generic power supply reducing CPU to minimum (0.48Ghz)

trif

Distinguished
Nov 13, 2009
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18,510
So I bought an adapter for my HP 350 G2 that let me plug in a standard 5.5mm OD 2.5mm ID connector, found a 19v power supply (slightly less than the OEM 19.5v, but whats 0.5v amongst friends?) and assumed all was well,

It didn't charge the battery but if it was full or nearly full, it still would be at the end of the day, except my laptop got really really slow,

after a lot of investigation, it turns out that as soon as i plug in the charger the CPU is under-clocked to 5x multiplier (i5-5200U) - this is not the automatic power saving, I'm on high performance and if I run prime 95 on battery the CPU goes to over 100% usage - 2.4+Ghz in CPU-z as soon as I plug this charger in I can watch it drop down

Why is this and how can I stop it?

Thanks,