I'm trouble shooting a bad channel in a portable pa system. I suspect a dual OP amp is bad in one section. I want to signal trace the output of the B amp with an old Radio Shack audio signal tracer but don't know if this is feasible and won't cause damage. Thanks
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Use an oscilloscope and a tone generator and bob is your uncle. -
What model signal tracer is it?
There is pretty much no risk using one to probe the op-amp's pins. You can also measure DCV on each pin to see if that is right, or inject a test tone say 1kHz and measure ACV if your multimeter can handle DC present.
Rarely, a signal tracer's input capacitor can charge up and zap the next test point. If you are on a node with say 40VDC the cap charges and next touching a 5V node it discharges. So I will touch ground in between test points.
It depends on the sig tracer input circuit. More of an issue on tube gear where you have 300V present.
NJM2068 is pretty much a vanilla part, although the SIP-8 package is discontinued and harder to find.Comment
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Thank you. I have one of the simple Radio Shack Signal tracers to trace rf, if and af. I looked at the schematic for the tracer and it does have a capacitor in the circuitry for isolation. Worked fine to trace audio to limiter stage before going into power amp units for left and right channels. Need to trouble shoot more as I still have no channel output past this point. Thanks for the help 😊
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Hi everyone, over the past few months i have taken a deep dive into motherboard diagnostics and I love the challenge. Currently im trying to learn all about the signals that travel around the motherboard, such as frequencies, enable signals High and Low logic states etc. And i have been learning to read and using the Schematics for this board that i requested here on Badcaps forum, from a few months ago, this is such a great place for these.
I’ve been working on a GA-970A-DS3 (rev. 1.0) that does not post. This motherboard has been my main learning board. I would like share...11-23-2023, 11:02 PM -
I have a Yamaha Stagepas 300 PA system with the left channel out. There are separate power inputs to each Power Amplifier. I repaired the left channel amplifier so both work. However, I still have no left channel output to speaker. Both speakers are good. I have a multimeter and an old Radio Shack signal tracer for troubleshooting and that's it. I checked all voltage inputs to both amps and they match. Don't know how to proceed to check or trace signals or voltages at amp outputs BEFORE they go to speakers. Any help appreciated. Thanks in advance, Dave -
Failure Symptom
No picture, just red vertical stripes. Google search shows quite common problem for these recent Vizio M series although red vertical stripe pattern may differ. Some call it "Netflix" boot screen haha.
Where is the short?
Panel has 4x buffer boards. Quickly found the 1/4 panel buffer board with the problem by selectively disconnecting buffer board flex cables.
Having recently fixed another Vizio with similar symptoms that was a shorted ESD diode array ( link ) Probed the ESD diode array but... -
Budm and redwire recently introduced me to using a signal tracer. I used a pair of amplified speakers and a special built probe, but well, my speakers need to go back to my computer, and I ordered one of these mono amps from ebay.
https://www.ebay.com/itm/1Set-LM386-...O/383526526009
It helped me find a problem in record time, so seems like it deserves a place on my bench, so I'm going to design a 3d printed box for it. But I haven't used one except for once. What features should it have?
I was originally going... -
Good morning.
I have posted here before and have gotten AMAZING advise (thank you!). I'm back for more. This BCaps Sub Forum is so well attended I thought I would post here.
This question is for an automotive application but has to do with what are essentially electrical questions and problem solving... If this is inappropriate I get it. Feel free to delete it or move the question.
The V 12 Jaguar XJS is notorious for overheating in stop and go traffic in hot weather... Y'all will be potentially helpinh a LOT of people. The solutions and directions...
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