I've several amplifiers of different sizes which are faulty. I haven't fixed them because I haven't a clue. This is the smallest culprit. 240v in (UK) and 12v dc to the board. Small neon lights when power button is on. Different dc voltages across all of the capacitors. Where do I go from here?
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How do you delete photo's once published. 2 I've just uploaded are better.Attached Files -
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Thanks for the diagram. Did you just work out the schematic by looking at my photos? You are really clever if you did. I'll work thro and let you know how I get on.Comment
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You think too well of me, these are just standard amplifier circuits on this chip.Comment
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I've checked all components and haven't found any faulty ones. I've pull the capacitors and their within 10% of stated values. Ic checks. Pin 1 is 7v Pin 2 is 16v pin 3 is 7v. Would you expect to see voltages on pin 1 and 3 which are the speaker outputs?
How do you manage to check the traces against the drawing? Turning the board over everytime to check the component impossible.Comment
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Hi,
The maximum supply voltage is 15 V in the datasheet. On pins 1 and 3 -7V this is normal. On pins 5 and 8 - 0.5 V is normal.
Try to trace the connections to the lumen with a lampLast edited by kasfamily; 05-05-2024, 11:59 AM.Comment
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Thanks for your advice. I've tried my bench magnifier but I'll try a fluorescent light for a brighter view. If all the tracks check out with a multimeter I guess I'll have to go for the last option of scrapping what could be a perfectly good tda 2822 chip and soldering in a replacement. I haven't got one so will have to order one.
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Good morning everyone,
I'm trying to repair an onkyo ht-r390 that has no sound output, despite the volume being at maximum, the rest seems to work; the video output signal (coming from an hdmi input) is present, but the audio is absent. Similar situation if I send an audio signal from any input I have no output.
The firmware reported is the following:
M:1.00/11107BLP
D:?.??/????????
O:1.00/11107AL
The DSP firmware given the question marks seems corrupt.
On the BCHDM-0678 - 25140678 - QPWBCHDM0678A0 board the chip that usually seems...05-11-2025, 02:59 AM -
Hi I have inherited the above desktop scanner, all seems to work correctly but there is no sound output. The only sound I do get from the speaker is the beep confirmation when you press a key. No output from the headphone socket either. Not even radio static with squelch fully turned down, tried a reset by holding 2, 9, and hold buttons but still no sound, does anyone have any experience with these scanners, thanks. -
Hi all, I've started this new thread in order to avoid further polution of thread "Yamaha RX-A3010 working, no sound output"
Just to recap:
No sound through Audio and AV analogue inputs, only sound when 2ch stereo or pure direct is activated (so no sound when I e.g. choose 7ch of Hall in Munich etc.). Hoever when I connect HDMI I've sound in all options (movie, music, eyc.) First suspicion was the DSP chip/PCB so I bought a scrap 1030 with a good functioning PCB (in this one a driver stage was defective (PRT DC: 67), after I swapped the PCB I've performed a factory... -
Hello
After months of trying I gave up my laptops sound card. I plan to solder a sound card on pcb inside my laptops case, probably connecting to usb ports inside. Do anyone has an experience to recommend pcb type audio/sound card suitable installing inside a laptop? Probably should have some type of amplifier for connecting to internal speakers ( speakers ).
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The off/on/auto switch was busted so i forced it into auto mode and now the blue light comes on but i don’t get any audio output. Does anyone one have any experience repairing this amplifier? I looked it over, checked some the of output transistors, some of the power resistors and cleaned that nasty conductive epoxy glue stuff off but not having much luck in the trouble shooting department.
I did however find a part of the PCB that was discolored from heat...03-22-2024, 06:00 PM
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