Hifonics BXI-6000D

[Achim1409]

Hello, i received a broken BXI-6000D for repair. Problem here, one Bank of output Fet´s are blown because of some broken legs on that Fet´s. On the Backside some lanes are burned. I removed the Fets and repaired the lanes. Without the Fet´s, the amp is shortly power amp, and then off again. Also the relay´s sounds very weak when they clicking. If pictures needed i can make some. Can anybody give me an advice or supply an Diagram?


Regards
Achim

 

[Perry Babin]

Photos of the main board and driver boards?

 

[Achim1409]

Replaced all damaged parts. Amp is powering up, LED is green, Rail Voltage is ok, but the relay´s not clicking. Got no power on that relay´s. If i measure from Battery Minus to the relay i measure +12V, but if i measure direct on both connections on the relay there is nothing. Also no clicking. Checked the Voltage´s on the audio drive board, all voltages ok.

 

[Perry Babin]

Do you have a scope?

 

[Achim1409]

Yes

 

[Perry Babin]

Do you have clean audio (with no significant DC voltage) at the input to the relays?

 

[Achim1409]

i can give with my cellphone a 50hz Signal into the amp and check with the scope.

 

[Achim1409]

Here some Pics.

 

[Perry Babin]

What are the photos showing?

Without having the scope reference centered and set to DC coupling, I can't tell what they show.

 

[Achim1409]

It seems that i have 110VDC on the output before the relay. If i disconect the Oscilloscope the line is in center.

 

[Perry Babin]

In the photos, the original ICs are still on the driver board. Did you replace them after the photos were taken?

The ICs almost always fail when the outputs fail.

Allow the rail caps to discharge and check the two driver ICs as shown in the attached image.

 

[Achim1409]

No, still The Originals. I will test tomorrow.

 

[Achim1409]

I have checked the drivers, all values above 3,7kOhm. Should be still ok.

 

[Perry Babin]

Are all of the voltages marked for the driver board correct?

 

[Achim1409]

yes. all Voltages according to the marking on the mainboard for the drive board in range.

 

[Perry Babin]

Let all caps fully discharge and solder a bridge between pins 2 and 3 of the two driver ICs.

Does the amp power up and the relays engage?

If so, do you read 0v DC across the speaker terminals?

 

[Achim1409]

Soldered the Bridge, Amp powers up. Relay clicking, but directly the relay disengaged .After the second try powering up with remote, there was no more clicking at all. Green LED still on, current 1,5Amps. Before i put the solder bridge, when the amp powers up, i heard a hissing sound from the output inductors ( sounds like charging the capacitors, because the frequency of the noise rise until its gone)

 

[Perry Babin]

Do you have DC voltage on the output filter inductors before the relays?

 

[Achim1409]

yes, 73V DC.

 

[Achim1409]

Found, that on one side i have a drive signal, on the other side nothing. Changed the driver with in 21844s. But still no drive signal on that side. Removed the solder bridge also.