150.4 starting problem

[Bymcn]

Hello diyaudio family, the problem of the device is that when the plus and minus are connected, the LED light turns red, there is no reaction when the remote is connected, there is no defective part around the TL494, can you help?

 

[Perry Babin]

What output driver ICs are they using?

Does this amp use a microcontroller? If so, what's the number printed on it?

 

[Bymcn]

output drivers irs2092s

 

[Perry Babin]

Does this amp use a microcontroller? If so, what's the number printed on it?

 

[Bymcn]

On the top of the TL494, towards the right, there is an integrated circuit that starts with cd40, but I do not know if it is a micro controller.

 

[Perry Babin]

Starts with? Is it defaced?

Can you post a good quality photo (in focus, no flare, well lit) of the area including that IC and the 494?

 

[Bymcn]

I'm at work right now. When I get home, I'll send you ic's full name and clear photos of 494.

 

[Bymcn]

I would also like to point out that the gray capacitor burst on the Perry output stage, I replaced it, and a 3205 MOSFET was faulty on the feed stage, and even though I installed new ones, when I connected the plus and minus, the red led except the remote started to light up.

 

[Bymcn]

Cd4047bm

 

[Bymcn]

There was a new development. I solved the problem of the red LED that turns on when plus or minus is connected. One 1gm transistor that I missed was found to be defective. It does not light up now, but if I pull the 10kohm resistor connected to the 16th pin of the 494 to GND with tweezers while protecting the device, the device turns on.

While in protection, pin 16 gives 12.69v. If I pull the 10kohm resistor to GND with tweezers, the device turns on.

 

[Perry Babin]

By 'pull', do you mean that you short-circuit across the resistor's terminals with the tweezers?

Do you see read any DC voltage across the speaker terminals of any individual channel when it's not in protect?

 

[Bymcn]

When not in protection, there is no DC voltage on all 4 channels.
Yes, when I bridge the 10kohm resistor connected to pin 16 with tweezers, the device turns on. I left it this way, I collected the device, I use it this way.

 

[Perry Babin]

Are you saying that you bridged the resistor and are going to use the amplifier in that condition?

 

[Bymcn]

Yes, when I do it that way and power it on, the device turns on the protection as before and turns blue. Now I connected it to my vehicle and loaded it, I did not encounter any problems.

 

[Perry Babin]

Do you want to continue to try to troubleshoot or are you going to leave it as is (not recommended)?

 

[Bymcn]

I will leave it this way for now because there doesn't seem to be a problem, the device turns on and off actively. See you for another repair. Thank you Perry for your help.

 

[Perry Babin]

It's risky because it defeats the protection circuit and if an output transistor fails, it could drive full rail voltage to the speakers, causing it to burn the voice coils or cause catastrophic damage to the amplifier.

 

[Bymcn]

After you wrote, I tested it too, I short-circuited the speaker output, the protection circuit is active.

 

[Perry Babin]

OK but you should know that virtually everyone technician working solely on car amplifiers is making a living because protections circuits are notoriously unreliable. Testing the protection circuit in that way can result in amplifier failure.

 

[Bymcn]

Yes, Perry, this is a situation that I have never recommended, but it was a process I did taking the possibility of malfunction, it is not clear what will happen in the future, it was an interesting and different repair for me, the device is currently working with 4 channels active.

If there is a problem with the device, I will contact you again and let you know.
There is a faulty 1700.1 device that I am after, the supply mosfets drivers are good, but even though there are no output mosfets, the LEDs remain flickering while the device is protected. If I get it, I can open a new discussion topic soon and ask for help.