Issue(s) with Kenwood KD770D

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Maritan

Issue(s) with Kenwood KD770D
« on: 8 Feb 2013, 05:32 am »
Hello all,

As some of you might know, I recently bought a Kenwood KD 770D from someone on Audiogon.

I downloaded the instruction manual from Vinyl Engine and started setting up the TT. When I push the UP/ DOWN button however, nothing happens. Nothing moves.

To make sure that there was power, I put the tone arm in its rest and pushed the start button. Sure enough, the platter started spinning. So, obviously I have power, but no UP/ DOWN functionality...

Anybody have any insight on what the issue could be? What exactly does this button do? My understanding is this is what places the tonearm down on the record? What part should I see move that affects the height of the tone arm?

Any help would be much appreciated.

Thanks!

S Clark

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Re: Issue(s) with Kenwood KD770D
« Reply #1 on: 8 Feb 2013, 05:36 am »
Why not just operate the tonearm manually?  Unless you have really shakey hands, there shouldn't be an issue.

usp1

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Re: Issue(s) with Kenwood KD770D
« Reply #2 on: 8 Feb 2013, 06:19 am »
Did you try moving the arm to the start of the LP and then press up/down. I am not sure if it is similar to my Denon but the up/down on mine works only when the arm is over the LP.

Nick77

Re: Issue(s) with Kenwood KD770D
« Reply #3 on: 8 Feb 2013, 10:49 am »
It wouldn't be uncommon for certain functions to not work on a 30yr old deck.  :scratch:

MaxCast

Re: Issue(s) with Kenwood KD770D
« Reply #4 on: 8 Feb 2013, 11:08 am »
It wouldn't be uncommon for certain functions to not work on a 30yr old deck.  :scratch:
that is what we are trying to find out, no?

neobop

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Re: Issue(s) with Kenwood KD770D
« Reply #5 on: 8 Feb 2013, 12:09 pm »
The up/down button works the cueing mechanism, independently of the platter. Is your arm stuck in the up or down position, or actually stuck?  Can you play a record?  There is also a sensor and mechanism that lifts the arm at end of record. This mechanism only raises and lowers the arm with the cueing, there are no cams or mechanical junk attached to the arm.

I'll look in the service manual (did you download it?) for troubleshooting.  In the mean time, maybe you just have to adjust the cueing mechanism.  You need a small allen wrench. From your description, I'm not sure if it's actually broken. The table was advertised as being in perfect working order, but before you take it up with the seller, check it out.  Once the power is on, you can work the cueing whether the platter is spinning or not.  Hope it's just an adjustment.
neo

orthobiz

Re: Issue(s) with Kenwood KD770D
« Reply #6 on: 8 Feb 2013, 02:23 pm »
That is a gorgeous turntable! It appears to me that the cueing is controlled electronically with the button and there is no lever at the tonearm. So, without having looked at the schematic and having no independent knowledge of this particular model I would suggest:

Unplugging the unit.
Securing the tonearm.
Taking off the dustcover.
Removing the platter.
Turning the turntable on its side.
Take off the bottom.
Look for the button, spray Deoxit on any contacts you can see.
Make sure the wires from the button are attached to wherever they attach, maybe even at the base of the arm's underside.

If there is some kind of metal/plastic cog looking gear thing, try to turn it gently with your fingers. Sometimes these things are stuck and simple manual manipulation will work. I don't know if the arm lift up/down is powered by a separate little servo at the arm or some kinda gear thing that needs the platter spinning.

Good luck!

Paul

Maritan

Re: Issue(s) with Kenwood KD770D
« Reply #7 on: 8 Feb 2013, 03:47 pm »
As Neobop mentioned, this TT was advertised as good working order. That would mean everything works including the UP/ DOWN switch.

As Neobop also mentioned, this UP/ DOWN assembly is independent of the platter. So, it should raise/ lower without the platter turning. Just in case this was not true, I tried what usp1 suggested, but that didn't help.

Neobop, Orthobiz and others:

Just to clarify, I can manually move the tonearm back and forth without any issues. What appears to be non-functional is the elevator assembly. My guess is because it is stuck in the UP position. I have attached a picture of what I believe is the elevator assembly.



I cannot play a record because if I move the tonearm over the LP and push UP/ DOWN nothing happens. The cartridge hangs about 5mm over the LP in the air does not make any contact with the LP. I did go through the whole set up process as described in the manual, but since the elevator mechanism does not lower, I doubt my "set up" is valid - the manual asks to lower the elevator arm before setting counterweight etc.

Where is the sensor located that tells the arm to go up? I have allen wrenches. I see in the manual how to adjust the tonearm height. But, I think have a more basic problem, because they say to adjust the height after the arm elevator lowers.
 
I have already downloaded the service manual and I'm looking through it to see if I can spot anything that will help.

I can be fairly mechanically/ electrically inclined, but this is my first TT, so please feel free to assume I'm stupid and overlooking something very basic.

roscoeiii

Re: Issue(s) with Kenwood KD770D
« Reply #8 on: 8 Feb 2013, 04:11 pm »
While you fiddle with the up/down mechanism, is it possible to remove the cueing device to be able to manually use the table in the meantime?

neobop

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Re: Issue(s) with Kenwood KD770D
« Reply #9 on: 8 Feb 2013, 04:27 pm »
Maritan,
There are 2 allen fittings to adjust arm height. They are on the baseplate, or just above.  1 faces the outside and the other faces the back.  I'm not sure what size these are, but it's the same as used on most arms of that era, like Linn or Alphason, Zeta etc.  If you're not used to doing this adjustment, you might want to remove the cart/headshell first.  It's easier if you have 2 allens so you can leave them in while you make the adjustment.  You have to hold the housing and physically move it up or down and and hold it when you tighten the fittings.  It's a little tricky, it doesn't move that easily, and you have to keep it straight (level) when you tighten.

Earlier I said the cueing was an allen fitting.  I forgot, it's a small straight screw head located just under the front of the cueing mechanism.  You have to get down on arm level to really see it. 

As I said, there are no cams or plastic thingies attached to the arm. The cueing button is hooked up to the same IC as the motor, which in turn is connected to the cueing servo. Maybe the button needs cleaning as Ortho suggests, or maybe it just needs height adjustment.
neo

P.S. I was about to post this when yours appeared. Find that little screw just under the cueing platform and see if you can lower it.  Maybe you can try it in full manual mode.  I don't know if it's the button or the servo, or maybe a disconnected wire, but it's sure not in the advertised condition. sigh  I think the guy said it's been in a closet for the past x number of years.  Now we know why. 

Maritan

Re: Issue(s) with Kenwood KD770D
« Reply #10 on: 8 Feb 2013, 05:44 pm »
I apologize in advance if I'm not using the terms correctly. Like I said before, please assume I'm stupid and suggest even the most basic things to ensure that I haven't skipped anything.

I'm sorry, but what is the cueing mechanism and what exactly does it do on this TT? How is it different from the UP/ DOWN function? I thought my own flesh and blood arm/ hand was the cueing mechanism and I was the one to cue the tonearm up with the LP?  :scratch:

From the manual, I have to physically move the tonearm to the lead-in groove and then, with the platter spinning, hit the UP/ DOWN button to lower the stylus on to the record. That tells me the only "mechanism" available on this TT is the mechanical lifting/ lowering. How would adjusting the height of the arm affect anything if the UP/ DOWN mechanism doesn't work at all? Am I missing something? Seems to me, the only thing I'd gain by adjusting the height is to make the TT manual instead of semi-auto and usable by allowing the stylus to touch the LP. Is that correct?

Personally, I feel that this is supposed to be a semi-auto TT, and I would strongly prefer that it work that way. Otherwise, I didn't receive what I paid for. I've contacted the seller and let him know that there's an issue with the TT, but I'm not bitching and moaning about it. Yet. Just trying to find out if everything was functional when he shipped it to me. I'm not hitting the panic button, but I'm not going to be a happy camper if I paid for a TT that doesn't work as advertised either.

It looks like I have some troubleshooting to do.

First, go through what Orthobiz said.

If that doesn't help, I'm going to have to start checking signals from and to the IC and ensure that things are actually communicated.

roscoeiii

Re: Issue(s) with Kenwood KD770D
« Reply #11 on: 8 Feb 2013, 05:57 pm »
"cueing mechanism"= any of the mechanical parts (lever,elevator assembly, etc) that are involved in raising the tonearm and lowering it onto the vinyl. So referring to your diagram, my question would be whether it is possible to remove the elevator assembly so that you can manually cue your tonearm. At least while you troubleshoot your problem.

orthobiz

Re: Issue(s) with Kenwood KD770D
« Reply #12 on: 8 Feb 2013, 06:25 pm »
It appears that the UP/DOWN button operates the cueing mechanism at the back of the tonearm manually. It's the little crescent shaped bar that holds the tonearm off the record when you manually bring the stylus/cartridge over the record you want to play. It's marked "elevator assembly" in the drawing you supplied. Something motorized/automatic happens at the base of the arm to make it lift up and down.

Take off the bottom and let us see the underpinnings of this magnificent table!

Paul

MaxCast

Re: Issue(s) with Kenwood KD770D
« Reply #13 on: 8 Feb 2013, 06:26 pm »
I would not be so inclined to remove or alter anything.  If it doesn't work, send it back, unless a course of action can be agreed to between buyer and seller.

roscoeiii

Re: Issue(s) with Kenwood KD770D
« Reply #14 on: 8 Feb 2013, 06:39 pm »
I would not be so inclined to remove or alter anything.  If it doesn't work, send it back, unless a course of action can be agreed to between buyer and seller.

Why is that? OP got a great deal and this mechanism won't affect playback if it can be disabled. I get the impression that OP would be hard pressed to find something better sounding at the price he paid.

simoon

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Re: Issue(s) with Kenwood KD770D
« Reply #15 on: 8 Feb 2013, 06:57 pm »




From what I see in the diagram, the portion marked 'Elevator Assembly" looks like a standard hydraulic tonearm lifter.

If so, can you put pressure directly on it and lower it? This would verify that it is an electric problem and not a mechanical problem with the hydraulic lifter itself.

Maritan

Re: Issue(s) with Kenwood KD770D
« Reply #16 on: 8 Feb 2013, 07:08 pm »
Guys, that stuff that's marked in red are MY annotations.  :lol:

The tonearm and anti-skate weight was marked just as an addition. The elevator assembly is a GUESS. I was hoping someone would confirm or deny that that crescent shaped deal is in fact the elevator assembly...  :thumb:

neobop

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Re: Issue(s) with Kenwood KD770D
« Reply #17 on: 8 Feb 2013, 08:05 pm »
You guessed right.  Your arrow is pointing at the platform of the cueing or elevator mechanism.



Notice the screw head in the center of the arm directly under the cue mechanism. Loosen that and see if you can lower the platform.

"How would adjusting the height of the arm affect anything if the UP/ DOWN mechanism doesn't work at all? Am I missing something? Seems to me, the only thing I'd gain by adjusting the height is to make the TT manual instead of semi-auto and usable by allowing the stylus to touch the LP. Is that correct?"

Sometimes when arm height is adjusted, the cue height also has to be corrected.  If the cue height is set way too high it can prevent the stylus from making contact with the record.  A common problem that can be easily overlooked is the cueing platform being too high and hitting the underside of the arm when in play.
neo

 





Maritan

Re: Issue(s) with Kenwood KD770D
« Reply #18 on: 8 Feb 2013, 08:29 pm »
Just got this message from the seller:

Quote
I ONLY HAD THIS UNIT A SHORT TIME SO IM NOT VERY FAMILAR WITH IT.I DID HAVE ALL FUNSIONS WORKING .I PLANED ON SETTING IT UP IN MY HOUSE BUT NEEDED MONEY FOR OTHER THINGS.ONCE YOU HAVE THE ARM BALANCED IT SHOULD WORK WELL AS WELL AS A NICE LOOKING UNIT.IM SURE ONCE YOU SPEND SOME TIME AND GET FAMILAR WITH IT IT SHOULD WORK WELL .

 :roll:

Looks like the seller will be no help in troubleshooting things. I'm wondering if I should go through the effort of troubleshooting this thing, or see if I should send it back?

Also, looking at your picture, Neobop, looks like the elevator mechanism on yours is lifted off the plinth. Well, mine is all the way down. I gently pulled on the entire assembly by holding on to the base of the elevator assembly, and the whole assembly slides easily upwards and when I release it, slides back down. Neobop - Are you able to do the same thing with your elevator assembly?

Not sure what this means now. So even with the elevator mechanism all the way down, the stylus does not make contact with the LP. Obviously there's some height adjustments to make.

But I really want to figure out the elevator mechanism too. According to the manual, the TT should power up in the UP position. Nothing of the sort is happening.

roscoeiii

Re: Issue(s) with Kenwood KD770D
« Reply #19 on: 8 Feb 2013, 08:31 pm »
Some photos of your tonearm and the underside of the table might help us troubleshoot this with you (says the worst photographer on the planet) .