Hi.
A friend of mine has a KRK Rokit 8 that stopped working.
Funny thing is that while he showed me the monitors in his home studio, for some reason it started working and after half a minute or so died again. Main power on the monitor was ON the whole time.
After opening it, on the PCB it says:
PN:23AM03000309 / MODEL RPG3V2 MAIN / DATE 2014 02 12 VER A2.
On the back of the monitor it says MADE IN CHINA...
After learning that it came back for a short time, I suspected a cold solder joint, but It is hard to find anything on this PCB. It has a clear silicone type paste on some caps and by the way is SMD technology.
Anyone knows where to get the schematic for this particular circuit?
ANy other ideas?
Phantombox
A friend of mine has a KRK Rokit 8 that stopped working.
Funny thing is that while he showed me the monitors in his home studio, for some reason it started working and after half a minute or so died again. Main power on the monitor was ON the whole time.
After opening it, on the PCB it says:
PN:23AM03000309 / MODEL RPG3V2 MAIN / DATE 2014 02 12 VER A2.
On the back of the monitor it says MADE IN CHINA...
After learning that it came back for a short time, I suspected a cold solder joint, but It is hard to find anything on this PCB. It has a clear silicone type paste on some caps and by the way is SMD technology.
Anyone knows where to get the schematic for this particular circuit?
ANy other ideas?
Phantombox
Shutting off can also be a thermal/overload problem.
Check fan (if fitted) is working and vents aren't blocked with dust
Look for disconnected wires.
A good visual check first costs nothing and doesn't require any equipment.
Check fan (if fitted) is working and vents aren't blocked with dust
Look for disconnected wires.
A good visual check first costs nothing and doesn't require any equipment.
It is a studio monitor which is airtight except for a bass reflex hole on the front.
It does not have a fan.
All wires were connected (verified) before I took out the amp.
I'm aware that shutting ON/OFF repeatedly may cause trouble. Both monitors usually get turned ON whenever someone is working in the studio and turned OFF when he or she is done, so there would not be any excessive use of the power switch.
The other monitor (they come as a pair) still sound ok. And the strange part is that for no particular reason (not manipulating the monitor in any way) it came back for a shor time.
It does not have a fan.
All wires were connected (verified) before I took out the amp.
I'm aware that shutting ON/OFF repeatedly may cause trouble. Both monitors usually get turned ON whenever someone is working in the studio and turned OFF when he or she is done, so there would not be any excessive use of the power switch.
The other monitor (they come as a pair) still sound ok. And the strange part is that for no particular reason (not manipulating the monitor in any way) it came back for a shor time.
The silicone type stuff on the PCB looks like wax used in some receivers. Any idea of how to remove this?
They don't want you to work on it. Solvents that might dissolve coatings have their own dangers.
Best buy another board. Check farnell.com evaluation kits if you don't have a more inexpensive source of amp boards.
Hint, check solid state for sources of kit boards you can build out of leaded components and with no coating.
Check chipamps forum for lower power kits, 25 (LM1875) to 75 watts (TDA7594).
Best buy another board. Check farnell.com evaluation kits if you don't have a more inexpensive source of amp boards.
Hint, check solid state for sources of kit boards you can build out of leaded components and with no coating.
Check chipamps forum for lower power kits, 25 (LM1875) to 75 watts (TDA7594).
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Ehi, that sounds like "conspiration" !
Truly, it's because of vibrations and how to easily remove some rattle, being the PCB with components mounted inside the box with the woofer.
I think I got it working again.
I swapped a 150uF 35V cap and re-soldered all pins on the power ICs (TDA75xx) and did the same on all the other electrolytic caps.
BTW, the waxy substance got right off with a plastic screwdriver. Although, so would the SMD components as well, so I left most of the wax on...
I swapped a 150uF 35V cap and re-soldered all pins on the power ICs (TDA75xx) and did the same on all the other electrolytic caps.
BTW, the waxy substance got right off with a plastic screwdriver. Although, so would the SMD components as well, so I left most of the wax on...
Wax comes off with heat ... I believe if you heat it with a gun from some distance it may work. I remember using cellophane paper for removing wax from clothes with an iron...
I thought these used a TDA7294?
tda7294-failure
the silicone stops (hopefully) the caps leads failing due to vibration
tda7294-failure
the silicone stops (hopefully) the caps leads failing due to vibration
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