That's in the switching controler section, nothing to do with the class d controler! I think you buy a crap amp that was unfortunately not working! Look at IR2153 datasheet or L6571 from ST. It look like they use this as switching controler, so you will easily find purpose of your broken parts. I guess that the black SMD device is a gate diode or a PNP discharge transistor. I guess to that your electrolyt cap are for bootstrapping high side mosfet. Before to replace anything, just make sure that the switching power mosfet are not dead! To test your amp, find the start-up power supply, usualy a 3-5W resitor that go to the chip controler (the one closer to the power fet) and apply an external 12V to verify gate signal. Then, with the 12V still apply to the controler, add another 12V LO POWER source to the power mosfet and check signal at transformer. You should get a nice and clean 12V squared wave. After this, you should be nearly confident to put back AC power as usual...But already said, nice solder on board! Good luck with your purchase! (sarcastic!) 
Umm...
Power supply? I have plugged in 240V alternate on this thing, what you see in the pic is all I have, no external torroidal or power supply. I was told a switching power supply is on the board. It should have a SMPS Module on board whatever this means???
There is a PDF manual on the site, there are some imprecision in it, but with only few wires to connect I could work it out my self I hope. it does say Power supply 115 / 240v AC and then there are pins +1 -1 and ground
I did not use isolators between transistors and screws.
Some isolators were included and I used them in between the heat sink and transistor.
I also noticed the bad soldering yes, but ok I thought give it a push of luck.
I could try to post more pics if there is some details you need to see, but for now it seems I don’t have many hopes...
I just dont like the idea of having been ripped off.
Power supply? I have plugged in 240V alternate on this thing, what you see in the pic is all I have, no external torroidal or power supply. I was told a switching power supply is on the board. It should have a SMPS Module on board whatever this means???
There is a PDF manual on the site, there are some imprecision in it, but with only few wires to connect I could work it out my self I hope. it does say Power supply 115 / 240v AC and then there are pins +1 -1 and ground
I did not use isolators between transistors and screws.
Some isolators were included and I used them in between the heat sink and transistor.
I also noticed the bad soldering yes, but ok I thought give it a push of luck.
I could try to post more pics if there is some details you need to see, but for now it seems I don’t have many hopes...
I just dont like the idea of having been ripped off.
I have to say that I held back on comments about the build quality as most people don't like to hear that they have "done their money" but the controller board looks like the SMD's have been stuck on with no more nails.
The circuit diagram I found on the web site is not a schematic and it is impossible to follow the power supply path.
The circuit diagram I found on the web site is not a schematic and it is impossible to follow the power supply path.
I understood not wanting to discourage but at the same time not doing so was just giving false hope. Had he not suffered the failure he did and installed the controller board it was going to fail anyway.
It's not reflowed, the raw aerated carbonite globs are bridging many pins and components, IC's are right out of alignment. Should have never left the factory like that, and it is little wonder the guy doesn't answer his phone.
I know he's only going to feel so much worse the more time and effort he wastes on it. Do your research first next time and just view it as a cheap lesson.
I'd report this to whatever agency is available to you, I'm sure someone can recommend one. You probably won't get your money back. I hope you have a better experience next time.
It's not reflowed, the raw aerated carbonite globs are bridging many pins and components, IC's are right out of alignment. Should have never left the factory like that, and it is little wonder the guy doesn't answer his phone.
I know he's only going to feel so much worse the more time and effort he wastes on it. Do your research first next time and just view it as a cheap lesson.
I'd report this to whatever agency is available to you, I'm sure someone can recommend one. You probably won't get your money back. I hope you have a better experience next time.
Nothing too late...A repair is always a learning lesson! Yes you have switching power supply onboard...I just give you trick to test it before to put it back on direct 240VAC! If switching dont work properly, your amp will never work properly! Look at the parts I suggest you...you will have basic idea of the switching PSU used their!
Good luck
Good luck
This sure looks tacky guys!!
Did you do a Paypal transfer? They do have some customer protection procedures you see. I am lucky to never have needed it, but for as far as I know they can arrange a refund.
The unit sure is useless as is and unless you know a good way of repairing it I would send it back anyway. The soldering on that class D module is also VERY BAD!! They seem to have used reflow soldering paste but it looks like it didn't flow at all...
The fact that they scraped the codes of all the IC's makes it very hard to get 'round the functioning of the module too!
The whole unit looks like it has been put together ("designed") by apes (judging from the distance between certain components that really should be as close to eachother as possible). I cannot stress more to anyone NOT to buy from these guys!!!!
Did you do a Paypal transfer? They do have some customer protection procedures you see. I am lucky to never have needed it, but for as far as I know they can arrange a refund.
The unit sure is useless as is and unless you know a good way of repairing it I would send it back anyway. The soldering on that class D module is also VERY BAD!! They seem to have used reflow soldering paste but it looks like it didn't flow at all...
The fact that they scraped the codes of all the IC's makes it very hard to get 'round the functioning of the module too!
The whole unit looks like it has been put together ("designed") by apes (judging from the distance between certain components that really should be as close to eachother as possible). I cannot stress more to anyone NOT to buy from these guys!!!!
Frankly I find the differences between your board and the one in the datasheet quite striking!
There seem to be "fets" missing there near the output fets (or probably they are clamping diodes in similar package)
But there are faaaaaar more details different...
If you ever get your hands on the schematic you better pay attention to the rev.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
There seem to be "fets" missing there near the output fets (or probably they are clamping diodes in similar package)
But there are faaaaaar more details different...
If you ever get your hands on the schematic you better pay attention to the rev.
The area where the cap blew is part of the mains (primary) section of the board. The yellow transformer is supposed to provide safety isolation from the mains.
From what I can tell judging the pictures, it seems there is a PFC circuit located where your cap blew, and it is very unlikely that it has anyhing to do with the add-on board you forgot to plug in.
My guess is the cap blew because it was installed the wrong way or it was the wrong voltage or it blew because another failure propagated to it. In all cases it is a construction error and you are eligable to receive warranty support.
I'll have a closer look tonight, because the part numbers have been filed away (I don't like that... is the designer afraid someone will copy his application note derived implementation?). Anyway, even without part numbers this can be backengineered if you are desperate and want to try to fix the board yourself.
From what I can tell judging the pictures, it seems there is a PFC circuit located where your cap blew, and it is very unlikely that it has anyhing to do with the add-on board you forgot to plug in.
My guess is the cap blew because it was installed the wrong way or it was the wrong voltage or it blew because another failure propagated to it. In all cases it is a construction error and you are eligable to receive warranty support.
I'll have a closer look tonight, because the part numbers have been filed away (I don't like that... is the designer afraid someone will copy his application note derived implementation?). Anyway, even without part numbers this can be backengineered if you are desperate and want to try to fix the board yourself.
PFC?
No that's the SMPS controller circuit.
To me it looks like the capacitor was installed to the wrong side of the startup resistor, but I could be wrong as it's not 100% obvious how traces go below resistor or where the right side of it connects.
The little transistor that was blown off is a turnoff helper, PNP, and should be installed at the same angle as the other one.
Otherwise it could be because the output transistors were mounted without insulators between tabs and screws, shorting positive output of supply to ground. But I wouldn't expect a capacitor in the primary side SMPS circuit to explode from that...
No that's the SMPS controller circuit.
To me it looks like the capacitor was installed to the wrong side of the startup resistor, but I could be wrong as it's not 100% obvious how traces go below resistor or where the right side of it connects.
The little transistor that was blown off is a turnoff helper, PNP, and should be installed at the same angle as the other one.
Otherwise it could be because the output transistors were mounted without insulators between tabs and screws, shorting positive output of supply to ground. But I wouldn't expect a capacitor in the primary side SMPS circuit to explode from that...
I doubt this SMPS unit is so advanced to have PFC circuitry...
Anyway if you want the SOT23 device identified read this:
http://www.tkb-4u.com/code/smdcode/
Or google with the device markings and add "sot-23 device markings" and you'll probably find the part quite soon.
The location of the cap is kinda hard to figure out though...
I still really think it is only for the VERY well experienced engineer to reverse engineer this power supply without documentation.
Anyway if you want the SOT23 device identified read this:
http://www.tkb-4u.com/code/smdcode/
Or google with the device markings and add "sot-23 device markings" and you'll probably find the part quite soon.
The location of the cap is kinda hard to figure out though...
I still really think it is only for the VERY well experienced engineer to reverse engineer this power supply without documentation.
... What are you going to do? trash the boards or do you want to try and bring it back from the dead?
Woah :S
I recommend you reflow that board. There are shorts everywhere. you don't need a expensive hot air station, I use a butane heat pen that cost me £20
http://www.pro-iroda.com/Pro70K.htm
Works perfect.
On that note many SMT parts seem like they haven't stuck on right.
should do something like this:
http://www.youtube.com/watch?v=5x6ACO7iR0A
I think its a transistor, the PCB says Q13 where it was so it must be.
I'm suspicious of that capacitor even having been there, I'd say leave it out.
Not too sure about Q9, maybe it has fallen in place wrong when it was assembled. These things tend to spin round if you heat them when they are badly off centre.
I think just clean up the solder paste, get a new transistor, and flip Q9 around, and your good to go.
However *is not responsible is everything goes boom
* 
I recommend you reflow that board. There are shorts everywhere. you don't need a expensive hot air station, I use a butane heat pen that cost me £20
http://www.pro-iroda.com/Pro70K.htm
Works perfect.
On that note many SMT parts seem like they haven't stuck on right.
should do something like this:
http://www.youtube.com/watch?v=5x6ACO7iR0A
I think its a transistor, the PCB says Q13 where it was so it must be.
I'm suspicious of that capacitor even having been there, I'd say leave it out.
Not too sure about Q9, maybe it has fallen in place wrong when it was assembled. These things tend to spin round if you heat them when they are badly off centre.
I think just clean up the solder paste, get a new transistor, and flip Q9 around, and your good to go.
However *is not responsible is everything goes boom
*
Ridin '24'z said:Woah :S
I recommend you reflow that board. There are shorts everywhere. you don't need a expensive hot air station, I use a butane heat pen that cost me £20
http://www.pro-iroda.com/Pro70K.htm
Works perfect.
On that note many SMT parts seem like they haven't stuck on right.
should do something like this:
http://www.youtube.com/watch?v=5x6ACO7iR0A
I think its a transistor, the PCB says Q13 where it was so it must be.
I'm suspicious of that capacitor even having been there, I'd say leave it out.
Not too sure about Q9, maybe it has fallen in place wrong when it was assembled. These things tend to spin round if you heat them when they are badly off centre.
I think just clean up the solder paste, get a new transistor, and flip Q9 around, and your good to go.
However *is not responsible is everything goes boom
The smaller components self center more easily but the bigger IC's that are so far out of alignment are probably going to take some kicking.
Fixing that properly is more envolved than just applying a heat pen at this point. Personally I'd clean it all off and start fresh, but in the least it will require some new flux or there will be no self centering action, wetting, or clearing of bridges, and all joints would remain heavily oxidized.
The thing about a heat pen like you've shown is they're OK for a quick repair if you're stuck, and only for very small jobs like the video shows.
Their heat is uncontrollable, and too localized for a job that size, he'd end up burning the PCB with it. Better off using a heat gun and hitting all of the board at once with a more controlled and even heat.
I still disagree with trying to repair this at all. The meaning of repair implies that it once worked to begin with, or is at least capable of working by way of a simple fix or two, not an entire redesign or rebuild. There has never been an instance of these modules reportedly working.
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