2 months ago I had an amplifier faulty and I tried to repair it. After checking found maybe the transformer of the Amp damaged due to power surge or lighning. I bought a new transformer and replaced to the amp and tested working fine.
With that I save some money to buy a new amp. For those having amp faulty, may try to repair it so can save some money instead of buying a new amp as sometime the amp just having some mirror problem that can be repaired with just 10-20% of the new amp price.
For those that having expensive amplifier, I do advise to install an power regulator to protect them.