Hello I have an IBM A21m 2628 pIII 800mhz 128 mb ram running win me when the laptop starts up the cooling fan comes on for approx 30 seconds (maybe a little longer. then it shuts off during post and does not come back on. After about 5 minutes the laptop just shuts down. No warning no nothing just like you had disconnected power does not matter if on ac or battery it does the same darn thing. if you disconnect and reconnect battery and ac power laptop comes right back on. would really appreciate some help here thanks buckwert