SL 500 sleep mode problem

[brendon b]

Hi

I'm new to this forum and to lenovo/thinkpad.

My SL500 (type 2746 32G) cannot be woken up after being put to sleep.

I put the machine to sleep by pressing the power button or Fn - F4. I then try waking up it up by pressing the same again.

After trying to wake up there seems to be hardware activity e.g. the hard drive spins and the sleep indicator light switches off. But the screen stays blank.

This problem developed over a period of time. Initially sleep mode worked fine.

Any ideas? I've done a search here and on the web and have seen similar problems, but no solutions. Bios upgrades don't seem to work.

brendon