mistafeesh
Getting at the backup battery in a 117MHz model, or the backup batteries in the 133 and 166Mhz models, needs almost complete disassembly of the PB1400. Even then it is a finicky task because of its location and the routing of its leads. You need to be very sure that the backup battery problem warrants the greater problem of replacing it/them. The backup battery is only 50mAh in capacity, intended to preserve the contents of memory in the two minutes of sleep time that succeed the third and last warning about low power in the main battery. It will continue to preserve the contents of memory for about a day, giving you plenty of time to replace the main battery with a charged one, or to connect the AC adapter. However, replace the main battery you must.
The backup battery's capacity is small. Tiny even. What can mislead owners into thinking that it is malfunctioning is that it does not begin to recharge before the main battery is completely recharged. When backup battery power is interrupted the sleep LED lights continuously. The Power Manager chip then needs to be reset by holding in the reset switch (between the ADB and serial ports on the rear of the machine) for at least 20sec, and often up to 60 or more sec., before trying to restart. If the PB has been allowed to run down beyond normal, and has turned itself off, you need to leave the AC adapter connected for up to 24hr after the Control Strip (main) battery indicator shows that the main battery has been recharged.
If you find that resetting ('zapping') PRAM results in one chime followed by shutdown, this is usual enough to be 'normal' in the PB1400. Use the reset button to restart the PB. The behaviour does not, in itself, indicate that the backup battery is defective.
If you find that backup battery replacement is, in the end, what you wish to do, it is part no 922-2429. US eBay sellers such as
powerbookguy,
powerbookfixit and
showbert2, or the UK seller
powerbook_fanatic may be able to supply it, but it may not be new.
