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Discussion Starter · #1 ·
Hello all,

All of a sudden I noticed that something is wrong with the middle pickup on my Ibanez UV7 Green Dot. They are all the original Blaze II pickups. I've owned the guitar since the 90s so no idea when or how it might have happened but I think recently and all I've done recently is a setup for a different gauge strings so messing around with the bridge, tremolo springs, etc.

Anyway, the middle pickup sounds very thin and weak. If I touch a screwdriver to any of the pole pieces it make a lot of sound though. I plugged a cable in and measured tip/sleeve for all switch positions and this is what I got rounded off.

Pos1 (Bridge) 15
Pos2 6
Pos3 .5
Pos4 6
Pos5 15

Do you think the middle pickup is broke or is it something else?

Thanks for any help! Cheers,
Howie
 

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I agree, the middle pickup has failed, that resistance reading is far too low, there is a short circuit in the coil winding, to double check open the guitar and take a reading directly from the pickup lead.
 

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Discussion Starter · #4 ·
Argh, not the news I wanted to hear. Thanks though :) Just put new strings on so I'll get to it sometime. Luckily I don't use it anyway except when I'm messing around.

Lucky replacements look to be still available. Or maybe I should have it rewound? Are the new ones just as good, anyone?
 

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pickups usually don't simply fail. They usually have to have some sort of movement or damage. Typical failure comes from the enamel wire being damage and shorting, or one of the leads of the pickup has come undone internally. if you haven't rough handled your guitar or recently done any work to the other pickups it is unlikely that the pickup is bad.

Since the guitar is older it seems more likely that your switch is starting go out. it is possible that it isn't making good contact in position three. You can try some deoxit/ electronic cleaner , but it seem likely that the contact has simple started to pull away from the switch. You can try wiggling the switch selector a little to see if you get excess static/popping or if the pickup actually starts working.
 

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Switch failure doesn't make sense, how would you get a very low resistance reading from a bad switch?
he said he was measuring through the switch not the individual pickups. That said if that is not the case, and the actual pickup itself measures weak when you just measure the pickup by itself without anything else and it is weak, then it does sound like a pickup problem. You can send that pickup back to dimarzio and they will fix it. I have had to send in pickups a couple of times and Dimarzio is always amazing about getting the pickup fixed quickly and getting it sent back.
 

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First thing I would do is spray electronics cleaner in the switch & work it back & forth. If that doesn't work take a look at the solder joints. Pickups seldom fail. Could be a bad switch as well. Those ibby 5 ways are generally not considered as reliable as the fender type switches.
 

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Please let us know how you get on, despite all the insistence here there's absolutely no possible way a duff switch will give you such a low DCR of only 0.5k in position 3, it has to be the pickup.
Sorry, but in the immortal words of Judge Judy, if it doesn't make sense then it isn't true.
 

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Discussion Starter · #12 · (Edited)
Thanks everyone. Just got home and going to try contact cleaner first. The switch was scratchy about a year ago when I started using the guitar regularly again after it had been sitting a long time. But that scratchiness went away after a few uses. Same with the knobs.

I've never taken the pickguard off actually. I just realized I can keep the strings on there and remove the trem by removing the springs and then take the pickguard off...which will be easier.

It hasn't had any rough handling. The only thing is I changed string gauges so I had to do a full setup again. At one point I didn't have the tension right and the springs popped off and banged around in the tremolo cavity...was loud! But I doubt that would do anything to the rest of the guitar.

I'll keep ya posted, thanks again!
 

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Discussion Starter · #13 ·
Looks like I'm after a switch. I de-soldered the neck pickup, and tested it...reads 8 - 9...the reading kind of keep going up.

I found the schematic and it looks like everything is still connected where it should be. The fact that the bridge and neck pickups are fine would probably mean everything else is OK right, so it would be down to the switch since the pickup tests fine?

I'm so glad the same switch is still available...and only around $15. I'd rather just fix it now but it looks difficult to get apart? Part number is VLX53


 

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...I noticed that something is wrong with the middle pickup...the middle pickup sounds very thin and weak.

Do you think the middle pickup is broke or is it something else?
I de-soldered the neck pickup, and tested it...reads 8 - 9...the reading kind of keep going up.

The fact that the bridge and neck pickups are fine would probably mean everything else is OK right, so it would be down to the switch since the pickup tests fine?
But....it's the middle pickup that wasn't working?!? :confused:
 

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I just realized I can keep the strings on there and remove the trem by removing the springs and then take the pickguard off...which will be easier.
That's the way I've always done it.

...wedge the trem and unbolt the neck to remove the pickguard without removing the strings.
That works really well for some guitars, but with these, just pull the trem unit. Which is apparently what he already did. :)
 

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Looks like I'm after a switch. I de-soldered the neck pickup, and tested it...reads 8 - 9...the reading kind of keep going up.

I found the schematic and it looks like everything is still connected where it should be. The fact that the bridge and neck pickups are fine would probably mean everything else is OK right, so it would be down to the switch since the pickup tests fine?

I'm so glad the same switch is still available...and only around $15. I'd rather just fix it now but it looks difficult to get apart? Part number is VLX53


Yeah those things are not made to be repaired. Replacing the switch is easy enough. One word of advice from personal experience. Although it may not seem like it at the time, it's easier to desolder the leads to the output jack than to try to do it connected. Those teeny tiny leads are easy to break!
 

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Discussion Starter · #18 ·
But....it's the middle pickup that wasn't working?!? :confused:
Yes, I accidentally typed that I pulled the neck pickup. I meant I pulled the middle pickup and measured it. It was late and I was tired haha.

And yup I just left the string locks in tact and removed the trem to get the pickguard off. Was easier than I thought! I used to hate dealing with those springs but I must be used to it now!
 

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Discussion Starter · #19 ·
This is doing my nut in, middle pickup only should read about 13.5k, not 0.5k, not 8k, not 9k.
All you have to do is wedge the trem and unbolt the neck to remove the pickguard without removing the strings.
Hehe, don't know what to tell ya. I put the tester on it 3 times and each time it jumped up to 8 real quick and then kept climbing slowly. I did check the DiMarzio website and saw that it is supposed to be higher than that, but they also state the Bridge and Neck should be in the 20+ region and mine measure 15 at the output jack.
 

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Discussion Starter · #20 ·
BTW, Can any of you fine fellows tell me what the heck this wiring is? Its a thin round disc stuck on the bottom of the control cavity and then the two wires go to the top of the volume pot.

I found the vai wiring schematic on DiMarzio's site and everything seems to follow it exactly. However I don't see this thing there or in any of my other web searches.

https://drive.google.com/file/d/1vUtES_TmrmDkchzedzW7VqBGj7nObzXI/view
 
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