another battery, will I loose information I can't easily replace?
Any help would be greatly appreciated. Also, if someone has or can point me to a Manual which describes by 386 borad ( i.e. manual with Chapter 5 for a 386), I would be anxious to get it. Thanks.

PS I just posted this but don't know where the pictures I attached went???

[BptRoadman]

If you power up the system you can change the battery without losing anything. Eye it up before you attempt anything. Make sure the area is clear and you have the proper tools < a nice pair of thin needle nose >

If you are the shakey type ... get into the bios screens and copy all the settings ... power down ... change battery ....power up and recheck the bios.

I've never had any problems doing it either way

[NC Cams]

If the battery is soldered to the board, first power up the machine using a regular external keyboard and press the DEL key while it boots so as to get to the BIOS.

Record the settings - all the settings.

Power down and change the battery. Use care if you have to desolder/resolder it from/to the board as nicads can blow up from overheating.

Repower it back up and use the DEL key trick to go back to the BIOS. Reset as needed and save. Continue on with booting.

If the cell is a nicad, precharge it or else leave the machine on for several hours to fully charge the battery.

If the batteries are alkaline or other similar type replaceable ones in an external "carrier", simply replace them WHILE THE MACHINE IS POWERED UP. This way, the M/B will never know the batteries were missing.

[machintek]

I replace the Nicad by removing the board and using a solder sucker (Radio Shack) and a soldering iron. Have not had a battery blow (yet). Then I solder in a new one. If you have the book on the mother board, it will tell you where to attach an external battery 9usually a lithium just a bit bigger than a 9V). It usually comes with a "pig tail" and a plug. Yes the jumper is moved to external AND THE OLD BATTERY IS STILL REMOVED. You can even use small diagonal cutters to snip it out without removing the mother board (depending upon location.)
Lastly you can get creative and buy a AA lithium sold by radio shack and a AA battery holder some wire and create an external back up battery. I do this for the parameter battery on turret servo drives on DAEWOO lathes. But I use 2 battery holders in parallel so a new battery can be installed each year and the old one removed without the loss of the parameters.
CMOS, follow the above advice in the prior posts.

George