My alpine amp makes a high pitch squeaking sound

[weesatron]

Today when i went to turn on the stereo in my car my sub woofer amp wasn't putting out any sound. So i checked my crossover, curict barker,cables,sub and all that stuff and was all fine so i took it inside to test it with a atx power supply and noticed it was making a hi pitch squeaking sound so disconnected the speaker i was testing it with but the sound was coming out of the amp its self so i open it up to take a look inside cant see any cracked/dry solder joints and nothing looks burnt i just cant figure out why the amp squeaks

so if any of you guys have any idea's what the problem is please let me know

the model number is alpine 3539 if that helps
the area circled in red appears to be where the noise is coming from

[an2ny888]

mine makes the same sound as well, works fine though

[Perry Babin]

The 12v output of many ATX supplies is not regulated. With no significant load on the 5v output, the 12v output may be very noisy and may cause the switching power supply in the amp to produce noise.

You need to troubleshoot the problem in the vehicle if it produced audio on the ATX supply. With a multimeter, you need to check the voltage at the terminals of the amp to confirm that you have ~12v on the B+ and remote terminals (black meter probe on the ground terminal of the amplifier).

[weesatron]

just tried running it off a car battery and it dose the same thing also do you know what components make noise when they fail

[weesatron]

if any one has the curict diagram that would also be helpful

[weesatron]

i just ran a moor thorougher test and found out the right channel works but is distorted and the left dose nothing could it be one of the power transistors?

[lumanauw]

You have to replace the capacitors, especially the 12V input capacitors, like the ones above the green chokes in your pic.
In old alpine amps, these capacitors usually already leaking.

[weesatron]

do you know websites that would sell replacements for the 2 big ones because the local electronics shop dosent sell them

[I Am An Idiot]

Before you go changing parts, I really think you need to find the problem. If you do have an output transistor problem, the amp could be pulling extra current and placing the power supply in a bind, this could cause an audible noise coming from the supply. I would put a 5 amp fuse in the amp and see if it blows that fuse. Power the amp up with whatever fuse you have in it. Turn it off and quickly replace the fuse with a 5 amp fuse, power it back up. If it blows the fuse you have a possible current draw problem. The reason I said quickly was to not allow the capacitors to discharge. If they discharge, it may pull more than 5 amps briefly when powering up.

[weesatron]

ill try that i think it is drawing quite a bit of current because the power cables get abit hot