I've got an eclipse amp here with a couple issues.The previous owner told me that the amp worked fine and then one day just quit working.I find it kind of hard to believe as both power supply fets (stp50n06) and both rectifiers are shorted.Is there anything that could suddenly go bad in a normally functioning amp that would cause this kind of damage?Also there is a couple diodes (zeners i believe) on the underside of the circuit board(smd device) that appear to be damaged.There is absolutely no markings as far as a part number on these things.Just the normal stripe marking the cathode.How would i go about determining a value to replace the bad diodes?
The fets is normal since they run parallel once one blows it overloads the rest and trashes all of them, maybe. I don't know as much about the diodes/rectifiers as far as the various causes that blow them, they don't blow near as much as the fets. Of course if a diode shorts it can make a mess.
Did you pull the rectifiers to check them? Shorted ral caps can make the rectifiers look bad and can also cause the rectifiers to fail.
The diodes are probably MELF components and won't have any markings. You will probably have to determine how they are being used (zener, rectifier...) to find a suitable replacement. If they are being used simply as a rectifier or to prevent current from flowing back into a circuit, virtually any replacement switching/rectifier diode will work. If it's being used as a zener in the regulator for the op-amps, it's probably a 16v zener.
The diodes are probably MELF components and won't have any markings. You will probably have to determine how they are being used (zener, rectifier...) to find a suitable replacement. If they are being used simply as a rectifier or to prevent current from flowing back into a circuit, virtually any replacement switching/rectifier diode will work. If it's being used as a zener in the regulator for the op-amps, it's probably a 16v zener.
the fets and rectifiers were trashed and i'm reading no shorts on the rail caps. I replaced the power supply fets and the rectifiers and the amp is now able to power up and make rail voltage(approximately + 21 volts) .The amp does not have any output though.I've yet to address the problem with the diode.I'm still in the process of figuring out exactly what its for.One end of it is tied to the outer legs of the rectifiers but i'm not sure where exactly it goes from there.
That's not too low. Anything over ±10 would be enough. I said ±15 because that's what most amps use.
If you have both plus and minus rail and regulated voltage, the power supply seems to be working.
At this point, you'd have to begin tracing the signal and/or checking op-amps.
I couldn't find any information on this amp. If you could post a couple of photos (of both sides of the board), they may be helpful.
If you have both plus and minus rail and regulated voltage, the power supply seems to be working.
At this point, you'd have to begin tracing the signal and/or checking op-amps.
I couldn't find any information on this amp. If you could post a couple of photos (of both sides of the board), they may be helpful.
If it's your amplifier, the leaded diode will work.
If the amplifier belongs to a paying customer, discuss it with them.
I'd suggest applying a dot of adhesive to the body of the diode to tack it to the board. This will take the stress off of the leads/pads when the amp is subjected to vibration.
The original part number may be RLS4148 if you want to order and exact replacement. The link is the datasheet for the RLS component. Compare it's measurements to the original diode before ordering.
http://www.rohm.com.cn/products/databook/di/pdf/rls4148.pdf
If the amplifier belongs to a paying customer, discuss it with them.
I'd suggest applying a dot of adhesive to the body of the diode to tack it to the board. This will take the stress off of the leads/pads when the amp is subjected to vibration.
The original part number may be RLS4148 if you want to order and exact replacement. The link is the datasheet for the RLS component. Compare it's measurements to the original diode before ordering.
http://www.rohm.com.cn/products/databook/di/pdf/rls4148.pdf
Most every amp I post about is something I purchased very cheaply just for the sole purpose of learning how to do this kind of work.I may use this amp in my car for a while to see how it holds up but I will definitely take your advice and put the proper parts into it before getting rid of it.Thanks again for the help and advice.
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