Driver corruption my friend.
It's not unheard of, in fact sometimes you can't boot correctly because of it and can get bsods.
Just to be safe I'd do some benchmarks with it. Or sell it and let people know what happened. If it was the...
This may be old. But it's now possible to overclock the t7600g with bioses that don't allow the option using throttlestop. Just thought you should all know. I've tested it.
By selecting the correct powermizer setting you can lower the vcard to 1 volt instead of 1.32 volts. That will help battery power.
I'd attempt to adjust mem voltage too with software if possible. Along with that, change screen...
Worst case scenario you need to bake one day and then you just keep it downclocked forever till you get a new card / lappy. Never overclock long term an integrated vcard unless u dont care about the lappy.
Turn off wifi / disconnect it and try again. It could really almost be anything. Rams a big one too or just a plain old corrupt OS that needs reinstalling.
Anyways, I'm waiting on you zzpulp to answer before I do this about what and how to do this chainboot what notness, before I go ahead and see if we can advance the e1705 one more time