electrical issue?

Greetings all,
Been having a recent problem with my 2004 Allroad. When the car is off and out in the cold (-15 to -20C) for a few hours), when I turn on the radio, I
can see it comes on, but no sound from speakers. Once its back into my garage (where the temperature is about 2C-7C) overnight, the radio and speakers are back to normal the next day. Any thoughts on what could be wrong?
John
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crack in a circuit board track.....when it contracts the track parts.
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Would this circuit board track be in the radio itself, or elsewhere?
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most probably in the radio...........may also be a soldered (dry) joint somewhere in radio.
I believe some manufacturers are using 'green solder' ie lead free and this could be the problem.
It is rather odd that when delving deep into electronics goods specifications many actually state, only operate at 0-30C.................
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Thank-you for your advice. Am taking it to my dealership next week (as the vehicle is under waranty still). Problem is....I was told that the tech needs to witness the problem. I'm leaving it overnight at the dealer's in hopes that it will be demonstrated in the morning. I hope its really cold........
John
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Often it's caused by bolting power semiconductors to heat sink fins on the chassis. Vibration and thermal stress eventually cracks the solder or even the circuit board. Better designs use a spring clip so that the component can slide under high stress.
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