Rhodes MK II 73, no sound

[Leaozinho]

Hi there - first of all I'd just like to thank everyone on here for making this community so great.  This is my first post but I've been reading through stuff here and am continually amazed by the collective knowledge of this forum.

I recently acquired a Fender Rhodes Mark II, 73 keys, that's in great shape besides the fact that I'm not getting any sound.  I tried plugging the harp in directly, still no sound. 

I know there have been a lot of posts about this, and I think I have read many of them.  But I'm a total novice when it comes to wiring/electricity, so I had to start my own thread.  Anyway, I think the problem might be pickups, since using the screwdriver method I'm getting nothing from the upper half of the keyboard.  But just to make sure, how can I check that there are no shorts in the RCA cables?  What cables/connections do I need to check, and how?  (Keep in mind: total novice ).

If the wiring checks out, I guess I'll move on to the "alligator clip" method I've seen here.  It would be great to get some input though.  Thanks again, looking forward to getting started on this project!

-Hank

[Ben Bove]

Hey Hank, just wanted to clarify - you're getting no sound at all from the piano, or are you getting screwdriver-tapping noise from the lower half of the piano and nothing in the upper half of the piano?

So you've plugged a cable directly from the harp into an amplifier?  If you're still getting no sound going right to an amp and bypassing the piano's controls, then the rail is not the initial problem.

If you're not getting sound after a certain point on the piano, focus your attention on the pickups around those notes that first go silent.  Hand-check the wires that connect the pickups, moving them around lightly to see any breakage and look for any shoddy soldering.  Also make sure no tonebars are coming into contact with the pickups themselves - sometimes when they're badly out of adjustment, a tonebar can connect with the pickup's metal tabs and short the signal out.

Lastly, check the RCA jack at the top left to see if it's loose, flimsy wiring or any heavy corrosion etc.

Let us know what you find

[David Aubke]

Those pickups wrapped in white tape?

[Leaozinho]

@bjammerz:

Sorry, should have been more clear.  When I plug into the harp directly, playing the keys does not produce any sound, but the lower half of the pickups do produce sound when tapped with a screwdriver.  The upper half doesn't make any sound when touched with a screwdriver. 

I'll take the steps you mentioned and report back.

@david:

Yes, the pickups are wrapped in the infamous white tape.

[David Aubke]

When I plug into the harp directly, playing the keys does not produce any sound, but the lower half of the pickups do produce sound when tapped with a screwdriver.

That's a real puzzler. If the pickups respond to the screw driver, they should also respond to the tine. I wonder if the signal is just very weak.

If all three pickups in a parallel-wired set go bad, your entire circuit will die. I would put my money on at least one bad set somewhere in your piano except that you say you get some response out of the bass end. Unless the circuit can somehow be completed through an air gap or you've got a loose wire touching ground.

My experience with two white-tape pianos leads me to think you've almost certainly got some rewinding to do. Some others have expressed less distrust for those but I think there's a good chance I'll be rewinding every pickup the next time a white-taper comes through my door. I don't even trust the working ones to last.

[Ben Bove]

It may very well be the white pickup corrosion issue.  See the picture below, where the white-tape pickups wire corrodes.  with a tiny screwdriver, you can gently move the thin coil wire to see if it's broken away from the tab.

http://s3.photobucket.com/user/bjammerz/media/RhodesParts/Mk2PickupsIssueEdit3.jpg.html?sort=3&o=15

[Leaozinho]

Hi guys - I realize it's been a while but I had some things come up and haven't been able to put the time into this that I should have.  Anyway, I'm back on it now, slowly but surely.  In response to everyone's suggestions:

It doesn't seem to be an issue with the RCA connection.  No corrosion or bad connections as far as I can see.

When the harp is plugged directly into an amplifier, using the screwdriver I can get a response from the lower half of the keyboard's pickups.  Beyond that there is either no response or it is significantly weaker.  Playing the keys never produces any sound.  I've looked at the wiring around where the signal weakens and can't find anything really suspicious looking.  Maybe I just don't have the eyes for it but it looks OK to me. 

What should I try next here?  Alligator clips?  Should I take out a few pickups and test them with a multi-meter?  I guess my biggest problem right now is that I simply don't know what the problem is.

Again, thanks for your patience and help.  I really appreciate it.

[Ben Bove]

It is a very strange problem I have to admit.  I would think if you're getting a screwdriver tap noise, then certain pickups are active in order to amplify the screwdriver tap.  If you're playing notes on those same active pickups, those tines should be able to be heard.  The fact that no notes can be heard is interesting.

I will say that Mark II pianos have a propensity for pickup corrosion, and as mentioned by David, it's bad if a whole set goes out.

In order to help a little better, we'd probably need close pictures of the piano - specifically the pickups.  Very up close.  Make a note of where exactly you're no longer getting screwdriver tap noises, and take a bunch of pictures everywhere around there.  Cellphone video would be great too.  We're hoping to see the pickup wiring and where the coils are connecting as well.  You may also want to take pictures of the pickups standing from behind the piano, as the tonebars can get in the way visually, so we can see the wiring pattern and if there's any breakage.

Will perhaps make it easier for us as it's hard to troubleshoot this one in the dark.

[David Aubke]

Are your hammers striking the tines? Again, if the pickups respond to a screwdriver, they will also respond to the tine. If you can hear the screwdriver tapping but nothing when playing, the obvious answer is that the tines aren't even being struck by the hammers.

Other possibilities are that the pickup is adjusted too far from the tine or that you've never heard what an actual working pickup sounds like when tapped with a screwdriver and are declaring pickups to be good even though their response is quite weak. When the piano plays at a reasonable volume level (I understand you may not have that point of reference available), tapping it with a screwdriver should cause a substantial response through your amplifier. It's not just a slight clicking sound. If the screwdriver does not produce a startlingly loud sound, you're not really dealing with a functioning pickup.

[Leaozinho]

OK - here's a video and some pictures. 

I'd recommend watching the video first, because perhaps David is right in suggesting that I don't know the right sound to listen for.  My diagnosis was based on the fact that for the first half of the keyboard I DO get a click and some feedback when using the screwdriver, and then after a certain point (marked by the pencil-drawn 'X' shown in the video) I get nothing - no click, no feedback.  The video is here: https://www.youtube.com/watch?v=e_ixz_FIkME

Also in response to David - the hammers are most definitely hitting the tines.  Although my electrical knowledge is nil, I have restored a Rhodes before that didn't need any electrical repairs, so I have a decent understanding of the keyboards mechanics. 

Here is an album of pictures I took - these are all of the area where I stop getting any sound at all.  I apologize for the pictures' low quality - as you guys know, it's really hard to get in there and get decent pictures.  Let me know if you need me to do anything differently or give it another try. http://s296.photobucket.com/user/hankthemason/library/?sort=3&page=1

Thanks again for all the help. 

[David Aubke]

I think you've got a set of three parallel-wired pickups that are all bad or some other complete break in the circuit at your x-marks-the-spot. Clearly your bass pickups are responding but that's not the right sound. Should be a loud bang.

[Ben Bove]

Yes, you've got corroded pickup wire contacts.  I see mild corrosion in other parts of the piano pictures to validate.

I've pointed out the areas where the pickups go bad in your pictures below - what happens is the coil wire appears connected, but the actual point of contact has corroded through and it's just hanging together.  You should see a greenish ball at that arrow mark.  With a tiny flat head screwdriver similar to one you use to repair eyeglasses with, if you lightly move this wire you will quickly see bad pickups when the wire just breaks away from the metal tab.

You'll need to determine how many pickups need replacing by checking those thin wires around your "x" spot, possibly get a few extra as spares in case down the road you run into another 2 or 3 that go bad, and replace faulty pickups.  You've probably got a few in a series and that's killing the piano.  You can have the bad ones rewound if you like but it may be faster to grab a few quickly on ebay.







The standard red pickups will fit your piano, they don't have to be other white taped-ones.  there were a few different sizes, you'll want the 3" size.  Similar to the link below:

http://www.ebay.com/itm/WORKING-Original-Fender-Rhodes-PICKUP-SET-3-Set-of-5-/201332868475?pt=LH_DefaultDomain_0&hash=item2ee05fc57b

There is another method if you are very handy with a soldering iron - by dropping a ball of solder on the broken connection, you can bridge the connection gap between the wire and the metal bobbin.  However, I only recommend that for someone that is very handy as if you rest the iron on the pickup too long you'll melt the plastic around it.

[David Aubke]

bjammerz, I've got to dispute that a little bit. When I rewound 27 pickups from a 1981 Stage, they all showed corrosion at the center of the coil, not at the point near the solder terminal. Wish I'd taken a picture...

[Ben Bove]

That's really interesting, specifically because I've never seen them corrode anywhere else than at the solder terminal.  Was it in miserably corroded shape?

His first picture I reposted at the top looks rather thinned and green, that would be my best educated guess.  The best photo I have on the terminal corrosion below shows a shiny contact point vs. a green, corroded wire.  I'd be interested to see other spots

[David Aubke]

I'm going to review my photo archives tonight in case I have evidence somewhere. I've certainly seen them broken at that point near the terminal, which happens to be fairly close to the center of the coil as the wire runs. All I can say for certain is that when I reached the center of the coil removing the old wire, I thought to myself "well, there it is" because the first several wraps were clearly discolored.

[David Aubke]

For the record, I'm talking about a piano that came to me looking like it had fallen off a boat. Those pickups never stood a chance.

[Ben Bove]

That's interesting, only because I thought it was only where the wire came out of the shielding as it connected to the terminal.  Sounds good, let me know!

[Leaozinho]

Thank you for the help with the diagnosis.  So, just to be sure - the mark of a bad connection is going to be a thinned green wire?  I think I'm going to need to go out and buy a magnifying glass because I can't see the difference too clearly with just my eyes.

As another means of testing this, I should be able to use the alligator clip method to isolate specifically which pickups have a bad connection, correct?  Do you guys think that would be a good next course of action?

One more question - what exactly is the bobbin?  I'm not quite sure what you mean by, "by dropping a ball of solder on the broken connection, you can bridge the connection gap between the wire and the metal bobbin."  I tried looking up photos but still can't get a solid image of what part exactly the bobbin is.

[David Aubke]

Since a standard Seventy Three has its pickups wired in parallel sets of three, you can't test a single pickup with either a continuity tester or by bridging it with alligator clips. Within a single set of three, the signal can pass across any one of the pickups so shorting a single unit will tell you nothing. The only way to test a single pickup is to disconnect it from the circuit. On the other hand, jumpering across an entire set of three will indeed tell you if my diagnosis is correct. If all three in a set are bad, they create a complete break in the circuit and attaching the alligator clips so that they bypass the entire set can confirm this.

I think bjammerz mistyped. The bobbin is the main plastic body of the pickup. The part around which the wire is wrapped. The part he's talking about is the solder terminal or 'lug'.

[David Aubke]

And bjammerz, I'll bet the corrosion starts where you've suggested then spreads down the wire and that it was visually obvious at the center of the coil because it had already spread through several wraps that were all bunched together. Either way, the solder-blob fix is definitely an already-on-stage-for-the-gig last resort option.

[Leaozinho]

Great, I'll get some clips and let you know what I find.

David, when you say that the only way to test a single pickup is to disconnect it from the circuit, can you elaborate a little more on how to test the pickup?  Is it just a matter of testing it with a multi-meter?  Again, total novice when it comes to circuitry...

Thanks!

[David Aubke]

Yes, a standard multimeter. Just about every one has a resistance/continuity setting, typically indicated by a Greek Omega character on the function selector. Once the pickup is separated touch the probes to both solder terminals. Polarity is irrelevant - doesn't matter which probe touches which terminal. The multimeter should read somewhere in the neighborhood of 180 Ohms of resistance.

You can learn something about the condition of a set of parallel three. If you test across an entire set starting from either the north or south terminal of the first pickup to the opposite pole of the last pickup, you should see about 60 Ohms. If you don't, you know one of the three pickups is likely bad. Technically it's possible to have a combination of bad pickups that still end up reading 60 Ohms across the set but that's pretty unlikely.

[Ben Bove]

Yes sorry on the mis-type - the "metal tab" on the bobbin.

Where the little thin wire comes up from the coil, and attaches to the metal tab on the bobbin - that point that I circled, you can try moving the little wire with a tiny screwdriver and it should just break away from the terminal.  It looks connected but it's probably corroded all the way through and just hanging on by a thread.

[Leaozinho]

OK - finally got some alligator clips in the mail.  I apologize again for my ignorance on these matters, but I need some help moving forward.

Finally got some sound from the keys below the "X" mark from the video I posted earlier (if you've been following this thread). 

Problem is, no matter how many pickups I short out, I can't get anything out of the keys above the "X" mark.  Does this mean that EVERY pick-up above the "X" is bad?  Is there something I'm missing here?

One more huge newbie question: all this has been done with the sound coming straight out of the harp.  If I try to use the  1/4" jack on the front of the keyboard, I don't get anything.  Is this normal? 


EDIT:  I've also tried testing out various sets with a multi-meter, but I can't get any steady readings, and the readings I do get tend to be well over 100 ohms.  Is there a particular way to make the connection that I'm not doing?  I'll hold the tips to the bottom end of the first pickup and top and of the third pickup in a set of three and if the numbers ever stop jumping around for a second they tend to be well over 100 ohms.
Thanks again guys, don't know what I'd do without your help.

[David Aubke]

Gotta guess there's a short to ground at the X. That would allow the circuit to complete and would bypass the rest of the pickups.
In the video, the tone bar above that pickup looks a little wonky. If that tonebar is contacting the pickup bus wire, it can short to ground.

[Leaozinho]

Gotta guess there's a short to ground at the X. That would allow the circuit to complete and would bypass the rest of the pickups.
In the video, the tone bar above that pickup looks a little wonky. If that tonebar is contacting the pickup bus wire, it can short to ground.

The tone bar is pretty far from the bus wire - definitely no contact.  Any other possible cause for this weird behavior?

[David Aubke]

I just confirmed that a set of three pickups should read about 60 ohms. Truth is, if you test across any two pickup terminals of opposite poles, you should see about 60. That is excepting the first set of four at the bass end. Those should read about 45 (180 / 4). Mine read 44.2.

Seems like there's got to be a short to ground somwhere where the last working pickup meets the first non-working pickup.

[Leaozinho]

So after becoming incredibly frustrated with the rhodes, I think I'm just going to buy some new pickups and go from there.  I was looking on ebay and came across this sale:

http://www.ebay.com/itm/Fender-Rhodes-Piano-PICKUP-3-Set-of-5-Working/111654642380?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D30426%26meid%3D2d1964bf46b0434ab3a25a24d9271406%26pid%3D100005%26rk%3D1%26rkt%3D6%26sd%3D351380894541&rt=nc

Do these look alright? I'm apprehensive because they're so cheap.  Thanks guys!

[Ben Bove]

These pickups are the right size, and good era that don't fail from wire corrosion.

[Leaozinho]

Okay, here is the latest update. 

I got some new pickups from ebay, to replace that set of three that I knew for sure was bad.  I got the pickups off and they were indeed dead.  I tested the new set - everything was working.  Soldered them in.  Here's the result:

Now when the rhodes is plugged in I get a very faint sound from the keyboard, much fainter than it should be.  So totally confused, I tried doing some of the short-out experiments I was doing before.  Lo and behold, shorted to the ground from certain notes, I get a full-volume sound from the keyboard.  Going up the keyboard, shorting from certain notes will give me full sound, but shorting from other notes gives me nothing.  So I'm thinking I just have a whole lot of bad pickups.  Does that sound reasonable?  Would having a bunch of bad pickups in the upper register (I'm thinking 20-30) result in the volume being lower for the entire keyboard?  Any other thoughts on what's going on here? 

Let me know if I didn't explain this well enough and I'll try again - as you guys know I'm nowhere near the level of knowledge that y'all are.

Thanks!

[Ben Bove]

It may not be a lot of bad pickups - it actually could only be one or two, or perhaps a set of 3 that are cutting out the output.  When you're shorting the pickups lower on the piano and getting full volume, then you know contact is good up to that point.  I would try to determine at what point, going from left to right, that you find the volume cutting down.  When you find that point, really check that set of pickups for the small wire that comes from the coil and connects to the metal tab at the back, where the arrow denotes in the pictures above.  I can almost guarantee a couple have the wire corroded away.

I assume you're on the right path, that it has to do with the pickups.  I don't believe you're too far away from getting them figured out though.

[Leaozinho]

After replacing that group of three, I moved the short wire up the keyboard (left to right) - doing this I was able to get sound out of the next three keys, then another dead one.  I took that pickup off and it was dead, so I replaced it and was now getting sound up until that point.  Did the same thing, found another dead note 2 notes away and replaced that one.  Now I'm out of replacement pickups, but judging by how many notes are not making sound as I move left to right, I'm thinking I do indeed have quite a few bad pickups in the upper register.  This isn't really what I bargained for but at least I'm learning something, although I'm still totally confused as to why without a jumper cable I'm only getting very faint noise from the piano. 

[Leaozinho]

Also, I wanted to ask a quick question about pickup replacement.  What do you guys typically do when you are replacing a pickup and end up with a lot of slack in the bus wire?  Do you just leave it with the slack or do you snip it and solder each end on? 

[Ben Bove]

A little bit of slack is needed when you're sliding pickups closer or farther away, so it doesn't pull on a tight wire as you move them around.