Infinity 7541 A

mike49504 · 16th April 2011, 04:58 PM

Amp is producing both + - regulated voltages on all op-amps
Its also producing both + - rail voltages (37 volts)

Amp idles perfectly but the problem in having is 3 out of the 4 channels are very distorted. Any ideas on where to begin to look?

Perry Babin · 16th April 2011, 06:59 PM

Can you post a photo of the distorted signal?

Does the position of the crossover switch make a difference?

mike49504 · 16th April 2011, 07:25 PM

Ok i just tryed but now i cant get it to even power up.

Heres what i have on the 494

1:0.55
2:0.41
3:0.17
4:0.51
5:0.05
6:0.53
7:0.55
8:0
9:0.53
10:0.53
11:0
12:0
13:0.44
14:0.42
15:0.42
16:4.68

mike49504 · 16th April 2011, 07:29 PM

Ok I found that problem bad solder connection. I will power it up and post a pic of the output

mike49504 · 16th April 2011, 07:35 PM

Ok i also noticed that one of the power supply fets were missing. Is there a good sub for the FQP50N06?

Perry Babin · 16th April 2011, 07:49 PM

The FQP50N06s are readily available.

mike49504 · 16th April 2011, 08:07 PM

Ok i happen to find some i still had stock of them.

I reflowed the solder on the outputs and bias transistors .

Amp works like a charm..

1 amp down several more to go.

16th April 2011, 04:58 PM	#1
mike49504 diyAudio Member Join Date: Sep 2006	Infinity 7541 A Amp is producing both + - regulated voltages on all op-amps Its also producing both + - rail voltages (37 volts) Amp idles perfectly but the problem in having is 3 out of the 4 channels are very distorted. Any ideas on where to begin to look?

16th April 2011, 06:59 PM	#2
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Can you post a photo of the distorted signal? Does the position of the crossover switch make a difference? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

16th April 2011, 07:49 PM	#6
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	The FQP50N06s are readily available. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
infinity 7541 (my first actual repair attempt).	blakktalon	Car Audio	2	3rd December 2010 10:52 PM
Pioneer DEH-P8600MP, Infinity Kappa 693.5i, and Infinity Reference 6402cfp, and more	jawglasswell	Swap Meet	0	13th March 2005 07:38 PM
Infinity, JBL or other?	ElectroPower	Multi-Way	0	18th December 2004 06:57 PM
infinity reference	spinuz	Multi-Way	0	4th November 2004 02:35 PM
Infinity Sub question	soundNERD	Subwoofers	3	11th January 2004 12:40 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

16th April 2011, 07:25 PM	#3
mike49504 diyAudio Member Join Date: Sep 2006	Ok i just tryed but now i cant get it to even power up. Heres what i have on the 494 1:0.55 2:0.41 3:0.17 4:0.51 5:0.05 6:0.53 7:0.55 8:0 9:0.53 10:0.53 11:0 12:0 13:0.44 14:0.42 15:0.42 16:4.68

16th April 2011, 07:29 PM	#4
mike49504 diyAudio Member Join Date: Sep 2006	Ok I found that problem bad solder connection. I will power it up and post a pic of the output

16th April 2011, 07:35 PM	#5
mike49504 diyAudio Member Join Date: Sep 2006	Ok i also noticed that one of the power supply fets were missing. Is there a good sub for the FQP50N06?

16th April 2011, 08:07 PM	#7
mike49504 diyAudio Member Join Date: Sep 2006	Ok i happen to find some i still had stock of them. I reflowed the solder on the outputs and bias transistors . Amp works like a charm.. 1 amp down several more to go.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read