There is nothing obvious showing in the pictures so it will come down to doing some tests, initially static testing (without the power connected) but after that it will need to be with the power connected.
'''''If neither you or your son has any experience testing when exposed lethal voltages are present then don’t do it. It is not worth it'''''
[image|1991681]
(click on image to enlarge for better viewing).
I’ve highlighted some points of interest in the image above where you may wish to check first.
''With the power disconnected'' ('''green arrows''') use an Ohmmeter:
check that the fuse on the ‘power’ board is OK i.e. short circuit measurement shown on Ohmmeter
-
can’t see it to well but if the regulator shown on the ‘amp’ board is a [https://www.digikey.com/en/product-highlight/t/texas-instruments/tps54334-synchronous-buck-converter|TPS54334] then these are prone to failure over time.
+
can’t see it to well but if the regulator shown on the ‘amp’ board is a [link|https://www.digikey.com/en/product-highlight/t/texas-instruments/tps54334-synchronous-buck-converter|TPS54334] then these are prone to failure over time.
Not quite sure what you would measure when testing the regulator with an Ohmmeter in this particular circuit but you shouldn’t see a short circuit or an open circuit when testing across the pins. There are actually two regulators in the same package
-
If it is faulty and you cannot find a direct replacement a [https://www.monolithicpower.com/en/mp2307.html|MP2307] is an equivalent component.
+
If it is faulty and you cannot find a direct replacement a [link|https://www.monolithicpower.com/en/mp2307.html|MP2307] is an equivalent component.
You will need smd (surface mounted device) soldering tools and skills to remove / replace the component
If it is determined from the static tests that the two check points suggested are both OK (green arrows) then you will have to connect the power and perform “live” testing. '''''See note above re testing live circuits.'''''
-
Again can’t see it too well and I haven’t got a schematic to work from but the '''red arrow''' points to what I think is the STBY (standby) power lead going from the power board to the amp board. This should be a DC voltage, its’ value is unknown to me, but given the regulator operates at anywhere between 4.75V DC to 28V DC you shouldn’t see any DC voltage higher than the 28V DC and most probably it will be nearer the 5V DC mark.
+
Again can’t see it too well and I haven’t got a schematic to work from but the '''red arrow''' points to what I think is the STBY (standby) power lead going from the power board to the amp board. This should be a DC voltage, its’ value is unknown to me, but given the regulator operates at anywhere between 4.75V DC to 28V DC you shouldn’t see any DC voltage higher than the 28V DC
-
Check if there is a DC (~5V?) voltage on the lead.
+
Check if there is a DC voltage on the lead.
If there isn’t then there is a problem in the power board.
If there is then there is a problem on the amp board as the STBY power is to let the amp board “know” that power is available and it switches on the power light.
'''''Be aware that there is exposed lethal voltages on the power board when you’re doing this.'''''
There is nothing obvious showing in the pictures so it will come down to doing some tests, initially static testing (without the power connected) but after that it will need to be with the power connected.
'''''If neither you or your son has any experience testing when exposed lethal voltages are present then don’t do it. It is not worth it'''''
[image|1991681]
(click on image to enlarge for better viewing).
I’ve highlighted some points of interest in the image above where you may wish to check first.
''With the power disconnected'' ('''green arrows''') use an Ohmmeter:
check that the fuse on the ‘power’ board is OK i.e. short circuit measurement shown on Ohmmeter
can’t see it to well but if the regulator shown on the ‘amp’ board is a [https://www.digikey.com/en/product-highlight/t/texas-instruments/tps54334-synchronous-buck-converter|TPS54334] then these are prone to failure over time.
-
Not quite sure what you would measure when testing the regulator with an Ohmmeter but you shouldn’t see a short circuit or an open circuit when testing across the pins. There are actually two regulators in the same package
+
Not quite sure what you would measure when testing the regulator with an Ohmmeter in this particular circuit but you shouldn’t see a short circuit or an open circuit when testing across the pins. There are actually two regulators in the same package
If it is faulty and you cannot find a direct replacement a [https://www.monolithicpower.com/en/mp2307.html|MP2307] is an equivalent component.
You will need smd (surface mounted device) soldering tools and skills to remove / replace the component
If it is determined from the static tests that the two check points suggested are both OK (green arrows) then you will have to connect the power and perform “live” testing. '''''See note above re testing live circuits.'''''
Again can’t see it too well and I haven’t got a schematic to work from but the '''red arrow''' points to what I think is the STBY (standby) power lead going from the power board to the amp board. This should be a DC voltage, its’ value is unknown to me, but given the regulator operates at anywhere between 4.75V DC to 28V DC you shouldn’t see any DC voltage higher than the 28V DC and most probably it will be nearer the 5V DC mark.
Check if there is a DC (~5V?) voltage on the lead.
If there isn’t then there is a problem in the power board.
If there is then there is a problem on the amp board as the STBY power is to let the amp board “know” that power is available and it switches on the power light.
'''''Be aware that there is exposed lethal voltages on the power board when you’re doing this.'''''
Hi @tiffanylaw ,
There is nothing obvious showing in the pictures so it will come down to doing some tests, initially static testing (without the power connected) but after that it will need to be with the power connected.
'''''If neither you or your son has any experience testing when exposed lethal voltages are present then don’t do it. It is not worth it'''''
[image|1991681]
(click on image to enlarge for better viewing).
I’ve highlighted some points of interest in the image above where you may wish to check first.
''With the power disconnected'' ('''green arrows''') use an Ohmmeter:
check that the fuse on the ‘power’ board is OK i.e. short circuit measurement shown on Ohmmeter
can’t see it to well but if the regulator shown on the ‘amp’ board is a [https://www.digikey.com/en/product-highlight/t/texas-instruments/tps54334-synchronous-buck-converter|TPS54334] then these are prone to failure over time.
Not quite sure what you would measure when testing the regulator with an Ohmmeter but you shouldn’t see a short circuit or an open circuit when testing across the pins. There are actually two regulators in the same package
If it is faulty and you cannot find a direct replacement a [https://www.monolithicpower.com/en/mp2307.html|MP2307] is an equivalent component.
You will need smd (surface mounted device) soldering tools and skills to remove / replace the component
If it is determined from the static tests that the two check points suggested are both OK (green arrows) then you will have to connect the power and perform “live” testing. '''''See note above re testing live circuits.'''''
Again can’t see it too well and I haven’t got a schematic to work from but the '''red arrow''' points to what I think is the STBY (standby) power lead going from the power board to the amp board. This should be a DC voltage, its’ value is unknown to me, but given the regulator operates at anywhere between 4.75V DC to 28V DC you shouldn’t see any DC voltage higher than the 28V DC and most probably it will be nearer the 5V DC mark.
Check if there is a DC (~5V?) voltage on the lead.
If there isn’t then there is a problem in the power board.
If there is then there is a problem on the amp board as the STBY power is to let the amp board “know” that power is available and it switches on the power light.
'''''Be aware that there is exposed lethal voltages on the power board when you’re doing this.'''''
Hopefully this is a start