Toshiba Laptop reboots with adapter in

Hi,
I have a Toshiba Laptop A200 Which turns off as soon as i plug in the AC/DC adapter. I ran it in safe mode no problem & windows started no problem & it didnt reboot at all & straight away i turned off the power service when windows started & right now as i type i have the AC/DC Adapter plugged In, Charging without laptop re-booting but one downfall, my sound has been disabled. Is that healthy for the laptop??? I took it to Leading Edge Computer shop in Gawler & they said it is a faulty motherboard which cost me $44 & i think they are full of crap cause i dont think they looked at it at all. I took it in on a friday and they said they would look at it on wednesday the earliest which i think i jipped of $44 & they said its going to cost me $847 for a new motherboard. It didnt add up that i needed a new motherboard so i took it to another computer shop & they said it might be a UPS problem which i trust what these people say what might be wrong with it. This problem has definitly puzzled me. Can someone please help me with this situation? It would muchly be appreciated. Thankyou


Thankyou in advanced for your help

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