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Hf100r contact block

Posted: Tue Aug 18, 2015 5:08 am
by crm114
Hello,

Having a scanning issue with this jukebox. Seems that a few selections on one side of the mech dot want to play. The mech starts but doesn't find them and continues to scan.

Pinbank has been cleaned. The contact block cleaned too. Contact block pins move as they should. I have noticed that while scanning, slight upward pressure on the block will get those selections to work.

Is there an adjustment I missed? Is there something I should look for?

Re: Hf100r contact block

Posted: Tue Aug 18, 2015 2:52 pm
by Rob-NYC
I have noticed that while scanning, slight upward pressure on the block will get those selections to work.


This often indicates wear on the Bakelite contact block sliders. I have a couple of those blocks here that were removed due to that same problem. The sliding points develop flats and this lowers the whole block -often at an angle.

Rob/NYC

Re: Hf100r contact block

Posted: Tue Aug 18, 2015 4:16 pm
by Ron Rich
Most often this indicates that the phonograph has been transported, on it's back, without the proper two "thumb screws" and blocking installed. For some reason, unknown to me, this is a very common occurrence in a model R. The "usual fix" for this is to "re-form" both of the bent "arms" that drive the contact block, and make sure the contact block now rides firmly within the "U shaped", spring assisted, holder. One other thing can cause this type of a problem--If the SA Unit has been "rebuilt" and one or more pins installed backwards, or is slightly "bent", the sensor will not contact that pin. Ron Rich

Re: Hf100r contact block

Posted: Tue Aug 18, 2015 7:15 pm
by crm114
When I moved it I removed the mech and electronics. However no telling how it was moved in the past.

I noticed that the sheet metal extension on the back of the arm did look slightly bent down. Removed it from the arm and straightened it a small amount.

Will report later if that helps.

Is there a recommended lubricant for the contact block channel? Didn't see anything in the manual

Re: Hf100r contact block

Posted: Tue Aug 18, 2015 7:32 pm
by Ron Rich
If it looked bent--it IS bent--frog must sit at least 3/4 of the way into the U----2/3rds is better ! Caution--"arms" snap easily, when pressure is applied ! Lubricate only, with an extremely light coat of a graphite based grease--or no lube at all--Ron Rich

Re: Hf100r contact block

Posted: Tue Aug 18, 2015 7:56 pm
by MattTech
Ron Rich wrote:Most often this indicates that the phonograph has been transported, on it's back, without the proper two "thumb screws" and blocking installed. For some reason, unknown to me, this is a very common occurrence in a model R. The "usual fix" for this is to "re-form" both of the bent "arms" that drive the contact block, and make sure the contact block now rides firmly within the "U shaped", spring assisted, holder. One other thing can cause this type of a problem--If the SA Unit has been "rebuilt" and one or more pins installed backwards, or is slightly "bent", the sensor will not contact that pin. Ron Rich



Jeeze, Ronnie, you seem to "know it all", smarty pants. :)

Re: Hf100r contact block

Posted: Tue Aug 18, 2015 8:26 pm
by Ron Rich
Hi Mattie,
Yup--after almost 50 years of workin' on em--I shoulda otta learnt something ??
However, just to calm your fears, I'm still willing to learn more !
Ron Rich

Re: Hf100r contact block

Posted: Wed Aug 19, 2015 1:10 am
by MattTech
Ron Rich wrote:Hi Mattie,
Yup--after almost 50 years of workin' on em--I shoulda otta learnt something ??
However, just to calm your fears, I'm still willing to learn more !
Ron Rich


We all continue learnin', right up to the pine box. :shock:

Re: Hf100r contact block

Posted: Wed Aug 19, 2015 2:08 am
by Ron Rich
Matt,
It would be nice if that were true--however, there are people who think they "know it all", and therefore never learn anything new--
Ron Rich

Re: Hf100r contact block

Posted: Wed Aug 19, 2015 7:24 am
by MattTech
Ron Rich wrote:Matt,
It would be nice if that were true--however, there are people who think they "know it all", and therefore never learn anything new--
Ron Rich


Oh, you mean like me, eh?
LOL!

But seriously speaking, I, like you, have been in "the business" long enough to become a well-respected and well-recognized authority in my field.
And three times in the past 2 weeks, various people have called me a "dying breed", which I can honestly agree with.
Word's spread, and it seems the whole eastern coast is devoid of service techs that do what I do.
But it's all good, I can't complain.

And now, back to our regularly scheduled program.... :lol:

Re: Hf100r contact block

Posted: Thu Aug 20, 2015 3:19 am
by crm114
After slightly bending the sheet metal extension on the arm the contact block is making contact again. All selections appear to be working properly. Thanks for the help.

Re: Hf100r contact block

Posted: Thu Aug 20, 2015 4:03 pm
by Ron Rich
Oh, NO !! :shock: --One should never "bend nothing", on a jukebox-- One "re-forms the yielding member" !
Glad you have it working -- Enjoy ! Ron Rich