Audio output not working after connecting to another audio jack

[HIK141]

Some time ago, I accidentally plugged one end of an audio cable in my laptop's headphone jack, and the other end in a shelf stereo's headphone jack (instead of the shelf stereo's input hole). Then the signals coming from both output jacks seemingly collided, and the laptop's headphone jack stopped working. Now I can only hear small distorted sounds after plugging headphones into the laptop's audio jack. (Laptop's speakers are still working fine.)

Is there anything I can do to fix the audio output jack?
If not, can I use the laptop's input jack as an output hole? I have heard that microphone input jacks can be reversed to work as output jacks; is there an easy way to do this on a Windows 7 laptop?

 

[veltliner]

You won`t be able to use the input jack as output.
I think your headphones are broken, that seems to be the only logical explanation. Have you tried pluggin in another pair?

 

[HIK141]

You won`t be able to use the input jack as output.
I think your headphones are broken, that seems to be the only logical explanation. Have you tried pluggin in another pair?

It probably isn't headphones fault, because I have tried to connect other headphones, as well as some earphones and the same shelf stereo, but nothing worked. Just occasional distorted sounds can be heard when the output volume is turned up. So I'm pretty sure that the laptop's audio output is damaged.

There actually are some ways to reverse the input jack, but I'm not so advanced in technologies to do that Plus my laptop is *really* old, so that probably wouldn't be possible here