Back around March I bought a Crate Flexwave 120h amp head. After researching these amps I knew they had problems but I tested this one and it worked fine. I bought it from GC for $110. About a day after I took it home the reverb was stuck on 10 so i took it back and the GC tech fixed it for free. After he turned it off none of the effects ever worked. I was not able to get a refund. About 2 months ago it started to get really quiet. I had this amp on like half volume and it barely made sound, just fading in and out. Now it takes like 15 minutes to get this amp to put out any normal level of sound and even when it does sometimes theres hardly any gain. Is my amp dying or can I fix this?  Any advice is much appreciated. Thanks for reading.
If you really want to fix it, you'll have to take it to an amp repair shop where they actually know what they're doing (Guitar Center most definitely does not).

The bad news is it will most likely cost you more than the amp is worth. If you want a good solid state head on the cheap, take a look at the Randall RG series. Going back to the RG100es (can be found on the used market wuite often), which is an absolute legend of an amp (it's what Dimebag used on the first few albums), to their latest RG amps, which are damn good amps for the price.