Brutus BXI2006

dartssport · 2013-08-14 2:31 am

Got a Brutus BXI2006 (Hi Fonics) with blown power supply and shorted outputs.

If in getting 12v and 3.3v at the pads(power supply) do I still need to replace the driver trannies?
If so are these located in Q07 and Q08? there appears to be 2 of each, Im assuming 1 set for each back.

I also noticed this amp uses all IRF640's with no 9640's

From reading the other posts about this amp I can use IRF3205's instead of the DFP units.

Perry Babin · 2013-08-14 2:44 am

3.3v seems low. What's the voltage on pins 9 and 10 of the KA7500 IC?

Q7, Q8, Q7A and Q8A are the driver transistors for the power supply FETs.

dartssport · 2013-08-15 5:17 pm

Ok Im getting 4.44v on the KA7500 so I will have to change the driver transitors.
Is there anything else that could cause the drop in voltage?

Perry Babin · 2013-08-15 11:49 pm

Order the BD139 and the BD140 for the drivers.

The MMBTA42s and MMBTA92s on the audio driver board sometimes fail.

dartssport · 2013-08-30 1:44 am

I have the BD139's and BD140's still waiting on then outputs, the BD's are a different package type so do you mount them with the numbers facing the same way as the originals? or do i have to turn them around?

Also purchased a BK 2120 scope now i just need a waveform to test.

Perry Babin · 2013-08-30 1:55 am

They face the same direction.

Index of /temp/test tones

dartssport · 2013-09-09 10:01 pm

Well finally got all the new parts installed and hook it up and soon as the relay clicks i get a noise coming through the speaker that is kinda hard to describe, its a steady noise with a little white noise in it. any ideas?

Perry Babin · 2013-09-09 10:24 pm

Do you get noise with no RCAs plugged in?

What is the rail voltage in the amp?

dartssport · 2013-09-10 12:55 am

No I had audio playing through into it.

Where would I place the probes to measure rail voltage?

Perry Babin · 2013-09-10 1:42 am

To clarify... With no RCAs plugged in, there is no noise?

You can check the rail voltage on the metal tabs of D32 and D33.

dartssport · 2013-09-10 2:18 am

confirm with no RCAs attached the noise still exist.

there are no metal tabs on D32 and D33 they appear to be all silicone construction.

dartssport · 2013-09-10 2:32 am

Im getting 59 and -59 volts at the outer legs or d32 and d33

Perry Babin · 2013-09-10 3:05 am

Confirm that you have positive and negative 15v on the power supply pins of all of the op-amps.

dartssport · 2013-09-10 7:05 pm

Would that be the KA7500 or LM293? or another location?

Perry Babin · 2013-09-10 10:13 pm

IC101, 104, 109... in the preamp section of the amp.

dartssport · 2013-09-10 11:37 pm

IC101,102,103,105,106,107,110 all have 15v and -15v.

dartssport · 2013-09-11 12:01 am

One probe grounded and one on the clips of the FETs displays 58+/- volts is this typical or could one of the FETS be touching the clip?

dartssport · 2013-09-11 12:28 am

Ok no more voltage to ground and the noise is gone but still no output on the speaker terminals.
Vertical board near preamp side its getting pretty hot

dartssport · 2013-09-11 5:06 am

Ive not been able to local IC104 and IC109.
Im also finding ac voltage on the speaker outputs.
Is this supposed to happen?

Perry Babin · 2013-09-11 5:59 am

Audio is AC voltage.

Post a photo of the board in this amp.

Did the relay engage?

Brutus BXI2006

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