Plugging in power lead causes weird symptoms

[devil81]

Hi Everyone:

I'm repairing a friends laptop, its a fairly old Toshiba Satelite Pro A300 which suffered a BSD and refused to load past the XP loading screen and would shutdown and restart repeatedly even on battery. I solved that by doing a clean install but now when I plug the power adapter in various things might happen 1. It will shut down and restart repeatedly 2.Freeze with pretty colours and lines appearing on the screen 3. Work for between 3 to 30 minutes and then repeatedly shutdown and restart.

My question is this could the power adapter be failing as I had to repair it a few months ago as the same friends pet chewed through the insulation and core wires. So I soldered the wires back together, used heat shrink tubing and an electrical tape covering over that to complete the repair. It has successfully worked for months and even now will charge, turn on the laptop and the connects are as solid as the day I did them, with no visible damage or wear, although when I tested the multimeter voltage it was 17.9v compared to the quoted output of 19v.. So am I missing something or is my friends laptop simply feeling its age?

Thanks in advance for any help, its appreciated.

 

[Vnxc]

Its possible the cord is the problem. But if it is doing these things on battery then there is another issue.
Any water damage?
Does it get very hot?

 

[devil81]

Its possible the cord is the problem. But if it is doing these things on battery then there is another issue.
Any water damage?
Does it get very hot?

Thanks for the quick reply, no these issues do not reoccur when on battery, so I'm leaning toward the power adapter being at fault even though it doesn't get any hotter than normal, no visible water damage, rips, tears, fraying of the cord and the repair is as rock solid as the day it was done.

The only issue, I can find is the voltage output has dropped by 1.1v from the recommended 19v. So maybe the power supplies transformer is on the fritz and there is enough power to charge and turn on the laptop but the laptop power protection circuitry is causing a shutdown to prevent damage to components, that's my theory anyway.

So I'm going to recommend my friend picks up one of those universal power adapters from ebay as they're fairly cheap and I'm not in the mood to crack open the main power supply casing, do further testing and find its nothing that can be fixed anyway especially as I'm doing this gratis.

Thanks,

 

[Vnxc]

If the laptop runs fine on battery, then the power cord is most likely at fault.
Try the universal out and let us know how it goes. Get the right voltage (you are aware of) OME would be best but a universal should work also.