Hi mbefkadu,
This sounds to me like a power supply problem. Are you using just the amplifier built in to your CD player, or are you using a separate external amplifier?
What you describe sounds like something that is more common when using an external amplifier, but could happen if it is just the CD player.
Basically I think that not enough power supply is reaching your CDX-GT25. One possible explanation is that your car battery is low on charge - under these conditions what happens is that your stereo is OK up to a point, but as you increase volume you reach a point where the battery hasn't enough power to run the unit at this level - so it switches off. The battery then recovers very slightly (as the demand upon it has gone) and power to the unit is restored and it switches back on - but if the volume level is still high, almost straight away the power demand is enough to switch the unit back off again ..... so you go round in circles with the unit/audio switching on and off repetitively until you turn the volume down to a point that the battery is able to delivery enough power to unit to keep it switched on consistently.
Hope that makes sense - but I would say it's worth getting the battery checked out, and if it is OK having an in-car specialist installer to check that the power supply connections in your car are up to the job.
Hope you get sorted!
