Hello All,
First post, and I'll do my best not to sound like a newb.
I've been reading quite a bit between this site and others online. Great resource for finding information about parts.
I have a Clarion DPX11500 amplifier that I bought for $50. I knew I was buying a dead amp. From my observation it was over driven with a poor ground which caused it to get hot enough to melt insulation. Various heat damage to components in various locations on the board. The ribbon cable going to the RCA board was actually charred as in fire damage.
Power supply was damaged, replaced all eight HUF75344G3 fets, as well as the 5.11ohm gate resistors.
This stabilized the amp enough to connect a fused power supply.
I have the service manual here, and have replaced a few parts that were visibly damaged. There are a dozen or so resistors on the board that are browned, but still measure fine. Others, not so much which I replaced. Same with diodes. There were a couple that were badly discoloured which I replaced. I replaced the ribbon cable.
I do have a knowledgable friend that has been helping me with random questions, but I was hoping there may be some specific questions that you guys could answer.
Has anybody here successfully repaired one of these?
What voltages did you read on your ic KA3525A?
I suppose this is more complicated than other repairs I have done due to a PIC18F1220-I/P processor which I haven't been able to find concrete information on as well.
I have seen a mention of a protection circuit tutorial. Where do I find it?
I originally posted this under solid state which isn't where it should have been. My apologies for cross posting it here.
First post, and I'll do my best not to sound like a newb.
I've been reading quite a bit between this site and others online. Great resource for finding information about parts.
I have a Clarion DPX11500 amplifier that I bought for $50. I knew I was buying a dead amp. From my observation it was over driven with a poor ground which caused it to get hot enough to melt insulation. Various heat damage to components in various locations on the board. The ribbon cable going to the RCA board was actually charred as in fire damage.
Power supply was damaged, replaced all eight HUF75344G3 fets, as well as the 5.11ohm gate resistors.
This stabilized the amp enough to connect a fused power supply.
I have the service manual here, and have replaced a few parts that were visibly damaged. There are a dozen or so resistors on the board that are browned, but still measure fine. Others, not so much which I replaced. Same with diodes. There were a couple that were badly discoloured which I replaced. I replaced the ribbon cable.
I do have a knowledgable friend that has been helping me with random questions, but I was hoping there may be some specific questions that you guys could answer.
Has anybody here successfully repaired one of these?
What voltages did you read on your ic KA3525A?
I suppose this is more complicated than other repairs I have done due to a PIC18F1220-I/P processor which I haven't been able to find concrete information on as well.
I have seen a mention of a protection circuit tutorial. Where do I find it?
I originally posted this under solid state which isn't where it should have been. My apologies for cross posting it here.
The 3525 can function with a wide range of voltages. Is your amp producing rail voltage?
If not, you may need to post the voltage on yours.
The protection circuit troubleshooting page was likely a reference to a section of the repair tutorial that I sell. It doesn't cover the PIC in this amp.
The PIC controllers are programmable so they vary in how they operate. If the owner's manual doesn't provide the information that you need, the only meaningful information you're likely to find is regarding the power and ground connections. These ICs VERY rarely fail.
If not, you may need to post the voltage on yours.
The protection circuit troubleshooting page was likely a reference to a section of the repair tutorial that I sell. It doesn't cover the PIC in this amp.
The PIC controllers are programmable so they vary in how they operate. If the owner's manual doesn't provide the information that you need, the only meaningful information you're likely to find is regarding the power and ground connections. These ICs VERY rarely fail.
Hi Perry, thanks for the reply.
No rail voltage. I get -12.5V on each rail
KA3525A
1) 0
2.).34
3).01
4).01
5).01
6).01
7).01
8).08 which dropped to .03
9).34
10)0
11)0
12)0
13)12.51
14).37 dropped to .01
15)12.51
16).34
Negative rail -12.31
Positive rail -12.31
Tip 102 and Tip 107 both read 12.51
On my protection board:
LM393 only have voltage on pin 4 and it is .4
There are two PC817, I get 5.37 on pin two of the first one. The second pin 2 is 4.21
There is a TL072, voltage only on pin 4 .4V
I also have the voltages for the pic processor,.
No rail voltage. I get -12.5V on each rail
KA3525A
1) 0
2.).34
3).01
4).01
5).01
6).01
7).01
8).08 which dropped to .03
9).34
10)0
11)0
12)0
13)12.51
14).37 dropped to .01
15)12.51
16).34
Negative rail -12.31
Positive rail -12.31
Tip 102 and Tip 107 both read 12.51
On my protection board:
LM393 only have voltage on pin 4 and it is .4
There are two PC817, I get 5.37 on pin two of the first one. The second pin 2 is 4.21
There is a TL072, voltage only on pin 4 .4V
I also have the voltages for the pic processor,.
Thank you for the advice.
I went ahead and replace the IC.
I have the following voltages.
1)0
2.).42
3).01
4).01
5).04
6) 0
7) .04
8).21
9).42
10)0
11)0
12)0
13)12.42
14) 0
15) 12.42
16) .42
Which pin should have 5.1V on it? I am not sure what happened, but when I originally tested last week I thought I recalled having 5.1V on one of the pins.
I went ahead and replace the IC.
I have the following voltages.
1)0
2.).42
3).01
4).01
5).04
6) 0
7) .04
8).21
9).42
10)0
11)0
12)0
13)12.42
14) 0
15) 12.42
16) .42
Which pin should have 5.1V on it? I am not sure what happened, but when I originally tested last week I thought I recalled having 5.1V on one of the pins.
Ok, so after tracing circuits and testing components I decided I would try installing another new KA3525A.
Sure enough, it turns out that the new one I recently installed was in fact defective.
I get the following numbers now:
1).01
2.)5.04
3).04
4).12
5)2.09
6)3.68
7)2.09
8)4.8
9)0
10)0
11)2.75 (this one was going up)
12)0
13)12.09
14)2.75 (this one was climbing as well)
15)12.09
16)5.06
Much different than the old one.
I started testing rail voltage.
On the positive rail I measured 15.45V testing from the transformer to the centre pin.
When trying to test the negative rail, I didn't touch anything but the contact on the transformer and the centre pin, but the amp when into a fault and overloaded the test speaker with enough power to damage it before I realized there was a problem... Good thing for fuses. This behaviour keeps repeating. I gave up trying to test the negative rail. I did see 16V initially before the fault started.
Sure enough, it turns out that the new one I recently installed was in fact defective.
I get the following numbers now:
1).01
2.)5.04
3).04
4).12
5)2.09
6)3.68
7)2.09
8)4.8
9)0
10)0
11)2.75 (this one was going up)
12)0
13)12.09
14)2.75 (this one was climbing as well)
15)12.09
16)5.06
Much different than the old one.
I started testing rail voltage.
On the positive rail I measured 15.45V testing from the transformer to the centre pin.
When trying to test the negative rail, I didn't touch anything but the contact on the transformer and the centre pin, but the amp when into a fault and overloaded the test speaker with enough power to damage it before I realized there was a problem... Good thing for fuses. This behaviour keeps repeating. I gave up trying to test the negative rail. I did see 16V initially before the fault started.
Okay, so I got home from work and took another look at the amp. I do not see any solder bridges that could be shorting it out, however I will take a more indepth look later.
I pulled the rectifier diodes, they all check out as being ok.
I hooked my meter leads up to the speaker output to measure for DC voltage.
Knowing this had to be a quick operation, I watched carefully.
As soon as I touch the remote wire to 12V to turn the amp on the DC voltage jumped up to 18V. This is before the amplifier turn on light had even been lit.
This problem appears to have started when I began testing the negative rail for voltage.
I suppose I'll start pulling the out puts on this rail to see if there is a short.
I pulled the rectifier diodes, they all check out as being ok.
I hooked my meter leads up to the speaker output to measure for DC voltage.
Knowing this had to be a quick operation, I watched carefully.
As soon as I touch the remote wire to 12V to turn the amp on the DC voltage jumped up to 18V. This is before the amplifier turn on light had even been lit.
This problem appears to have started when I began testing the negative rail for voltage.
I suppose I'll start pulling the out puts on this rail to see if there is a short.
Here's a couple of leads but don't know if these are the package type you need.
Find 2N6726 Stock and Compare Prices Across the Most Reputable Distributors in the Industry.
Find 2N6726 Stock and Compare Prices Across the Most Reputable Distributors in the Industry.
Hi Perry,
Those parts won't fit. The original is a T0-237 case. Looking at those, it appears they are larger.
How do I test my output transistors? They are 2SC3263 and 2SA1294
I have a new one to compare values to, on diode test I get a reading of 487 on the outer pins of the new one. Doing the same with the ones which are installed, I get a the same readings on only one of them. Of seven transistors, I get a reading of 23 on six of them on the outer pins.
Those parts won't fit. The original is a T0-237 case. Looking at those, it appears they are larger.
How do I test my output transistors? They are 2SC3263 and 2SA1294
I have a new one to compare values to, on diode test I get a reading of 487 on the outer pins of the new one. Doing the same with the ones which are installed, I get a the same readings on only one of them. Of seven transistors, I get a reading of 23 on six of them on the outer pins.
Hi Perry,
The location that these two transistors occupy is quite tight.
Anyways,
I have acquired another amplifier that is blown, same make.
This is in much better repair than the last. I powered it up with the head light in series, and it turns on then off and the protect light flashes. (more than the other would do)
I pulled the outputs off one side of the board, (negative rail I believe) and it would power on, and the power light would stay lit. However I still had 1.2V of DC voltage on speaker out.
I pulled the outputs off the positive rail, and the DC is still there on speaker out, except I notice it drops from 1.2 down to about .98 after 10-20 seconds of being on.
I have tested the outputs, but I have a meter that is really inexpensive, and diode testing gives me a reading of 487 on the old ones, as well as on brand new control sample. There is no decimal reading. So according to that, all the outputs are fine. However I have no way of knowing based on 487, when there is supposed to be a reading on diode test of .6V.
Whats the next step?
The location that these two transistors occupy is quite tight.
Anyways,
I have acquired another amplifier that is blown, same make.
This is in much better repair than the last. I powered it up with the head light in series, and it turns on then off and the protect light flashes. (more than the other would do)
I pulled the outputs off one side of the board, (negative rail I believe) and it would power on, and the power light would stay lit. However I still had 1.2V of DC voltage on speaker out.
I pulled the outputs off the positive rail, and the DC is still there on speaker out, except I notice it drops from 1.2 down to about .98 after 10-20 seconds of being on.
I have tested the outputs, but I have a meter that is really inexpensive, and diode testing gives me a reading of 487 on the old ones, as well as on brand new control sample. There is no decimal reading. So according to that, all the outputs are fine. However I have no way of knowing based on 487, when there is supposed to be a reading on diode test of .6V.
Whats the next step?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.