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Post by guitfiddler on Jun 2, 2015 18:13:58 GMT -6
I have a Sony R7 and it has static and noise in the output, and a looping pop even now and then. If I tap on top of the unit it sometimes goes away, but not any more. Does anyone know what could cause this?
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Post by svart on Jun 2, 2015 21:43:15 GMT -6
I have a Sony R7 and it has static and noise in the output, and a looping pop even now and then. If I tap on top of the unit it sometimes goes away, but not any more. Does anyone know what could cause this?
I have an Ibanez sdr-1k, which is a Sony made reverb unit of the same era/ pedigree. Mine did something similar and required having a lot of solder joints resoldered before all the noise and things went away. I'd expect you need to do the same. |
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crash
Full Member
Posts: 35 
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Post by crash on Jun 3, 2015 6:19:54 GMT -6
The Ibanez SDR1000 and the Sony Mur-201 were really similar animals with the R7 coming out after the Mur. I fixed one of the Ibanez units once just by taking it all apart and putting it back together. Don't know what fixed it other than maybe disconnecting and reconnecting all the internal cables. With used prices of the R7 these days, I would pop the top and give it a look and if that didn't do it with svart's suggestion, I would look for another used unit out there. I think I saw one recently over on GS for $250. I have one in my rack and it gets used all the time.
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Post by guitfiddler on Jun 3, 2015 8:36:44 GMT -6
I bought this unit used a few years ago. I took the casing off and it is surprisingly very clean inside except for the power transformer, which is rusty and one sony chip on the bottom side of the pcb looks like it has some residue on it. I will try and post some pics of it. I also read that because the pcb is so large that the weight of all the components over time can weight down the board and bend causing loose solder joints. Some people claimed they fixed the problem by just propping up the board with rubber spacers. I have a backup unit that works, but I would really like to get this unit working. I might make some IR's of this unit while I still have my backup unit working. Thanks
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Post by svart on Jun 3, 2015 8:41:45 GMT -6
The phenolic PCB that sony used back then wasn't nearly as stable as the fiberglass stuff we use today. I'm guessing the R7 has all the cables and connectors going everywhere like my SDR did. Over time, the phenolic relaxes and droops, and when it does, it'll break the solder joints and traces. Propping it up would likely mechanically fix an open circuit by making it touch, but isn't a long term solution.
on my SDR I reseated the cables and it worked for a while, but ultimately I found that wiggling cables just a tiny little bit would make the unit go in and out, so I resoldered everything. That worked for a while, until the next thing broke. I eventually cut the connectors off and soldered the cables directly to the PCBs and for the most part I've had no problems in years.
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Post by guitfiddler on Jun 3, 2015 19:03:42 GMT -6
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Post by guitfiddler on Jun 3, 2015 19:06:06 GMT -6
Thanks guys. If I can find time I will try and figure this one out. I realized that my pic is a little blurry...ugh
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