Hifonics Brutus BXi1100D mk2 no audio

[Mote]

I still have very little experience with class D amps so I will rather ask what to do than blow this amp doing something stupid.
Amp draws about 2,3A of current which I suppose is normal considering the LED show on the heatsink and amplifier size.
There is no DC voltage between speaker terminals, no increased current draw when speaker is connected. I think that is because the relay does not click .
Voltage between GND and speaker + is 33V I do not know if that is normal.
Relay is SLA-12VDC-SL-A.
Pinout can be found here:
Buy relay, T90, PCB relay, 25pcs DC12V Electrical Mini PCB Type Power Relay SLA-12VDC-SL-A (T90) 5pin at Aliexpress.com
Coil pins are on left top and bottom one? On those pins amp has 11V, so relay can not function?
Amps Protection LED is not lighted, only Power LED.
Transistors seem fine, no shorted ones when testing on board. Power supply FETs have 3,4V on their gates. Rail voltage is 42V and present on output transistors.

What to check next, waveforms and voltages on HIP4080?

 

[timwebb]

U got a picture? Im thinking for the relay it could be a diode near it gone bad. And the hip4080 has most likely. Failed too.they always do. Also the output. Transistors will fail and not trip the protection. So check them out of circuit before buying a new ic and installing it.

 

[Perry Babin]

Do you see any audio on either speaker terminal (no speaker connected) when you drive signal into the amp?

 

[Mote]

Perry:
No audio on speaker terminals.

Timwebb:
Will post photos afterwards. Outputs seem OK, what voltages I should read on output transistors in a working amp?
In my amp I get 4 different results for 8 transistors:
1:37
2:48
3:34

1:1
2:34
3:-0,3

1:15
2:45
3:11

1:7
2:12
3:0,3

Only diode which I see near relay is one of RP diodes, connected between GND and B+.

 

[Perry Babin]

What DC voltage to you have on pins 5, 6 and 7 of the 4080?

 

[Mote]

5: 2,6
6: 10,2
7: 11,7

 

[Perry Babin]

If it has a ZD1, it's defective. It's a 6.2v Zener.

 

[Mote]

It has DZ1, 1N4744A 15V Zener, appears to be in working order, has 15V across its terminals.
Near 4080 there is a DZ3 with 7V across its legs.

 

[Perry Babin]

In other 4080 based amps, the Zener is used to bias the audio to about 6v. That will show up on pins 6 and 7. The Zeners often fail and allow the voltage to go significantly higher. When you post a photo of the area around the 4080, I may be able to offer more specific suggestions.

 

[Mote]

Here you go.

 

[Perry Babin]

Post the DC voltage on all pins of U10.

 

[timwebb]

the 1600 im working on is the same. dz3 is cooked on mine

 

[Mote]

Im not so lucky, my DZ3 looks good.
Will post voltages on U10 when I get home from work.

 

[Mote]

U10
1:6,44
2:6,54
3:6,54
4:-0,51
5:7,26
6:7,28
7:6,60
8:11,77

 

[Perry Babin]

Post the voltage on U9 and confirm that the voltages on pins 5, 6 and 7 of the 4080 are approximately the same as they were.

 

[Mote]

U9
1:11,62
2:6,57
3:11,59
4:-0,51
5:6,54
6:6,27
7:6,28
8:11,79

4080
5: 5,6
6: 6,1
7: 6,6

I am measuring voltages with black probe on GND terminal, is this correct?

 

[Perry Babin]

The voltage on 5, 6 and 7 are much closer to normal. Did you do anything to the amp?

Yes. Black probe on the amp ground.

 

[Mote]

I only removed DZ1 to check and put it back, other than that I did not do anything, but there is still no audio.

 

[Perry Babin]

Previously, you had about 11v on 6 and 7. Did you look for audio on the speaker terminals with no load to see if there was any audio?

 

[Mote]

Yes, I realise that there is a change in voltages, pins 6 and 7 of the HIP which previously had excessive 11V now have 6V. I checked for audio on speaker terminals with scope, without speaker attached did not have any before do not have any now. I did not do anything (at least intentionally) to amp that could have caused the voltage to drop.

I believe that relay is not engaging so there can not be any audio on speaker terminals, maybe I should search for audio on relay terminals?

Also I noticed now that outputs are getting hot even without any signal going to amp, is this normal (board is out of the sink).

Is the -0,15V on U9 and U10 normal, should not they have something more closer to -15V, DZ1 and DZ2 seem to be 15V Zeners in charge of giving -/+15V to opamps, maybe I did a bad job reinstalling DZ1 and ICs are not getting -15V now?