hello great people of this awesome forum, have issues with one Digital Designs M3a blown the power supply mosfets ,has been replaced but now have an undesirable consumption more than one amp no inputs, the amplifier sounds, heat up within few minutes, removed the driver board and back to normal, no
abnormal consumption at all, just 120mAh and everything keeps cool, have digging in the forums but didn't find any info, the M3a driver board looks like the Hifonics BXi2610D driver board, have those defaced IC on the bottom, here the pic: https://drive.google.com/open?id=0B5iEUviWbCAZYVQwdmpyYVVoT00
if anyone have more info will be very useful , btw already check the transistors and resistors in the board and looks fine. thanks again !!
abnormal consumption at all, just 120mAh and everything keeps cool, have digging in the forums but didn't find any info, the M3a driver board looks like the Hifonics BXi2610D driver board, have those defaced IC on the bottom, here the pic: https://drive.google.com/open?id=0B5iEUviWbCAZYVQwdmpyYVVoT00
if anyone have more info will be very useful , btw already check the transistors and resistors in the board and looks fine. thanks again !!
I dont understand at all. You have repaired amplifier and amp is drawing more current than You think it should?
What is the idle current? Otherwise amp is functioning properly? If its drawing more than 1A (till about ~5), its perfectly normal for that size amplifier.
Heats up? Amp is clamped down to the heat sink?
What is the idle current? Otherwise amp is functioning properly? If its drawing more than 1A (till about ~5), its perfectly normal for that size amplifier.
Heats up? Amp is clamped down to the heat sink?
Sorry for the misunderstanding, yes the amplifier is drawing more current at idle, i have another one in good working order it only draws 120mAh, the output MOSFETs warm up very fast with the heatsink clamped, without the driver board there is not current draw.
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The transistors Q7, 11, 19 and 22 along the top of that driver board fail. They may check OK in the board but should be replaced.
mah is a quantity, like the capacity of a battery. ma is current flow.
You can't have 'no' current flow without the driver board unless the power supply shuts down because the power supply will draw some current.
This is a self-oscillating amp. Some self oscillating amps won't oscillate (amplifier stage) unless driven with a signal. Are you sure that your other amp was oscillating at the output stage when you only read 120ma of current draw?
mah is a quantity, like the capacity of a battery. ma is current flow.
You can't have 'no' current flow without the driver board unless the power supply shuts down because the power supply will draw some current.
This is a self-oscillating amp. Some self oscillating amps won't oscillate (amplifier stage) unless driven with a signal. Are you sure that your other amp was oscillating at the output stage when you only read 120ma of current draw?
thanks Perry, the auto complete on smartphone turn mA into mAh sorry about that, the good working amp it's drawing around 120mA at idle, the "bad" one it's at 1.2 -1.5 amp at idle fast warm up the output mosfets in less than 30 sec, all test has been done with the heatsink attached, this driver board us to fail very often, reading about Sundown 1500 seems like it's the same DWM1216FV board, the U2 =TL072 did you know what is the U3 ? would like to replace all transistors and ICs on it, just to make sure.
U3 is an LM211. Confirm by checking for 0 ohms between pins 1 and 4.
Also confirm that you have 12v between the NPN and PNP driver transistors collectors for each pair of SOT-89 transistors (generally marked AG/DK).
Also confirm that you have 12v between the NPN and PNP driver transistors collectors for each pair of SOT-89 transistors (generally marked AG/DK).
thanks to all , just bought the replacement part, they aren't expensive Hifonics DWM1216FV PWM Audio Driver PCB | eBay
the card just arrive, a little bit delayed, now the current draining stop but the amplifier have a high pitching sound coming out from speakers quite loud with no audio input, with very low audio signal goes into protect, the replacement board it's brand new. could be defective ?
CY is better. For the DK part, higher rail voltage often caused a malfunction.
I doubt that the board is defective.
Do you have access to a scope?
I doubt that the board is defective.
Do you have access to a scope?
Are you getting rail-rail oscillation of approximately 100kHz on the output transistors?
What is the frequency of the noise on the speaker terminals?
Without the scope...
Does the amp go into protect with signal but no speaker?
What is the frequency of the noise on the speaker terminals?
Without the scope...
Does the amp go into protect with signal but no speaker?
ok unfortunately i can't get my tools for now, this is what i have for now just take few pics of the inductors, they looks fine to me, both cards doing exactly the same pitch sound on speaker have to wait till my wife back from US to get my tools, she take my workshop keys with her dunno why >< sorry about that. thanks a lot again there is the recorded sound into the links .
https://drive.google.com/open?id=0B5iEUviWbCAZUE5SY2p0c2VZLTg
https://drive.google.com/open?id=0B5iEUviWbCAZY3owa2QybXZENk0
https://drive.google.com/open?id=0B5iEUviWbCAZUE5SY2p0c2VZLTg
https://drive.google.com/open?id=0B5iEUviWbCAZb2w4TTNjTHhJVkU
https://drive.google.com/open?id=0B5iEUviWbCAZUE5SY2p0c2VZLTg
https://drive.google.com/open?id=0B5iEUviWbCAZY3owa2QybXZENk0
https://drive.google.com/open?id=0B5iEUviWbCAZUE5SY2p0c2VZLTg
https://drive.google.com/open?id=0B5iEUviWbCAZb2w4TTNjTHhJVkU
Moving pots makes no difference, twist or hit the inductors neither.
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