mtx 895 amplifier testing and repair

I have recently had problems with my amplifier. This is a 5 channel amp. The front 4 channels work fine. The sub channel however has stopped working. If the gain is turned all the way up sound is produced but it is not accurate. At other times the subs just burp every now and then with or without a signal present. I have taken the amp out and have taken the cover off. I would like to repair this amp myself if possible. However, I'm not sure what to test or how to test it. Any advice or suggested websites would be great. Thank you

First of all, an amplifier's gain should NEVER, I repeat NEVER be "turned all the way up."  You need to learn how to set your gain or have it done by a pro.  If you have been cranking your gain you could very easily have blown the sub amp channel in this amplifier.  You need to take it to an authorized repair location and have it tested and repaired.  Then learn how to set gains and do it correctly and LEAVE THE GAIN ALONE.Support the12volt.com

The gain was not all the way up before the channel stopped working. I do know how to set up an amplifier. In 12 years this is the first time I've ever had anything like this happen. What I'm saying is that turning the gain all the way up is the only way to get sound out of it after the problem. I thought that may make it easier to diagnose. I'm not planning on taking the amplifier to a repair center. I've already gotten another amp to replace it. I plan to repair the amplifier myself. I consider myself fairly proficient with circuits having installed remote starts and various electronics for years, but this is a little new to me. I'm just trying to find a way to properly diagnose the problem so I don't have to spend weeks testing every semiconductor in this thing, as there are a lot. Thank you

Here's a very recent thread regarding this very question... After you read it,you might see that DYohn is right. Personally, I am NOT trying to discourage you - I think everybody should know how to do SOME basic repairs, but a little bit of first-hand knowledge can be helpful. The circuitry can be a bit daunting, but take a look at it, AFTER you read this link...It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

First check to see if the rca input on the sub channel is still actually connected to the board. My experience with older mtx amps is that they come unsoldered. If you've never fixed one before, be careful you could possibly just end up messing up the amp.