Clarion DPX11500 #2 Repair

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I couldn't really get it to lock in well... maybe wrong settings. We have noted that Q1 and Q32 they are (TIP107 & TIP102) are getting hot very quickly.
 

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The TIP102/7 are being used as regulators so it's normal for them to get hot. Don't let them overheat. If they do and short, they could do extensive damage.

The signal is noisy but that doesn't necessarily mean it's going to sound distorted. Does it sound distorted?

Set the vertical amp to 10v/div and drive the output so that it fills the display vertically.

If you set the trigger to HF reject, it should lock better.
 
Hi Perry,

I have since went and picked up the amp, Paul has been quite busy, and I couldn't expect him to drop everything for my amp when it was pro bono.

Paul advised there isn't any way for me to accurately test the .1 ohm resistors as you need more than a regular dmm to accurately do so. He also mentioned that this was a possibility that one of the 2W .1ohm resistors on the output transistors could be defective, so based on the low cost of the parts, ($.05 each) I opted to replace the twelve of them. This did not change the output using my ipod.

Paul advised when I was visiting him that it could be because the source was not connected to a source with a ground that was common to the amplifier. I took the amp out to the car and carefully tested with the RCA's coming off of the head unit in the car. Same problem as before.
 
*EDIT* Ok.. I'm back from reading page 1.. lol.

You stated at first that you had this voltage with the outputs OUT of the circuit and nothing changed when they went back IN. I have never touched this amplifier, so this is speculation on my end next.

There is not a whole lot going on in between the output terminals and the output transistors that could introduce a voltage all by itself. So if you yank the output transistors completely out of circuit and get that voltage on the outputs you don't have a very large area to look at. I would start looking for post output components with access to a voltage source (Ie, active parts, not passive) and/or any sort of components part of the feedback system. Perry might have a partial schematic to help.
 
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I have the service manual, complete with schematics.

This DC voltage that I have, continues to fall the longer the amplifier is turned on. Since I have been testing with the board out of the sink, I have not let this go too long as the Tip 102/107 get extremely hot and I do not want them to fail.

Perry:

Paul did not have a chance to get his source hooked up. So i picked the amp up and tested it hooked up to my head unit in the car, amplifier connected to the same power supply as the deck, and the same amount/type of distortion is present.

Prior to this, I had been using an MP3 played from my cell phone.

Prior to this all testing had been done from my ipod (music for example)
 
Nevermind, found it online..

If it's really beating everybody up, Here's a brute force process of elimination:

Pull all the main output emitter resistors out on one end to disconnect them from the output without pulling the drivers themselves. Confirm you still have your voltage on the output terminals (do NOT use a source for these tests). If it's there, proceed, if not post back. For clarification you are going to watch the voltage from the speaker output terminals at all times.

1) Lift one leg of d14 then d23 at a time. - Voltage still on the outputs? Yes = proceed (if measurement changes, post it)
2) Lift one leg of r7 & r145 at a time. - Voltage still on the outputs? Yes = proceed (if measurement changes, post it)
3) Lift one leg of r4 & r151 at a time. - Voltage still on the outputs? Yes = proceed (if measurement changes, post it)

At this point, if you still have something it could be sourced at the feedback front end.

4) Lift one leg of r40, r48 & c16 at the same time. - Voltage still on the outputs? Yes = proceed (if measurement changes, post it)

There are other ways to do this, but it seems like you and your friend are at your wits end. At this point, just start pin disconnecting sections of the circuit with any ties to the output till you see a change. Then go from there. You do a lot less desoldering this way too. I would follow it around with a DMM myself, but that doesn't seem to be going well for you.
 
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So disconnect one leg of each .1ohm resistor from the board and start at step one. I'll give it a try. I have no problem tracing circuits around the board with my DMM, but I do not really know what I am looking for when I do. I can take measurements and post them, but not unless I know what to look for in the first place.

I'll give what you have suggested a try and report back.

Thank you
 
Ok, but you got that far without a rise or loss of the original output?

If so, put all legs back in. You have a leak or open somewhere in the drive section. I'll maul it over for further instructions or Perry can jump back in. I got nachos I don't want to get soggy here :)
 
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