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kyonpalm | Posted: Jul 25 2012, 01:12 PM | ||
Professional Amateur Group: ADMINISTRATOR Posts: 10,568 Member No.: 30,882 Joined: Oct 16th 2008 Location: Laniakea | Having some trouble with my beloved, but now-broken Kenwood turntable. Please help me diagnose and hopefully fix this excellent machine!
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Tuskano | Posted: Jul 26 2012, 12:02 AM |
IDW Supremo Member Group: Advanced Members Posts: 914 Member No.: 38,740 Joined: Jun 29th 2012 Location: Guam, Earth | Not too keen on the insides of turntables myself, but like the guy in the comment of your video said, it might be the stopper/switch. The motor seems to be fine from watching it. It just needs whatever is telling it to stop/go to tell it that at the right time. I don't see any wires or sensors near the stopper/switch, but if there were any, I would think adjusting the switch to be longer or shorter to get it in range of the sensor would have done the trick. Of course, this is a proffesional opinion coming from a mechanic who has no place really to be working with wires so I may be wrong. lol If you ever really wanted to take the motor off (which I don't think you don't need to ), I would recommend EzGrip which we use at work for tight or worn screws. This post has been edited by Tuskano on Jul 26 2012, 12:02 AM |
kyonpalm | Posted: Jul 26 2012, 03:00 AM | ||
Professional Amateur Group: ADMINISTRATOR Posts: 10,568 Member No.: 30,882 Joined: Oct 16th 2008 Location: Laniakea |
You're right, there are none. I did think it was something to do with the stopper at first, but couldn't find anything that made that theory work... at least in my amateur opinion. Thanks for the advice! If it is indeed something other than the motor, I have a feeling I won't be able to fix it myself, since I'm not yet good with circuitboards... | ||
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Mazda ina Ford guy | Posted: Jul 28 2012, 02:39 PM |
333 Half Evil Group: Advanced Members Posts: 507 Member No.: 37,098 Joined: Mar 9th 2011 Location: The Twin Cities | I think Tuskano is on the right track, the stop switch (I suspect there is one) may be on the carriage the arm rides on (check the bottom), or at the end where it stops. Your 45 spacer may have tweaked it. And for God sake stop running the motor with the belt stoped, you'll put a "flat spot" on the belt. If you have run it more than a few minutes like that you should replace it, it is a delicate system, flat spots will throw off your arm speed as it progresses across the disc. Good luck hope you can figure it out. [ Post made via Mobile Device ] |
THE_HONDA_CG2 | Posted: Jul 28 2012, 02:50 PM |
Patient Zero Group: Advanced Members Posts: 4,279 Member No.: 37,947 Joined: Oct 1st 2011 Location: Update Profile | We've talked about this prior to the creation of this thread. If you really want to get under those screws you'll have to use a vice grip or pliers to get at them since the screwdrivers that you've tried strip the screws in question. Vice grips are a manlier version of pliers so if you've tried my plier recommendation then my next course of action would be to step it up and use a vice grip. I wish you the best of luck with figuring this out! Hopefully we'll see the Kenwood up and running sometime soon! [ Post made via Mobile Device ] |
Möbius | Posted: Jul 28 2012, 04:17 PM |
IDW Top Poster Group: Advanced Members Posts: 33,844 Member No.: 3,524 Joined: Oct 2nd 2004 Location: Update Profile | Do not remove the motor, it is not your problem here. The problem is with the control of the motor, which I am not familiar with. It is most likely switches as there does not seem to be feedback circuit of any sort. I have no access to the schematics, but there has to be a way so it knows : a ) Home position, b ) Start position for a 33, c ) Start position for a 45, and d ) End position. It looks like on power up it tries to make sure it is in home position ( so user can load a record ), but since it never confirms it, it keeps running. And if you really want to remove the motor, it is most likely not a Phillips head, but a Pozidriv, which you most likely don't have any way. Also, it is most likely epoxied into place, so it will be really tough to remove. Edit : No, maybe I am being stupid.... The thing that looks like a fan under the circuit board, is probably what it uses to count revolutions. In that case, there is either only a zero switch, and then counts revs, in which case you have to find the switch... Or get ready for the worst... It detects Home position by motor current. I am not prepared to make that call yet. Please post a pic of whatever is underneath that small circuit board next to the motor. This post has been edited by Möbius on Jul 28 2012, 04:34 PM |
kyonpalm | Posted: Jul 28 2012, 04:41 PM | ||||||
Professional Amateur Group: ADMINISTRATOR Posts: 10,568 Member No.: 30,882 Joined: Oct 16th 2008 Location: Laniakea |
Actually, after removing and replacing the belt, it moved with the wheel, so it won't be rubbing a flat spot anymore.
Brilliant deduction, Möbius! I had this confirmed to me by a master of electronics just yesterday. This is what he had to say:
Since he's on vacation in Greece at the moment, he cannot give me a definite set of instructions until he's back home and can find the schematics. Looks like a repair might be possible! In the meantime, I've gotten another turntable. This one I'm really excited about, since it is one of my favorite brands - a Technics SL-Q200: Image size reduced, original size: 900 x 600. Click here to view the image in its original dimension. That's not my pic, it's the eBay seller's. Should arrive here early the week after next. EDIT: To Mobius' edit - I will try to dismantle it and get better pics tonight. This post has been edited by kyonpalm on Jul 28 2012, 04:42 PM | ||||||
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Möbius | Posted: Jul 28 2012, 04:45 PM | ||||
IDW Top Poster Group: Advanced Members Posts: 33,844 Member No.: 3,524 Joined: Oct 2nd 2004 Location: Update Profile |
I ninja'd you. Check my edit above. The opto encoder he is talking of is the black fan thingie I was posting about. If you post a pic of what is under that circuit board, the black fan thingie and whatever else is under there, I can probably confirm. | ||||
Mazda ina Ford guy | Posted: Jul 28 2012, 05:35 PM |
333 Half Evil Group: Advanced Members Posts: 507 Member No.: 37,098 Joined: Mar 9th 2011 Location: The Twin Cities | Looks like you've covered your bases, mad props for spinning actual vinyl! [ Post made via Mobile Device ] |
Möbius | Posted: Jul 28 2012, 06:08 PM |
IDW Top Poster Group: Advanced Members Posts: 33,844 Member No.: 3,524 Joined: Oct 2nd 2004 Location: Update Profile | Come on, get the pic, this might be an easy fix, unless it detects by motor current. |
kyonpalm | Posted: Jul 29 2012, 04:02 AM | ||||||
Professional Amateur Group: ADMINISTRATOR Posts: 10,568 Member No.: 30,882 Joined: Oct 16th 2008 Location: Laniakea |
Sorry, I just got around to it now. I wanted to get video as well. Here are some pictures of the cluster of parts in question... Image size reduced, original size: 4000 x 3000. Click here to view the image in its original dimension. Image size reduced, original size: 4000 x 3000. Click here to view the image in its original dimension. Image size reduced, original size: 4000 x 3000. Click here to view the image in its original dimension. Image size reduced, original size: 4000 x 3000. Click here to view the image in its original dimension. Image size reduced, original size: 4000 x 3000. Click here to view the image in its original dimension. Image size reduced, original size: 4000 x 3000. Click here to view the image in its original dimension. That black piece connected to the circuit board in the last couple pictures is part of the opto encoder (the fan-like thing spins in the opening.) Here is a picture of the underside of the tonearm unit, as requested: Image size reduced, original size: 4000 x 3000. Click here to view the image in its original dimension. There doesn't seem to be anything in it that would directly indicate when the unit has reached its end point. Here is the video...
Thanks. I'm a big fan of the format and have been collecting records for a couple years now. For the past year, I've pretty much ignored buying CDs entirely. The satisfaction that comes with the superior packaging and playing experience is wonderful and you don't get that with any other format. | ||||||
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HorizontalMitsubishi | Posted: Jul 29 2012, 09:21 AM |
Part of the Tessou Signature Series Group: Advanced Members Posts: 2,439 Member No.: 2,022 Joined: Jun 16th 2004 Location: Torrance California | What I'd try is to put the light sensor back into place, and unloop the drive cable off of the white spool and turn it on and see if it's able to count enough rotation to find it's "home" position then put it all back together and see if it runs. |
Möbius | Posted: Jul 29 2012, 04:41 PM | ||
IDW Top Poster Group: Advanced Members Posts: 33,844 Member No.: 3,524 Joined: Oct 2nd 2004 Location: Update Profile |
Good suggestion, but at the same time I would be surprised if the unit references everything off of that. What's that in the yellow circle? | ||
kyonpalm | Posted: Jul 29 2012, 04:48 PM | ||
Professional Amateur Group: ADMINISTRATOR Posts: 10,568 Member No.: 30,882 Joined: Oct 16th 2008 Location: Laniakea |
Not 100% sure, since I couldn't lift the arm unit out completely. To do that, I would have to uncoil the drive wire like HorizontalMitsubishi said. I'll do that next chance I get, but that might not be for a little bit. Bear with me, I'll have pics of that up as soon as I can get them this week. | ||
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Möbius | Posted: Jul 29 2012, 04:49 PM | ||
IDW Top Poster Group: Advanced Members Posts: 33,844 Member No.: 3,524 Joined: Oct 2nd 2004 Location: Update Profile |
Just asking since it is on the bottom of the unit and has two wires connected to it. Might be something to pick up the home position, hard to see in the pic. | ||
HorizontalMitsubishi | Posted: Jul 29 2012, 09:10 PM |
Part of the Tessou Signature Series Group: Advanced Members Posts: 2,439 Member No.: 2,022 Joined: Jun 16th 2004 Location: Torrance California | I didn't notice that previously, but I think that might be the sensor that looks for the home position. |
kyonpalm | Posted: Aug 1 2012, 07:58 AM | ||
Professional Amateur Group: ADMINISTRATOR Posts: 10,568 Member No.: 30,882 Joined: Oct 16th 2008 Location: Laniakea | Okay, the whole thing has been fixed. Big thanks to HorizontalMitsubishi for making me think to look under the tonearm unit and also thanks to Möbius for working the last kinks in the system out with me.
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Wanderer | Posted: Aug 1 2012, 02:50 PM |
The Watcher Group: Advanced Members Posts: 914 Member No.: 35,816 Joined: Jun 24th 2010 Location: San Jose, CA | Doesn't it feel good when you can fix something yourself that you originally didn't think you could? [ Post made via Mobile Device ] |
kyonpalm | Posted: Aug 1 2012, 03:11 PM | ||
Professional Amateur Group: ADMINISTRATOR Posts: 10,568 Member No.: 30,882 Joined: Oct 16th 2008 Location: Laniakea |
Though like I said, I have Möbius and HorizontalMitsubishi to thank for helping point me in the right direction. | ||
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Möbius | Posted: Aug 1 2012, 05:01 PM |
IDW Top Poster Group: Advanced Members Posts: 33,844 Member No.: 3,524 Joined: Oct 2nd 2004 Location: Update Profile | Actually it was Mazda in a Ford Guy who asked to see the underside... |
kyonpalm | Posted: Aug 1 2012, 05:06 PM | ||
Professional Amateur Group: ADMINISTRATOR Posts: 10,568 Member No.: 30,882 Joined: Oct 16th 2008 Location: Laniakea |
Oh shoot! My apologies, Mazda in a Ford Guy! | ||
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Mazda ina Ford guy | Posted: Aug 2 2012, 05:30 PM |
333 Half Evil Group: Advanced Members Posts: 507 Member No.: 37,098 Joined: Mar 9th 2011 Location: The Twin Cities | No offence taken! Glad to see you got it working. [ Post made via Mobile Device ] |