I have a Lenovo Yoga 500-15ibd laptop that I recently bought (used). Everything in it seems to be fine but whenever I plugin the charger it slows down. I looked at the task manager and I saw that as soon as I plugged in charger, the CPU speed goes to 0.48GHz and stays there no matter how I use laptop. Everything becomes extremely slow. As soon as I remove the charger, it goes back to 2.2+ GHz like it should.
I looked at internet for the issue and tried following:
- All drivers are up to date. BIOS is up to date
- Some reported that the charger could be faulty, but I used another Lenovo charger (and and HP charger with adapter) but they all yielded same results. I know that the other two chargers are fine
- I changed the power plan to change minimum CPU state to be 100% at all times
- I removed drivers related to battery and restarted computer as many times
- I let it charge to 90% plus to see if its just something related to low charge
- I enabled virtulization as this was mentioned as one of the fix (was disabled before)
- While running on battery only, it runs for a while and I cannot say that it just stops as soon as I plug the charger out. The battery seems to be old but I think I can run for about 45-60 min before it discharges completely.
Looking at the charging port in laptop, it seems to be clean and fine. But I just cannot understand why am I losing power while on charger.
Is there any way to diagnose the problem? Could this be problem of battery or the charging socket in laptop? Or a windows driver issue?
Anyway the any software can tell me what is power input that laptop is getting so I can check it against specification if its same?
Edit
So I tried a few other things, like disconnecting battery and running on power directly and even changing the charging port with another the I knew worked correctly. But still the same issue.
Then in one of the forums I read about ThrottleStop and how we can disable and lock turbo power limit. I could not find the option there and I just looked around for a while, but then in main window I saw in red that it said BD PROCHOT. I didnt understood the UI much but when I unchecked it, the speed went to normal on charger as well. Then I checked a little bit more on it and I understood this should be send signal to CPU to throttle. It seems like this protocol is triggered as soon as I connect charger even through I can see that CPU temperature is under 40%. So I unchecked it and saved it and things went to normal. However, still when running extensive tasks, the CPU and GPU throttles but it still stay above 2.0GHZ.
One more thing that I observed was that battery would charge very slowly. Not sure why is this, but it seems to take long time to fully charge. I ran the Lenovo diagnostics on battery and they did not report any error but I though it may be worth mentioning.
This however is not permanent as I have to disable it everytime. I am one step closer but still dont know what is cuasing this and hot to fix it permanently
