Question AC disconnects when CPU/GPU throttling

[Jem777]

Hi All
I own a Gigabyte gaming laptop, model PA55, since around one year after buying it i started having problems with it. What its doing is that when gaming the AC power keeps disconnecting and running on batteries. It will do this every few seconds so a few seconds on AC then a few on batteries then the AC connects again. On some days it does not do it. When the AC disconects, the games run like in slo mo, i assume its throttling.
Ive cleaned the cooling fan but it was not full of dust. Can i run some software which can produce a report to shed light on whats going on?
What else can i try?
Thanks

 

[Dave8671]

First lets try removing the battery and run on AC just run it no games. See how long it runs.

 

[Jem777]

Thanks Dave, the battery is built in but i may be able to disconnect it internally. If i run the laptop on AC and im not playing any games, the AC doesnt disconnect. Im about to install MSI Afterburner to get an idea on temps. Hopefully it saves a log to file.

 

[Jem777]

I ran MSI Afterburner it showed the GPU'S temp at 56 celcius. How do I upload the report which it produces? I dont see any icon for attachments

 

[mark1776]

This sounds like it is the power supply, either in the computer or external to it. If the power supply overloads it will turn off to protect itself. If something is wrong there, then it may be disconnecting below its rating. I would measure the voltage from the supply when it disconnects to see if the problem is external or internal.

 

[Jem777]

good answer Mark, im suspecting something like that. is there a utility that i can run so it can monitor the laptop?

 

[Jem777]

i found this

https://windowsreport.com/test-computer-power-supply-software/

ill try HWMonitor and AIDA64 Extreme
if they give me a report ill post it to see if it gives any clues.

 

[.Psychosis]

Your charging port or cable is broken if AC disconnects sporadically. The throttling is by design. When a laptop is disconnected from AC, the cpu will drop to a lower multiplier to attempt to save battery power. You may be able to force a higher multiplier with ThrottleStop if you wish, but your battery will suffer. Drawing that much power from the battery can damage it permanently.

 

[mark1776]

good answer Mark, im suspecting something like that. is there a utility that i can run so it can monitor the laptop?

The fact that your laptop is dropping to battery is enough to indicate that it detected a problem with the DC charging input. What I would do if this were my problem is get a scope hooked across the DC power leads between the supply wart and the laptop. Then I would hunt for the power transients. If the cycle is long enough, you can get by with just a volt meter instead of a scope, but the oscilloscope is the tool of choice in this case. If you don't see a cutout on the outside cable, then open your laptop and hook up across the power input jack and try again. If that doesn't reveal the source of the problem, then you should probably take the laptop to be repaired by a competent specialist shop. Unless you realy know what you are doing, the chances of causing additional damage probing the electronic inside the laptop is near certain, as you will need special probes and a microscope or very good magnifying glass.

As Psychosis indicated, it could be the jack or the cable, in which case the "wiggle" test might be revealing. Wiggle the wire and plug to see if you can induce the failure. If yes, then put the volt meter into the plug and wiggle some more to see if that causes voltage to cut out. The most likely cable faliure points are the plug attachment and the other end near the strain relief. The failure could be an electronic one as well, but check the mechanical stuff first. If the power jack has cracked the solder joint to the motherboard or broken a terminal lead, the fix should be relatively simple. If the problem is electronics on the motherboard, then that is much more difficult to troubleshoot and repair. Most of us are not equiped to do surface mount repairs. If the problem is electronics in the supply, then get a new supply.

 

[Jem777]

I have done the wiggle test without it cutting out. Inside tthe laptop there is a small circuit board with the DC jack on it. Whenever it starts cutting out, i take the back off the laptop and remove the 4 pin cable connecting to it. I blow it out abit and funny thing it then works fine for a couple of weeks. Im thinking it may be that circuit board.