Teac amp h300 mk 11

I switched my system on this morning and all I could hear was a loud "knocking noise" coming out of the speakers.

The music was still playing but the knocking was overpowering!
i have tried the system with another amp and it is fine so i know the amp is at fault.

I am suspecting either some liquid has been spilled into it by my kids and have sprayed with wd 40 and it seems slightly less noisier. i also noticed that some of the spkr wire was punctured by the carpet gripper and have replaced.

Can anyone tell me if these two things would cause such a noise / fault or is it anything else.

Thanks in advance.

[Cable Monkey]

If you suspect fluid then don't spray anything in it, just put it somewhere warm for 48 hours to dry out. If the speaker cable is suspect replace all of it. If these options both fail the damage is permanent.