Herrenvolk
New Member
Hoping this is the right board for this.
This began about a month ago, I accidentally ordered a multimeter from Hong Kong and it took this long to arrive. I've no exact idea what may have caused my problems, so I'll post everything significant that's happened with this unit. When I bought it, the sx3800 had a problem where the left channel had more bass than the right channel. About a month ago I took it to a gathering of friends and it has two unfortunate things happen to it, a pizza box was left over it's vent for ten to fifteen minutes and it suffered a ~2ft tumble from a stationary car. After finding the pizza box on it, I turned it off and let it sit to cool off for twenty or so minutes, throughout the next few hours it got some light use and didn't exhibit any operational abnormalities.
The incident with the car happened on arrival home. I checked inside it immediately after it fell from the car, it hadn't and hasn't suffered any apparent damage from the shock, and it continued to function until early the next day.
I'd been listening to it for a short while when the right channel gives a pop and degrades in quality, and the unit strong burning smell(not the smell from over volted, burning electronics. I've smelt this before, from functional units under normal operating conditions, just not as strong as here. I don't know what components give it off, so I can't describe it further than that.). I quickly turned it off, and after leaving it for a minute, turn it on again. All the lights still come on, but the relay no longer clicks. I used some low wattage speakers to test the preamp and tuner, and both seem to function without problems. A few days ago I tried to take the voltages from the power amp to compare to some listings that I found on this forum, using the case as a ground. On testing pin 1, the voltage hovered around 23V before jumping into somewhere in the range of 40V, and the board emitted a burning electronics smell, which returns now whenever I power up the unit. Using the case as ground was guesswork, I hadn't seen a ground pin specified where the voltages were listed, but I wouldn't imagine that testing anywhere with a volt meter could cause a short, everywhere I've read about them states that a volt meter does not complete a circuit, which leads me to fear that my hands were shaky enough to cross pins 1 and 2.
The preamp still works,
Here is the manual I've been using, http://www.kallhovde.com/pioneer/sx-3800sm.pdf
I've seen people post about voltages, so if anyone has documents or knowledge to add to that, it would be appreciated, particularly voltage lists, part lists, and circuit diagrams.
Was I right in my method of measuring voltages, or terribly wrong, and if so, what is the correct way?
I still would like to check the power supply to be completely sure that the problem is the power amp/protection circuit.
I've misplaced the link from which I got my target voltages, so I can't post those.
This began about a month ago, I accidentally ordered a multimeter from Hong Kong and it took this long to arrive. I've no exact idea what may have caused my problems, so I'll post everything significant that's happened with this unit. When I bought it, the sx3800 had a problem where the left channel had more bass than the right channel. About a month ago I took it to a gathering of friends and it has two unfortunate things happen to it, a pizza box was left over it's vent for ten to fifteen minutes and it suffered a ~2ft tumble from a stationary car. After finding the pizza box on it, I turned it off and let it sit to cool off for twenty or so minutes, throughout the next few hours it got some light use and didn't exhibit any operational abnormalities.
The incident with the car happened on arrival home. I checked inside it immediately after it fell from the car, it hadn't and hasn't suffered any apparent damage from the shock, and it continued to function until early the next day.
I'd been listening to it for a short while when the right channel gives a pop and degrades in quality, and the unit strong burning smell(not the smell from over volted, burning electronics. I've smelt this before, from functional units under normal operating conditions, just not as strong as here. I don't know what components give it off, so I can't describe it further than that.). I quickly turned it off, and after leaving it for a minute, turn it on again. All the lights still come on, but the relay no longer clicks. I used some low wattage speakers to test the preamp and tuner, and both seem to function without problems. A few days ago I tried to take the voltages from the power amp to compare to some listings that I found on this forum, using the case as a ground. On testing pin 1, the voltage hovered around 23V before jumping into somewhere in the range of 40V, and the board emitted a burning electronics smell, which returns now whenever I power up the unit. Using the case as ground was guesswork, I hadn't seen a ground pin specified where the voltages were listed, but I wouldn't imagine that testing anywhere with a volt meter could cause a short, everywhere I've read about them states that a volt meter does not complete a circuit, which leads me to fear that my hands were shaky enough to cross pins 1 and 2.
The preamp still works,
Here is the manual I've been using, http://www.kallhovde.com/pioneer/sx-3800sm.pdf
I've seen people post about voltages, so if anyone has documents or knowledge to add to that, it would be appreciated, particularly voltage lists, part lists, and circuit diagrams.
Was I right in my method of measuring voltages, or terribly wrong, and if so, what is the correct way?
I still would like to check the power supply to be completely sure that the problem is the power amp/protection circuit.
I've misplaced the link from which I got my target voltages, so I can't post those.