Hey guys, I have a Sony STR-DE875 receiver that keeps blowing the fuse! I am a mostly- broke college student and would like to figure out how I can fix this thing without going broke. Has anyone had any similar experiences with these receivers? Is there somewhere I can go to get parts?
I have very little experience with home audio, but I am a telecom technician, so minor repairs I should be able to handle. From what I have been reading, Sony receivers are junk, but I would jsut as soon not buy a new one if I don't have to.
Thanks a lot for your help.
Ryan
I have very little experience with home audio, but I am a telecom technician, so minor repairs I should be able to handle. From what I have been reading, Sony receivers are junk, but I would jsut as soon not buy a new one if I don't have to.
Thanks a lot for your help.
Ryan
"It blows the fuse" really isnt enough. This could be anything from a shorted bridge rectifier, shorted primary/secondary winding on the transformer, shorted output terminals, relay, failed output/driver devices, excessive DC in the front end, anything really.
If you have no experience with electronics diagnosis you're pretty much wasting your time. Take it to someone who knows what they're doing.
If you have no experience with electronics diagnosis you're pretty much wasting your time. Take it to someone who knows what they're doing.
By far the most common cause of this, espeicially in Sony receivers, is a blown output transistor. You will need to find out which channel (or possibly channels) has the blown transistors and replace both (never just one). The receiver uses an IC as a driver stage, and it is likely to have built-in protection against overloads, so it is likely that this IC was not damaged. You should check the bias circuitry and the passive devices for the affected channel to make sure that they appear good. Wouldn't hurt to just replace the bias transistors just in case.
The output devices are almost certainly MN2488 and MP1620. Generic equivalents are 2SD2488 and 2SB1620.
Lots of info can be found on the web regarding this type of repair. Just searching on the part numbers above will yield a lot of hits.
The output devices are almost certainly MN2488 and MP1620. Generic equivalents are 2SD2488 and 2SB1620.
Lots of info can be found on the web regarding this type of repair. Just searching on the part numbers above will yield a lot of hits.
Hey Perry1977,
Compared to new stuff, Sony is not what I'd call junk. It's actually not bad for the average receiver. What you read about here is not what moves in stores so don't feel bad.
One thing to say, don't cause more damage. If you aren't comfortable, get some help or find an honest shop (it's cheaper than replacing the set). You very likely have blown outputs and drivers, due to speaker loading, wire short or party. The other good killer is no clearance above your receiver. Macboy has the correct part numbers so there you go.
Install new insulators, clean the heatsink and use new FRESH grease (don't use too much). Do not over tighten the transistors. Test the other resistors in the area as well as small transistors. Esp. the bias transistor.
-Chris
Compared to new stuff, Sony is not what I'd call junk. It's actually not bad for the average receiver. What you read about here is not what moves in stores so don't feel bad.
One thing to say, don't cause more damage. If you aren't comfortable, get some help or find an honest shop (it's cheaper than replacing the set). You very likely have blown outputs and drivers, due to speaker loading, wire short or party. The other good killer is no clearance above your receiver. Macboy has the correct part numbers so there you go.
Install new insulators, clean the heatsink and use new FRESH grease (don't use too much). Do not over tighten the transistors. Test the other resistors in the area as well as small transistors. Esp. the bias transistor.
-Chris
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