Thanks for your reply.
Since yesterday this amp. started working Ok again, I really don`t know what happened. This week-end I will be using in during the Carnival parade, which means five to six hours none stop music, at full power. This same problem I noticed on an old Ma-2400 (8 years old), that I use only twice or three times a year. When i powered it up, it took some time for the ODEP (red lights) to come on. then i thought it was Ok, but when powering up the next day, it seemed like a relay or so on one of the channel was going crazy, because the IOC light started going on and off, and the ODEP light went out. I opened up the amp. used an air compressor to blow it clean, and today when I turned it on, it was working normal again. This amp. will be in the parades to, let`s hope for the best.