Chevy Radio Problems

I have a 2001 Tahoe, and have had problems with the clock on the radio going to 12:00 and the radio going off between start ups. I have taken it in 3-4 times since purchasing and no one could figure it out until today. Last year when I took it in for this, they replaced the battery. Today I am being told it is an "internal" problem with the radio, and of course the only way to fix it is replacing the whole radio.

Has anyone else had a similar problem, or have any suggestions?

I am very angry because now it is out of the regular warranty, and I get to pay a $200 deductable to replace the radio with the extended warranty.

Don't know if this is the same problem, but every so often the radio in my 01' Silverado Z71 will lock out for no reason (only supposed to if the power is disconnected from it). Was told it was a malfunction in the radio, and I could have it reconditioned or replaced. Problem is, they want more than a new Kenwood, Pioneer, Alpine, Sony etc... I am just waiting for it to crap out all together and put in a good one.

Don't know if this is the same problem, but every so often the radio in my 01' Silverado Z71 will lock out for no reason (only supposed to if the power is disconnected from it). Was told it was a malfunction in the radio, and I could have it reconditioned or replaced. Problem is, they want more than a new Kenwood, Pioneer, Alpine, Sony etc... I am just waiting for it to crap out all together and put in a good one.

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When it locks out, how do you unlock it? I bought the Tahoe used and I have no idea what the security code is? I'm sure the dealer will provide it, but I bet it will cost me big bucks at the service department!