8mm Forum: Help with my Chinon 9500 ...

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Posted by Osi Osgood (Member # 424) on January 30, 2017, 12:41 PM:

Hey folks, maybe you can help ...

Recently, my CHINON 9500 has developed a sound problem ...

Sound is only heard on playback ... (that's not the problem), but there is a very staticky sound, when I turn up the volume knob, I get a very high pitched squeal, for lack of a better wording, and it would at least seem that it is connected in some way to either some form of vibration in the projector or perhaps, something else failing ...

I also have on the "balance knob" (as this is twin track "stereo" model), this problem as well. I have to have on the volume knob, the "sharpness" or tone, without any sharpness or that horrible squeaky sound comes up. Note: it does not come up if I have the volume level very low.

any help folks?

Posted by Brad Kimball (Member # 5) on February 01, 2017, 10:35 AM:

Sounds like the sound head is going. I had a similar issue some years back and a friend in the electrical industry said it wasn't anything to do with wiring or output in the back of the Chinon 6000 I had back then. I ended up simply replacing it since I lacked the resources to acquire a new head nor the knowledge to install one. I didn't want to replace one bad head with another used worn out head from a "parts" machine.

Posted by Steve Klare (Member # 12) on February 01, 2017, 11:05 AM:

I've had something similar on my ST-1200. Through the internal speaker it's a squeal, you put it through an amp it becomes a "shriek"! (-sends the cats running for the basement in a hurry!)

In my case it usually comes down to one of the lesser used switches (track select or PA/ALC or record key) needing to be switched a couple of times to clean the contacts. (remember: most audio jacks are switches too.)

-could be something similar.

Posted by Osi Osgood (Member # 424) on February 01, 2017, 11:53 AM:

Thanks for the feedback so far.

Just to add some more info on the problem ...

The screeching sound is heard whether I use the magnetic or optical sound ...

I get the sound, whether I use the speaker in the projector, or plug the two RCA output jacks directly into my dolby sound amplifier ... [Frown]

Posted by Brad Kimball (Member # 5) on February 01, 2017, 08:29 PM:

O'h my goodness! Osi, my aplogies. I didn't realize what you had accomodated both optical and magnetic. Well, mine was strictly magnetic. I'm going to let Steve drive this rig. If you good fellows don't mind I'd like to ride along and learn a thing or two (or three) from Sirs Steve of Klare and Osi of Osgood.

Posted by Steve Klare (Member # 12) on February 01, 2017, 10:14 PM:

Well,

Mine is just a hunch: something that worked out for me once or twice in the past. It's one of those things you try out before you start major surgery because it costs you nothing. If it doesn't work, you are no worse off than before.

Personally I hate it when something like this happens here. My usual setup is two machines side by side. You'd think I'd at least limp along on the second machine or maybe swap the wounded one out and fix it later, but it bothers me enough I usually put all the films away and set the problem right.

You just don't get that involved when it's a toaster or a vacuum cleaner: you can easily grow to care about these machines!

Posted by Osi Osgood (Member # 424) on February 02, 2017, 11:39 AM:

I could, in theory, replace the sound heads as I have a second CHINON 9500 for spare parts, but i want to be absoluetely sure that it IS the sound heads before, as the Duke of Klare has, "major surgery".

I had noted on the last reply on this series, that I get the same "feedback" (probably a better way to describe it), whether I'm playing the optical or magnetic sound.

"Sir Duke of Klare' ... it has a nice ring to it! [Smile]

Posted by Steve Klare (Member # 12) on February 02, 2017, 12:54 PM:

-Nooooooo!!!

I pride myself on my good, solid peasant ancestry!

Not a drop of Noble blood among them: just good, honest, hard working people!

(We came here in steerage and we're cool with that!)

Posted by Osi Osgood (Member # 424) on February 02, 2017, 12:57 PM:

"Steerage" ?

So, you came atop a cow? [Smile]

Posted by Steve Klare (Member # 12) on February 02, 2017, 12:59 PM:

-probably next to the coal bunker, maybe even within it!

(Dad graduated from High School: there's a first time for everything!)

Posted by Brad Kimball (Member # 5) on February 02, 2017, 08:51 PM:

Rolling on the floor laughing!!

Posted by Steve Klare (Member # 12) on February 02, 2017, 09:04 PM:

So Brad:

-is any of this the thing or two you hoped to learn?

The conversation here sometimes free-associates, but we'll get there eventually!

Posted by Osi Osgood (Member # 424) on February 03, 2017, 11:53 AM:

I haven't received any help yet, though I have enjoyed the humor!

I'm glad that my Eumig 926 stereo still runs fine, though. those Eumig's are such great work-horses when it comes to projectors.

Posted by Steve Klare (Member # 12) on February 03, 2017, 11:54 AM:

Then the switch-trick didn't work?

-sometimes it doesn't.

It's still worth trying even if it only eliminates a possibility.

Posted by Brad Kimball (Member # 5) on February 03, 2017, 04:15 PM:

Yes. More importantly.. I'm having a ball just reading the comic banter between good friends. Isn't that why we're here? F-U-N with good people who share the same passion for a great old past-time.

Posted by Steve Klare (Member # 12) on February 03, 2017, 05:41 PM:

We do two comic banter shows a year in lovely Wildwood, New Jersey!

-Weekend long: 3 dimensionally and in person!

-Not particularly further from Highland Mills than I am right now! Take the Garden State Parkway until you (almost) can't take it any more!

(We keep trying to lure Osi in with lurid tales of immaculate Grizzly Adams prints, but so far without any success!)

[ February 03, 2017, 08:01 PM: Message edited by: Steve Klare ]

Posted by Andrew Woodcock (Member # 3260) on February 04, 2017, 02:20 AM:

As you say you get the same noise on magnetic films through your amplifier as you do optical films, I see little point in changing the magnetic head.

Almost 99.9999%, it will not be the culprit here.

Try a little deeper in the amplifier components themselves.

Posted by Osi Osgood (Member # 424) on February 04, 2017, 12:06 PM:

This is where we start to get into the realm of unknown for me.

With all my vast knowledge (so-called) of film prints and they're history, I know little on the repair or upkeep of projectors, beyond replacing lamps, knobs and sound heads. getting into the transistor and such, i'm completely lost and wouldn't know where to look.

Posted by Steve Klare (Member # 12) on February 04, 2017, 03:33 PM:

Things being what they are with these machines these days, in-depth circuit knowledge isn't all it's cracked up to be.

In a lot of cases there isn't enough information (schematics in particular), to help troubleshoot a board down to a bad component and fix it.

-so I do what everybody else does: replace the whole assembly and hope the "new" one isn't dead too!

Pat D'alessio and I troubleshot an accidentally silent 16mm machine about a year ago by e-mail, right down to a couple of shorted transistors in the power amp.

-the set of schematics he sent made all the difference. Other than that it's trying to find a town five states away without a map!

Posted by Andrew Woodcock (Member # 3260) on February 04, 2017, 04:35 PM:

Steve's solution is the best and easiest here Osi seeing as you have a "spares" machine, so long as it too, doesn't have a faulty amp rendering it a spare?

Posted by Andrew Woodcock (Member # 3260) on February 04, 2017, 07:05 PM:

The thing is Osi, to love film now at this late stage of the game, is to equally love learning all there is to know about our treasured machines, and exactly how to keep them that way.

Otherwise, it's goodnight Vienna once again, to yet another seasoned collector.

Its all out there, it just needs learning, digesting and implementing.

Once done, the hobby lasts forever if you so wish.

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