New to this site, so Hi!
I received the mentioned amplifier and it got damaged somehow en route. When switching on one of the resistors on the L output board burns out. I changed the resistor and now it doesn't burn out but the one opposite on the R output does. I've done a physical inspection and replaced two other resistors that have burning on the board underneath them and also repaired some cold solder joints but don't really know what i'm looking for. Any help is appreciated. I can supply the schematics and photo's.
I received the mentioned amplifier and it got damaged somehow en route. When switching on one of the resistors on the L output board burns out. I changed the resistor and now it doesn't burn out but the one opposite on the R output does. I've done a physical inspection and replaced two other resistors that have burning on the board underneath them and also repaired some cold solder joints but don't really know what i'm looking for. Any help is appreciated. I can supply the schematics and photo's.
Thank you, I did think this but in the images the LED is green so it was functional before shipping. The LED stays red now so damage during transit is the only logical explanation.
I agreed a 50% refund because the item is worth saving.
I agreed a 50% refund because the item is worth saving.
Maybe so but that's not important right now. Are you able to advise on best to approach this? I am capable of removing and testing components, I don't need an experienced technician to do that.
First get and study the complete service manual, not just the schematic.
Then check in-circuit all of the parts in the output stage.
Remove any questionable parts and test them again out-of-circuit.
Examine the pcb for possible solder splashes, damage, etc.
Then check in-circuit all of the parts in the output stage.
Remove any questionable parts and test them again out-of-circuit.
Examine the pcb for possible solder splashes, damage, etc.
The most likely causes in such cases are the power supply, and the output stages.
Take the usual precautions.
Find the service manual, and if possible a reference circuit for the devices used, Sony tended to go near the voltage limits in some cases, and in any case, their designs tended to be, well, creative at times.
I assume you have a good set of meters, I tend to use digital and analog types.
A magnifying glass is very useful, I would start the job with a complete strip down and cleaning, the check the selector, spray the pots.
With the supply disconnected from load, check its voltages, unloaded transformers may read high at times.
Check the output for dead shorts and so on before power up, sometimes a shorted speaker wire is the cause of failure, people tried to connect a speaker with the power on, no protection in circuit, and fried the outputs....
Keep us informed.
And please post a photo of the output stage so that the devices are easily identified.
Take the usual precautions.
Find the service manual, and if possible a reference circuit for the devices used, Sony tended to go near the voltage limits in some cases, and in any case, their designs tended to be, well, creative at times.
I assume you have a good set of meters, I tend to use digital and analog types.
A magnifying glass is very useful, I would start the job with a complete strip down and cleaning, the check the selector, spray the pots.
With the supply disconnected from load, check its voltages, unloaded transformers may read high at times.
Check the output for dead shorts and so on before power up, sometimes a shorted speaker wire is the cause of failure, people tried to connect a speaker with the power on, no protection in circuit, and fried the outputs....
Keep us informed.
And please post a photo of the output stage so that the devices are easily identified.
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https://forum.allaboutcircuits.com/...-fa3es-amplifier-with-burnt-resistors.196894/
https://audio-database.com/SONY-ESPRIT/amp/ta-fa3es.html
It has Mosfet outputs.
And a really complex circuit.
Have fun.
https://audio-database.com/SONY-ESPRIT/amp/ta-fa3es.html
It has Mosfet outputs.
And a really complex circuit.
Have fun.