4003 Hum

grayk · Post by **grayk** » Tue Jan 02, 2007 2:49 pm

I am hoping someone here may be able to help me and pinpoint what my problem is with my Ric. It is a year 2000 4003 that has been quite well gigged over the last few years, but not abused. Problem started at a gig last week I noticed a crackling when I plugged into the standard jack which made me think time for a clean and a look inside. However before I got round to it I noticed the neck pickup volume had got a bit of a crackle also. I took the scratchplate off and the jack out to check everything and clean with a Q Tip cotton bud and some WD40 (Is this my problem???) on the pots and on the jack sockets. I put it all back together and it seemed great, crackles gone and no problems. The problem came at the 2nd gig after my clean-up. There was this horrible hum from my amp, quite loud and intrusive. It wasnt an earth type hum as touching the strings/metalwork did not get rid of it. At first I thought it was my amp but using the Ric through another amp proved it was the guitar where the problem was. Can anyone shed some light as to what it may be? I am thinking is it a pickup problem but it is there with both pickups solo'd. It points to me to be the toggle switch which is at fault. I would really appreciate feedback from you guys as to where I might look. I dont want to spend money if there is a simple fix. Many thanks in anticipation of your replies.

johnallg · Post by **johnallg** » Tue Jan 02, 2007 6:06 pm

Sounds like you have a grounding problem. Somewhere the ground has been compromised. If you have an ohmmeter ohm from the metal jackplate to all metal on the bass - tailpiece, bridge pup surround, neck pup housing, pup switch chrome, volume/tone pot bodies, etc. First, did you try other cords? Does it hum if you use the Ric-O-Sound jack (you'll only get the bridge pup but does it hum)?

grayk · Post by **grayk** » Wed Jan 03, 2007 12:50 am

John, thanks for your reply. Yes I tried everything in the chain, power cords and cables from the amp to the bass. I tried everything as I originally thought it was an amp problem. It was when I tried the second amp that it proved that the Ric was the problem. I am not familiar with using a meter to check out electrics so I would get a friend of mine to do so for me. It is something I should have got my head round at my age but I have never had a problem with the wiring on a bass in all my playing life ! I guess you could say I have been lucky. I did try both of the jacks to see if the hum was still there and it is. It was the 1st thing that I tried when I was on stage. The hum is there in both jacks. It does seem strange that this hum has only started since I had the pick guard off !!

johnallg · Post by **johnallg** » Wed Jan 03, 2007 6:19 pm

I would look for the ground coming from the jackplate to be broken loose where it is soldered to the pot bodies. You definitely have the ground wire loose, and seeing it is both jacks, I'd look at the jackplate to potentiometer ground wire integrity.

lars · Post by **lars** » Wed Jan 03, 2007 9:09 pm

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grayk · Post by **grayk** » Thu Jan 04, 2007 2:35 am

John/Lars. Thankyou very much for your hints and advice. I am sure it sounds like a similar problem to the one in the link Lars. I am going to look into it and will be sure to post our findings. Thanks again.

doctorwho · Post by **doctorwho** » Thu Jan 04, 2007 2:04 pm

You know why bees hum? They don't know the words!

grayk · Post by **grayk** » Tue Jan 09, 2007 5:09 am

An update on the hum problem. I am mystified, it persists ! I had my friend check it out over the weekend and everything checked out ok. The ground wires were all intact and eveything meter'd out fine. The pickups were showing 11K so no problems there I wouldnt think. I am at a loss, do I start replacing the pots ? This buzzing has only started since a dabbed a bit of WD40 on the back of the pots to lube them. Has the WD40 had an adverse reaction and bridged something within them ? I have been told that WD is bad for guitar pots, I wasnt aware at the time obviously. I will never use it again ! Could anyone help any further, it would be greatly appreciated.

redvette · Post by **redvette** » Tue Jan 09, 2007 5:31 am

Keith -- Get some contact cleaner from Radio Shack or any electronic parts house. Try cleaning the pots with it. If you can get the WD-40 out of the pots, the hum might subside. Otherwise, it is not too hard to replace the pots.

beatlefreak · Post by **beatlefreak** » Tue Jan 09, 2007 5:44 am

WD-40 should not be used as a lubricant on potentiometers. There are specific contact cleaners for electronics that contain lubricants.

johnallg · Post by **johnallg** » Tue Jan 09, 2007 8:47 pm

Agreed. And keep the WD-40 off the CV finish of the instrument!

beatlefreak · Post by **beatlefreak** » Wed Jan 10, 2007 6:32 am

In fact, it should be kept away from your guitars - period.

squirebass · Post by **squirebass** » Wed Jan 10, 2007 12:09 pm

Yeah, I was thinking you just need compressed air to blow out the potentiometers, not something like WD-40. But what does the WD-40 do to the Conversion Varnish? Does it contain Silicone?

soundmasterg · Post by **soundmasterg** » Wed Jan 10, 2007 12:28 pm

You should be using something like De-Oxit for cleaning pots on guitars. (or amps)

grayk · Post by **grayk** » Wed Jan 10, 2007 12:28 pm

Gentlemen thankyou all of you for your contributions on this matter. It would indeed now point to the fact that I have naively used WD-40 that has caused my pot(s) to ground out to some degree. Another friend of mine thinks that the WD has mixed with carbon deposits and caused some grounding with the body of the pot. It seems like sense to me. It has to be this as it only started when I (carefully with a Q tip) administered the WD. He has suggested that before I replace all the pots that I remove them and bathe the pots in methylated spirit to remove the WD-40 and any carbon deposits. As he said "I have nothing to lose in trying this" The great thing about meths is that it evaporates completely. If the worst happens and they are wrecked by this action then I will buy new pots. It has to be this as everything else checks out !