The internal battery of my new Apple IIGS (ROM 01) was dead completely, so it cannot hold some setting value like date time, screen color, slot configuration, RS232C value, and so force.
I decided to replace to newer one. This article shows how to replace the internal battery of IIGS ROM 01, with almost easiest working.
Open up the IIGS, remove power unit (just unlock with one notch in front sidem and pull out the power line), you’ll see the big battery just half size of AA.
Unfortunately the ROM 01’s battery was fixed to main board and cannot replace easily. I planned to replace with new battery holder for replacing in the future.
Here’s a picture of dead battery. Fixed with solder to mainboard.
Cut out the lead line of the corner of “L” by nipper, leave the “I” line for attaching new battery holder. Don’t remove the whole lead line completely if you want to avoid hard work of solder operations (might be damaged to the main board).
The completely dead 1/2 AA size battery was made on March, 1987. Vintage one. It might almost same birthday as my IIGS itself.
I ordered new battry box with lead line, and new 1/2 AA battery for replacement. You can purchase them at some electric parts shop with cheaper, just 300JPY each (almost 3USD each). You can also find them in ebay, but much higher price than parts shop.
To avoid solder operation for avoding big damage to the IIGS main board, I replace the lead line of the new battery case to another capped line as below. Just a easy work with solder. Well done.
Just cap the new lead line to the left “I” line (from older battery) of the IIGS main board. Upside is plus, so place red line to here. The original place of the battery is little smaller than the battery case, so placed the new battery holder to the side of mainboard, with double-sided tape.
Re-attached power unit and connect the power line to mainboard. Completed.
Test power on, and set date time and screen color, and power down. After some second, power on again, and you’ll see the new setting screen color and date time already set.
If not, check the lead line of the battery holder. Good luck.