Battery died in standby mode, laptop won't turn on

Hello - I hope someone can shed some light on this. 

I have a roughly 3 year old Studio 1557 which has had almost no problems to date. I recently was travelling for a few days and had left my computer on standby (by closing the lid) and unplugged. The battery drained, and when I returned there was no charge left. Trying to turn on the computer resulted in no response.

I took out the battery and tried to start through only AC power. Th charge indicator LED lit up momentarily, but otherwise no reaction. I tried running it from the battery, and then charged the battery (which worked fine - charging light on and battery indicates full charge) and tried again. I also tried holding down the power button with no battery or AC connected. In all cases the power indicator was off and the power button did nothing. 

This happened me once before, two years ago, under warranty. In that case it fixed itself after 1 day, and attempts to replicate the problem were unsuccessful, so I never got a replacement. As I said, apart from this, I have had no other problems, and doubt that I have a major motherboard issue, etc, givenhow specific both errors are.

Any tips or advice would be massively appreciated. I'm doing field research in Bangladesh at the moment and will have no chance to get to anything like a proper repair centre for weeks.

Thanks!