Audiopipe protection aqx-360.4

Albis2985

Member
2019-06-13 6:45 pm
I took all the outputs and they all measure well the protection is entering through pin16, someone has a scheme since the amplifier sometimes turns on well without any problem and other times it turns on and off immediately the problem is intermittent I don't know what exactly the protection is who is jumping if it is the preamp stage or the amplification stage
 
I don't know how good your camera phone is but you (all here) should look for a good used older model Nikon Coolpix camera. People will give them away. You can buy them for dirt cheap on ebay. They will typically take better photos than the average phone, often due to the better flash and the ability to zoom.
bcae1.com - Car Amplifier Repair Tutorial - The Basics
 

Albis2985

Member
2019-06-13 6:45 pm
If Perry already ordered a camera on eBay, but for now I think that the photos will not be necessary yesterday, I was reviewing and analyzing the circuit a little, I discovered that before the amplifier turned off completely, two outputs gave DC voltage. I removed the transistors from those two outputs and the amplifier turned on well. I have checked the components and they all measure the suspicion of the 649a and 669a polarization transistors, although they are measured well as those of the outputs, I will exchange transistors to see what causes problems and then notify you on the fly
 

Albis2985

Member
2019-06-13 6:45 pm
Good afternoon Perry, the problem with this amplifier is that Q262,263,264 and 265 when turning on the amplifier marks a voltage of more or less 27volts at the base and that is why the amplifier is protected, the damage is intermittent after several times the amplifier works well and the output behaves the same as the others marks a voltage of plus or minus 7 volts in its probe base all the complementary transistors in that section even change the b649 and b669 the problem continues you recommend me to change all the transistors of that output because inside and out of the circuit they measure well even with my tester, or do you think the problem is in the protection part?
 

Albis2985

Member
2019-06-13 6:45 pm
I do not understand exactly your question I attached an image of the stage of the amplifier in question
 

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