Orion HCCA5000.1DV2

[caraudioguy2100]

Amp powers up and plays fine .

The problem with the amp is it will play fine then protect them play fone for a day or 2 then protect .

It will sometimes play/protection over and over again .

The guy stated that the amp has been back to Orion 3 times for the issue but they said the amp works correctly .

I can’t get the amp to do this either .

I noticed if I hook the amp up with no rca jacks just power ground remote and speaker I can hear a faint ticking through the test sub .

When I hook the rca jacks up to the amp I get a loud humming through the test sub .

I also noticed I have half a volt of dc measured directly across the speaker terminals and also half half a volt of dc on the rca shield grounds .

Any ideas ?

 

[Perry Babin]

Is the signal source grounded to the same supply as the amp?

Are the shield grounds of the source intact?

What's the DC voltage on the shields of the amp with no RCAs plugged in?

 

[caraudioguy2100]

Signal source is connected to same supply as the amp .

Rca shield grounds are intact inside head unit .

With black probe on amps main ground terminal I get -0.52 volts on the rca shield grounds of the amp

I also get -0.52 volts on all pins of the opamps besides 4 and 8 which are +- 12 volts

 

[caraudioguy2100]

Signal source is connected to same supply as the amp .

Rca shield grounds are intact inside head unit .

With black probe on amps main ground terminal I get -0.52 volts on the rca shield grounds of the amp

 

[caraudioguy2100]

Any ideas what would cause -0.52 volts on the rca shield
Ground and on all pins of the opamps besides 4,8

 

[Perry Babin]

What voltage do you read on the RCA shields using the secondary CT as the reference (black probe)?

Do you see anything other than clean DC on the RCA shields (check with scope)?

 

[caraudioguy2100]

If I use the secondary center tap I still get 0.52 volts on the rca shield ground .

With the scope set to 2 us 5 volts div this is what I get on the rca shield ground

 

[Perry Babin]

Do you see anything like that on the heatsink?

 

[caraudioguy2100]

Yea I get the same thing on the heatsink

 

[Perry Babin]

Using the secondary ground, do you still have -0.52v on the op-amps?

Does the heatsink have any grounds that are missing or broken?

This looks like it's the frequency of the output stage. Is that true?

 

[caraudioguy2100]

Using the secondary center tap as ground reference the voltage goes away on the pins of the opamps .

I noticed 1 opamp has 10 volts on pin 1 while the others remain at 0

And yes it’s the frequency of the output stage in seeing on the rca shield grounds and the heatsink

 

[Perry Babin]

Does the heatsink have any grounds that are missing or broken?

 

[caraudioguy2100]

I couldn’t find any of the grounds missing or broken .


They all seem to be intact

 

[Perry Babin]

Post a photo of the board and the ground points.

 

[caraudioguy2100]

I removed some of the clamps already was gonna pull the board out to check the bottom side of necessary.

This is the only grounding point I see on the board .
Photo 3

 

[Perry Babin]

Is that bussbar next to the screw directly connected to the primary ground?

 

[caraudioguy2100]

No it measures about 1k to ground

 

[Perry Babin]

What does that screw read to the primary ground?

 

[caraudioguy2100]

Meter stays at OL

 

[Perry Babin]

Clamp everything back down and confirm that the waveform is still present on the heatsink. If it is, connect a 1k resistor between the screw and the primary ground. Does that reduce the noise and DC on the heatsink? If so, how much?