kuisis Posted October 15, 2004 Share Posted October 15, 2004 I noticed lately when touching the faceplate of my 233 scott amplifier that I get a mild shock. It doesn't happen all of the time, but I don't think it should happen at all. Does anyone know if any of the ground wires are prone to getting loose, or any other cause. Thanks Quote Link to comment Share on other sites More sharing options...
WS65711 Posted October 15, 2004 Share Posted October 15, 2004 It sounds like static electricity to me. Did your weather turn cooler & drier lately? Check and see if touching one of the metal screws that hold the switchplate on the lightswitch of your room doesn't give you the exact same slight shock. Dave Quote Link to comment Share on other sites More sharing options...
kuisis Posted October 15, 2004 Author Share Posted October 15, 2004 No It's not that, We've had the wettest summer I can remember and it's been happening for a while. Quote Link to comment Share on other sites More sharing options...
LarryC Posted October 15, 2004 Share Posted October 15, 2004 Did you try reversing the plug? I think you'd be wise to check it out, especially if that doesn't do it. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 15, 2004 Share Posted October 15, 2004 Sounds like a ground cap is going south... These usually have something to do with suppressing hum. That's my guess... DM Quote Link to comment Share on other sites More sharing options...
WS65711 Posted October 15, 2004 Share Posted October 15, 2004 Going south??? Like in Hope, Arkansas? Or New Orleans? Is there something BAD about the south? Quote Link to comment Share on other sites More sharing options...
kuisis Posted October 15, 2004 Author Share Posted October 15, 2004 I had the amp rebuilt about one year ago so I would hope nothing is going south, or north, east, west either. I know nothing about electronics so how would I test for this, I have a multimeter. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 15, 2004 Share Posted October 15, 2004 Bear in mind that I am no expert on the matter. Are you hearing any hum? This should be apparent if what I am suggesting is true. Aside from having at least one bad ground cap, the whole grounding issue is in doubt... It is unusual to have a build-up of voltage on the chassis if it is properly grounded in the first place. Does the AC plug have a ground, 3-prong plug? And is the outlet correctly wired for ground? In the case of a 2-prong plug, as was suggested above, reversing the polarity may help. Otherwise, you should run a wire from the chassis to real earth ground, like to a water pipe or such. If it hums when you have a good earth ground on it, then it is definitely a capacitance problem. Cap chasing is not real easy. The hard part will be finding the culprit by eye, unless you have a schematic...I would be looking first for small disk-type caps wired to the output jacks. That's a guess. How one would find it by eye depends on the layout of the thing. I would look first at the caps that would be associated with the output jacks. If it is a strip, there will be at least one cap bridging the 2 elements of the positive and negative portions of the RCA jack. The outer "ring" is the ground. Where exactly this occurs could be a matter of tracing the thing down, so nobody can really say. Best of luck, but try a true earth ground first. DM Quote Link to comment Share on other sites More sharing options...
kuisis Posted October 15, 2004 Author Share Posted October 15, 2004 Dman Thanks for all the help. I'll try all of those things Tom Quote Link to comment Share on other sites More sharing options...
WMcD Posted October 15, 2004 Share Posted October 15, 2004 This is definitly a safety issue. You must have it fixed. You're playing with your life and that of your loved ones. Seriously, Gil Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted October 15, 2004 Share Posted October 15, 2004 kuisis Like Gil said this could be a real safety issue and you should get it checked for how much AC voltage to earth ground exist. If the power transformer(internally)or AC wiring has developed leakage(short) to the scott chassis it would be possible to get shocked when touching the chassis/faceplate. Any good electronic repair shops should be able to run an AC Leakage Current test for you. Its a test that should be ran on any equipment after being serviced. Also never use a cheater plug on a television if it has a two prong AC cord with one blade thats wider because alot of TV's have what called a Hot Chassis and by reversing the AC plug you can put 120v AC on external points like Antenna terminals and audio input/output jacks! mike Quote Link to comment Share on other sites More sharing options...
kuisis Posted October 19, 2004 Author Share Posted October 19, 2004 Thanks for the concern guys. I checked the ground and that solved the problem. Quote Link to comment Share on other sites More sharing options...
richinlr Posted October 22, 2004 Share Posted October 22, 2004 ---------------- On 10/15/2004 9:41:24 AM kuisis wrote: I noticed lately when touching the faceplate of my 233 scott amplifier that I get a mild shock. It doesn't happen all of the time, but I don't think it should happen at all. Does anyone know if any of the ground wires are prone to getting loose, or any other cause. Thanks ---------------- From the obscure annals of audiophiledom comes the recommendation to check the polarity of your mains cord and confirm that it is actually wired correctly. I can't remember exactly how to do it but Sumiko used to have a paper on the process of checking this. You might try to get in touch with Sumiko to see if anyone there can find the paper for you. When I checked my components several years ago, I found a significant number of them were wired BACKWORDS. Even a $1,000 Musical Fidelity DAC! When wired backwards there is a larger voltage between the chassis and ground. You changed the orientation of the power cable leads to produce the lowest potential. Results are less risk of shock, noticebly reduced hum and noise from your entire system. Highly recommended process. Quote Link to comment Share on other sites More sharing options...
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