I have a 600.2 in front of me, the circuit is not the same.
http://diymobileaudio.com/gallery/watermark.php?file=8559
Wish it were. The rectifier diodes aren't even there, it is not the same. The A600 uses two rectifiers on the Q1 the 600.2 doesn't even HAVE both rectifiers on it unfortunately. (one)
http://diymobileaudio.com/gallery/watermark.php?file=8559
Wish it were. The rectifier diodes aren't even there, it is not the same. The A600 uses two rectifiers on the Q1 the 600.2 doesn't even HAVE both rectifiers on it unfortunately. (one)
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The transistor in your picture is a 2n6488 in the a600.2/2n6487 in yours, used as a voltage regulator from what I can tell. It is the same as Q6 in the a600.2. The a600.2 uses seperate diodes in the power supply to increase heat dissipation capability of the rectifiers for better reliablity/more current capability.
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Well what I have is a dead A600 😀 I just don't understand why it is arcing and I wanna make it stop. 😀
If there was excessive heat, the board may have become conductive. If that's the case, the carbonized board will have to be cut away until you reach clean fiberglass. You're the only one who can see it well enough to know if that's what has happened.
If traces have to be cut to remove the damaged board, you'll have to reestablish the connections with jumpers.
If traces have to be cut to remove the damaged board, you'll have to reestablish the connections with jumpers.
Thank you (both of you), I did indeed scrape away a lot of black, but I couldn't tell if it were burnt fiberglass or what. All I know for certain is that I have a valley between the two holes now. 🙂 I had no metered resistance between them so not dead shorts, but the carbon would cause a lot of trouble if it were there. I suppose it is time to try again now, but I won't exactly get my hopes up yet. It still messes with me that it was doing fine and just started arching while playing - fully put together. Of course we knew it already had signs of heat so something had been going on at some point leading to this.
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Ha haaha I quit. Now it's arching on the other side on the transistor I said was getting hot to begin with. Without you re-reading Q33 was the trouble maker that was getting smoking hot and I was getting popping in the amp through the speaker. I replaced it, Q1 starts arching. I scrape Q1 bone dry..... Q33 is now arching. I can clearly see these two are partners in crime.
After scraping the carbon off Q1 and trying again, Q33 was now arching. I figure that was what started this whole mess to being with. After cleaning between ALL the legs of all transistors at the solder points on the board all the carbon was gone and no more arcs. Tomorrow I'll get to see if it works. For tonight, I did get a power light ...and no arcs 🙂
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An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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An externally hosted image should be here but it was not working when we last tested it.
Sweet, that is great. Did you be sure to smear the paste around on the bottom of the transistors before installing in the sink and also to put a glob of paste on the thermistors that are between the output transistor drivers?
Everything is well. You can see the thermal paste by 113 and 114 at the screw holes in the middle in the next to last photo. My original complaint of the popping in the speaker was from Q33 arching. When I had it opened up and the bottom off of it I knew the transistors would not be setting flush and would warm up quickly so I'd find the hot one quick, which I did and came here stating Q33 was getting really hot really fast. Now we know it was all the arching of Q33 to begin with and for some reason Q1 wanted to arc as well. (weird) So put that down as another possible solution to popping in the channels of the PPI amps since they seem to like to Arc. This one was doing it in two places!
I had replaced the drivers from 32 to 37 with new ones so I guess that's just a freebie for the amp to have new outputs. I actually in retrospect didn't have to spend a dime. Worse, I was considering redoing the entire amp's transistors to get it all fresh and try to eliminate the problem (before I knew it was arching) and that would have just led to disappointment and a lot of money spent.
As of this moment the amp has been running for an hour at low volume just chugging along (1/3 volume) and sounding great and ice cold still. 🙂
Appreciate the help guys, thank you 🙂
I had replaced the drivers from 32 to 37 with new ones so I guess that's just a freebie for the amp to have new outputs. I actually in retrospect didn't have to spend a dime. Worse, I was considering redoing the entire amp's transistors to get it all fresh and try to eliminate the problem (before I knew it was arching) and that would have just led to disappointment and a lot of money spent.
As of this moment the amp has been running for an hour at low volume just chugging along (1/3 volume) and sounding great and ice cold still. 🙂
Appreciate the help guys, thank you 🙂
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Here's an update! After almost 2 hours of playing on the right channel ice cold I switched back to the left and the amp warmed up noticeably quick (a minute or less). Although it was playing fine for that moment, the Q33 is still getting very warm quickly. There's no popping in the channel and it is playing fine, but that one darn transistor seems to be bringing the amp temps up.
I don't know why and it is indeed playing clearly. I don't know for how long since I was hoping to get some feedback before leaving that channel going as it continues to get warmer by the minute as it stays hooked up.
If you can think of anything let me know 🙂
I don't know why and it is indeed playing clearly. I don't know for how long since I was hoping to get some feedback before leaving that channel going as it continues to get warmer by the minute as it stays hooked up.
If you can think of anything let me know 🙂
Actually that channel is back to making a bunch of noise again with that side overheating. UHG. Right back where I started. I think this is going to be a one channel PPI. Why would it go back to doing this after playing clearly for the first two minutes it was hooked up? Odd.
The noise in the speaker is it moving about as if you were holding a microphone and rubbing the mic to get various noises out of it.
Carbon was my initial problem, but now I don't know what. It was working fine for a few minutes.
Curiously now Q36 is giving me the most heat. I've scraped all the tracer holes for carbon.
The noise in the speaker is it moving about as if you were holding a microphone and rubbing the mic to get various noises out of it.
Carbon was my initial problem, but now I don't know what. It was working fine for a few minutes.
Curiously now Q36 is giving me the most heat. I've scraped all the tracer holes for carbon.
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That type noise is what happens when the transistors on the ceramic boards are acting up, try carefully adding a tiny bit of flux to their legs and resoldering them quickly.
Gotcha on that, but I did note that the noise is in relation to the heat of that channel. As it gets hotter the noise increases with the temp. We are talking a span of 5 to 8 seconds before it has to be disconnected. Those cards capable of that effect, heat?
The card could be causing the channel to get hot, the cards get pretty hot themselves normally. They are pretty stressed cards
Did you try cooling the card to determine if it's the card heating or something else heating that's causing the problem?
If you're really careful, you could move the card to the other channel to see if the problem follows the card.
If you're really careful, you could move the card to the other channel to see if the problem follows the card.
I re-soldered all the connections on the base of both cards as well the transistors on the card which is located on the side the drivers are getting hot. At this moment they are not popping and are staying cool just like they did last time where it worked for the first few minutes. It is definitely a connection issue somewhere and possibly the cards since it is behaving right now after removing the board and resoldering it. Right now however the amp is ice cold so let's see what happens once it warms up.
30 minutes later.......
An externally hosted image should be here but it was not working when we last tested it.
You shouldn't solder any components on the driver boards unless you can definitively find a fault (a broken connection). You may have been lucky this time but many times, soldering the connections can destroy the pads. I've seen pads on them draw up (leaving the bare ceramic board) even with indirect heating.
For such an awesome amp, these cards are horrible. They are weak, they lean over from heat, they seem to cause lots of headaches from some research I have done. PPI even extended the 600.2 by like an inch and a half and still didn't integrate them into the board.
Since this amp has given me such headache I'm not counting my cards just yet, but currently stable and ice cold. Soldering the cards and base pins seems to be the right thing to do this time around. 🙂
I'd have done that much earlier if we hadn't gotten off kilter with all that arc business. Guess this amp just had some demons that needed to be fixed. Hopefully that can stay past tense. Will continue to hammer it and update if anything else. 🙂
Since this amp has given me such headache I'm not counting my cards just yet, but currently stable and ice cold. Soldering the cards and base pins seems to be the right thing to do this time around. 🙂
I'd have done that much earlier if we hadn't gotten off kilter with all that arc business. Guess this amp just had some demons that needed to be fixed. Hopefully that can stay past tense. Will continue to hammer it and update if anything else. 🙂
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