MB Quart RAA2400

mike49504 · 3rd February 2010, 02:52 AM

I worked on this amp awhile back i replaced the power supply section. The amp was working perfect i even showed the customer it was working perfect.

Got the amp back today i dont know what he did but the amp has no output.

Its not producing rail voltage.

Wondering what to check??

mike49504 · 3rd February 2010, 03:52 PM

There is also an op-amp right behind the rca's that is showing voltage for 1 sec then it reads 0 volts on all pins . just wondering where i should start

Perry Babin · 3rd February 2010, 04:54 PM

The power supply is probably shutting down due to an over-current or a DC offset fault in the output section. Is there any DC across either of the channels as the amp tries to power up?

mike49504 · 3rd February 2010, 05:43 PM

no dc output in either channel upon powering it up when i checked it now the amp goes into protection mode.

Perry Babin · 3rd February 2010, 08:50 PM

Does it draw excessive current before going into protect mode?

mike49504 · 4th February 2010, 01:46 AM

no as soon as i hook remote voltage to it it just goes into proctection wont come out of protection mode

mike49504 · 4th February 2010, 06:04 AM

Ok i fixed the protection problem in the amp. Now the amp powers up fine.

Still have no output . I checked the 14 pin ic on the driver board for the outputs and have 0volts on all pins. Wondering if anyone knows what ic this is since its been defaced

Perry Babin · 4th February 2010, 09:49 AM

Can you post a photo of the driver board?

mike49504 · 4th February 2010, 11:39 PM

Ok heres a pic of the output driver board and the main circuit board of the amp without the driver boards in it

Perry Babin · 4th February 2010, 11:47 PM

I'm not sure what the original IC is but an IR2110 worked in an amp (lightning audio amp) with a similar driver board.

Is the amp producing positive and negative regulated and rail voltage?

3rd February 2010, 02:52 AM	#1
mike49504 diyAudio Member Join Date: Sep 2006	MB Quart RAA2400 I worked on this amp awhile back i replaced the power supply section. The amp was working perfect i even showed the customer it was working perfect. Got the amp back today i dont know what he did but the amp has no output. Its not producing rail voltage. Wondering what to check??

3rd February 2010, 04:54 PM	#3
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	The power supply is probably shutting down due to an over-current or a DC offset fault in the output section. Is there any DC across either of the channels as the amp tries to power up? __________________ Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing

3rd February 2010, 08:50 PM	#5
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Does it draw excessive current before going into protect mode? __________________ Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing

4th February 2010, 09:49 AM	#8
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Can you post a photo of the driver board? __________________ Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing

4th February 2010, 11:47 PM	#10
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	I'm not sure what the original IC is but an IR2110 worked in an amp (lightning audio amp) with a similar driver board. Is the amp producing positive and negative regulated and rail voltage? __________________ Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing


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3rd February 2010, 03:52 PM	#2
mike49504 diyAudio Member Join Date: Sep 2006	There is also an op-amp right behind the rca's that is showing voltage for 1 sec then it reads 0 volts on all pins . just wondering where i should start

3rd February 2010, 05:43 PM	#4
mike49504 diyAudio Member Join Date: Sep 2006	no dc output in either channel upon powering it up when i checked it now the amp goes into protection mode.

4th February 2010, 01:46 AM	#6
mike49504 diyAudio Member Join Date: Sep 2006	no as soon as i hook remote voltage to it it just goes into proctection wont come out of protection mode

4th February 2010, 06:04 AM	#7
mike49504 diyAudio Member Join Date: Sep 2006	Ok i fixed the protection problem in the amp. Now the amp powers up fine. Still have no output . I checked the 14 pin ic on the driver board for the outputs and have 0volts on all pins. Wondering if anyone knows what ic this is since its been defaced

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