>Gordon Tyler wrote:
>
>> Hi. I've just received an almost mint '92 486dx system . . .
>>
>> One problem: I want to replace the clock battery. I tried to remove
>> it but it is solidly in place between 2 prongs. Below it are 4
>> vertical gold pins.


Gordon:

With those soldered-on 486 batteries, there usually is
an external battery connector with four pins, usually
labeled JP1 or JP2. The middle two pins (2-3) are jumpered
to utilize the internal battery (your replacement
candidate). Pins 3-4 are usually the CLEAR CMOS settings,
to drain power from CMOS, to reset it to default.

The replacement battery will come with a wired connector
which has 4-female connections, with the first and last
wired to the battery terminal and these connect to the
external JP battery connector pins 1 and 4. Obviously,
the external battery connector cannot be plugged in with
pins 2-3 jumpered (internal battery), so you have to remove
the jumper, which disables internal battery power.

As has been pointed out, you should remove the old battery
to avoid corrosive effects, although it is not necessary
with the internal battery jumper disabled (open).

Get the specified battery type and voltage (check the manual).
Computer parts stores usually carry PC batteries for $6-$10,
though there are some odd-ball voltage batteries that cost
more. As Jose said Radio Shack has them. Also Best Buy and
Circuit City may have them.

Regards,

John Chin

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