I just received a about 10 of these amplifier all look new externally. This one reads a dead short across the power supply, pulled board and replaced the D1 but noticed that Q12 is blown as well.
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Q12 is an AO340. This is odd, I've not seen this transistor blow. This is a switch in the muting circuit that looks for 50Khz clock from the MCU.
When you replaced D1, was the short removed?
When you replaced D1, was the short removed?
Yes the short is removed. Bill what is the imprint or can this be found on the scap boards I have a cxa 300-600 or a d 1000. 1d?
I don't see a micro controller on either of the smaller cxa boards. But one is present on the dx1000.1. I'll place an order if not.
I don't see a micro controller on either of the smaller cxa boards. But one is present on the dx1000.1. I'll place an order if not.
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CXA300.1 or 600.1 don't use MCU's.
I believe the DX1000.1 uses a quad op (LM393?) amp not an MCU.
Not sure what your asking when you say imprint. Are you asking about the MCU? U1-STM32F030F3
I believe the DX1000.1 uses a quad op (LM393?) amp not an MCU.
Not sure what your asking when you say imprint. Are you asking about the MCU? U1-STM32F030F3
The marking on the transistor I need. But I have placed an order for the correct components. Once they arrive I will repost.
OK so the Q12 part came in replaced the mosfet. Now the short is removed from the power supply but it just won't start, it's just stuck like it about to start up, but never draws the current then starts.
If the amp does not power up, D2-1N4148 and Q22-BC807 may have failed. Replace both even if both check ok.
Change both out. Tested good in curcuit, but changed them anyway. Amplifier now draws current about the normal amount for start up around 9 amps and holds there instead of dropping, so I shut the supply off.
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No, if i install the mosfets and attempt to power up the amplifier, it just draws current about 8-9 amps like it would at start up, but just stays there.
Are you showing both gate drives from the PSU controller in phase? That would be a problem.
Because Q12-A03404 burned up I would look at IC17,ZD6-TL431,L4-(I don't have a value, but will look it up). Check the temperature in this circuit, something may be getting hot.
This is an unusual problem, I don't believe I've run across it.
This is an unusual problem, I don't believe I've run across it.
Russel, the PSU is a Boost Converter and only has one drive pulse from UC3843 to three IRFB4110's in parallel.
When the L4 was removed i did not see there was a secondary winding under the potting material. I repaired the connections. The amplifier draws more current now. It maybe damaged
Try swapping another L4 from one of the other boards you have to see if this will fix the problem. The 46CXA12001 boards also use the same L4.
FYI I measured 3.1uH on primary and 38.9 mH
FYI I measured 3.1uH on primary and 38.9 mH