Hi. I have a Compaq Presario R4000. It's around 6 years old. Until recently it has worked as well as any other laptop with the usual software problems. Yesterday I tried to switch it on and all I see is the charge light flashes once for around 1 second then goes out. No response at all from the machine. Tried running it without the battery but still no response. A friend told me that it may be the battery and that some laptops won't run without a battery inserted. Any ideas would be appreciated. Cheers.