Amp has been on for about 2hrs. No speakers just occasional play on HEOS on Zone 3 Pre-out and Zone 1 on but not playing (same way it was since I started this thread)
Temperatures: (all in °C on silicon)
SR Temp 1 - 36
SR Bias - 38
SR Temp 2 - 39
FR Temp 1 - 52
FR Bias - 55
FR Temp 2 - 54
Center Temp 1 - 53
Center Bias - 51
Center Temp 2 - 49
FL Temp 1 - 51
FL Bias - 52
FL Temp 2 -43
SL Temp 1 - 49
SL Bias - 52
SL Temp 2 - 44
More measurements coming soon. These temps are a bit lower than what I was seeing last night.
Temperatures: (all in °C on silicon)
SR Temp 1 - 36
SR Bias - 38
SR Temp 2 - 39
FR Temp 1 - 52
FR Bias - 55
FR Temp 2 - 54
Center Temp 1 - 53
Center Bias - 51
Center Temp 2 - 49
FL Temp 1 - 51
FL Bias - 52
FL Temp 2 -43
SL Temp 1 - 49
SL Bias - 52
SL Temp 2 - 44
More measurements coming soon. These temps are a bit lower than what I was seeing last night.
I'm only talking about the circle that made it into my circle 😉. Concerned about the condition of the solder trail (via?) there
Coming off the board. It's still on the track, I was thinking some paste and hot air to stick it back down
I like the second one for this application, is that a piece of wire or just a carefully bent piece of solder?
Wire. Never ever bridge damaged print with solder alone. It is mechanically weak and will crack and fail.
What gauge is that wire? I have some Romex around the house but if it's smaller, guess I gotta take a trip to Home Depot
Obviously needs to be fixed. Luckily it looks pretty easy.
I literally have no idea how this happened. There was a tiny bit flux on the board, it must have leaked into the trace and started the decay, especially because of that heat. It looked burnt like with an iron but my iron was never that far into the board.
I literally have no idea how this happened. There was a tiny bit flux on the board, it must have leaked into the trace and started the decay, especially because of that heat. It looked burnt like with an iron but my iron was never that far into the board.
Traces can lift because of excess current under fault conditions.
If you identify the trace in relation to the circuit you might get a clue if high current was a factor. Fwiw it looks like one of the thicker traces which implies a high current area of the circuit.
If you identify the trace in relation to the circuit you might get a clue if high current was a factor. Fwiw it looks like one of the thicker traces which implies a high current area of the circuit.
So, that heat, along with the flux residue was enough.
Kept the old transistors around. The ohmmeter is getting OL on C+/E- (out of circuit) on the bias and very little resistance on the output transistors (B+/C- and E-) that I bought from another place than Denon. Lesson learned.
If I didn't test those properly, let me know and I'll test them properly with your instruction.
Kept the old transistors around. The ohmmeter is getting OL on C+/E- (out of circuit) on the bias and very little resistance on the output transistors (B+/C- and E-) that I bought from another place than Denon. Lesson learned.
If I didn't test those properly, let me know and I'll test them properly with your instruction.
OL collector to emitter is correct while 'very little resistance' from C to E implies a near short circuit. Most power transistors fail by going short C to E.
Grr. Now it's shorting.
I'm on my 3rd fuse from this issue and don't want to go through many more.
https://photos.app.goo.gl/2sijtA1vwLKWxgFbA
Inside the circled area, it all connects together with a continuity meter. Something tells me that's not right, especially because I am going through another fuse every time I plug it in
https://photos.app.goo.gl/rZsbXUKeHxFmgsKj9
I had to repair a little solder for the trace, but may have gone with too much.
I'm on my 3rd fuse from this issue and don't want to go through many more.
https://photos.app.goo.gl/2sijtA1vwLKWxgFbA
Inside the circled area, it all connects together with a continuity meter. Something tells me that's not right, especially because I am going through another fuse every time I plug it in
https://photos.app.goo.gl/rZsbXUKeHxFmgsKj9
I had to repair a little solder for the trace, but may have gone with too much.
You should probably try using a DBT (dim bulb tester) to prevent high current flow and fuse blowing although given this is a multi channel amp that may cause other issues. You might have to force zero bias current on all the working channels first in order to successfully use a DBT.
This is a complex amp and I just wonder if it is outside your comfort zone 🙂 if you are not used to working this kind of thing.
This is a complex amp and I just wonder if it is outside your comfort zone 🙂 if you are not used to working this kind of thing.
I just took out the wire I jumped the broken solder off and that fixed the fuse issue, now, I have to figure out why that wire is causing the short.
Wish I knew what to ask for finding a short.
I haven't worked on that channel so this is a new issue.
I really have no choice but to work on it myself. Won't do anything stupid and will have patience, but this board is no longer available and it's not worth shipping it to denon.
Wish I knew what to ask for finding a short.
I haven't worked on that channel so this is a new issue.
I really have no choice but to work on it myself. Won't do anything stupid and will have patience, but this board is no longer available and it's not worth shipping it to denon.
After checking every component on the schematic, followed the trails, and everything I could do without experience, I believe I am working on a multi-layer board. Nothing should be shorted and everything falls in line with the schematic
Identify any two points where you suspect a short and then identify those points on the actual circuit diagram.
Running the amp on a current limited supply would allow you to look at voltages and make sense of what is going on but don't be under any illusions of what is involved.
Running the amp on a current limited supply would allow you to look at voltages and make sense of what is going on but don't be under any illusions of what is involved.
All I can say for now, there is a definite issue (or so I believe).
J7508 and J7509 are shorted. From the looks of the diagram on both sides of the board, that shouldn't be happening
Looks like I have to desolder one end at a time of the jumper to follow it down to the short.
J7508 and J7509 are shorted. From the looks of the diagram on both sides of the board, that shouldn't be happening
Looks like I have to desolder one end at a time of the jumper to follow it down to the short.
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