Guys - I've just had a bit of a shock and think it's worth sharing here...
I have a Lynx 2. Rediscovered it in the loft a year back and whilst delighted was reminded how awful the screen contrast was. Well, a new one from McWill and it is now everything it ever should've been. I've bought a few new games and am loving playing on it again.
The PSU I've been using is the one I had with it in the first place and was a 'proper' Lynx one rated at 9v. Seems to work fine but I've been starting to think I should check it - not in the least with a few on here painfully experiencing their Lynx going (quite literally) pop.
I measured the voltage across the PSU out and nearly had a fit - 14v!!! It may well be it drops to the correct level with load but no thank you. I cut the lead off it and am now using with a regulated supply at 7.5v (I haven't upgraded/replaced the power reg components in mine and this seems a happy medium as 6v flashes the power light).
So if you haven't checked recently, get a multimeter and test the voltage across the power plug.
Safe Lynxing...
Dan