Hello, I have a dell dimension 8400 (very old) worked great, then after some time not used I got a 'system battery voltage low' I changed the battery now it won't reboot. I get for long beeps short pause 2 more long beeps. I tried repeatedly hitting f2 to get to set-up to reset bios but it won't go into set-up
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Did you install the battery with the proper polarity? Usually the + side faces away from the board.