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Topic: Snap, crackle, pop!
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Paul Adsett
Film God
Posts: 5003
From: USA
Registered: Jun 2003
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posted September 16, 2008 09:52 PM
Hi Patrick, I have not seen too much discussion of Yashica's on this forum, the most popular projectors being Elmo's, Eumig's, and Sankyo's. But there are some real electronics experts posting here, so no doubt somebody will jump in to help you out.
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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj
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Osi Osgood
Film God
Posts: 10204
From: Mountian Home, ID.
Registered: Jul 2005
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posted September 17, 2008 12:42 PM
As an owner of this certin projector, I have a vested interest in seeing you getting this up and running.
My yashica (when it was up and running) had a lot of "snap crackle and pop", although I did like chasing those little cereal elves all over the dang house,
They squash nice!
OK, joking aside, mine does the same thing. Please note, that a lot of optical soundtracks sadly will have a certain amount of pop and static at places. Not all soundtracks have that. I have quite a few where they are crystal clear, but optical soundracks are somwewhat notorious for having that.
I never noticed the crackling on the magnetic soundtrack, except for when I was turning it up and down, lots of static on either soundtrack in those cases.
I agree with the others about cleaning those areas of the Yashica. This really is a nice little sound projector. I was always fond of how gentle this projector was on films AND how quiet it runs.
I have a question for you, Patrick. Were you able to get the lower front cover, (where all the switches are at), off? I've looked all over that projector and had no luck on finding a screw or spring or SOMETHING that will allow the lower front to come off, which is crucial, if you want to take out a burned out optical lamp for optical sound.
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"All these moments will be lost in time, just like ... tears, in the rain. "
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Martin Jones
Phenomenal Film Handler
Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008
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posted September 18, 2008 02:58 AM
Patrick,
That was the logical next step.. good thinking. Now you will have to check whether the noise is motor noise (i.e emanating from the motor itself) which could be carbon brushes if it's that kind of motor, or a failed suppressor in the motor supply line, or whether it is due to bad "grounding" of the motor or gearing in the projector mechanism. For the latter look for "grounding" straps to the projector chassis from the motor, poor continuity between the chassis and the amplifier ground, and any leaf springs bearing on rotating parts which ground any static charges. Such spings contacts should be removed(if possible), cleaned (and the surface they bear on) and replaced with a little more tension than before.
John (Black),
Your "Lube Job" sounds just like a "americanized" name for the "Electrolube" I use.... a switch cleaning fluid that removes dirt with a very light conducting lubricant that stays on the contact afterwards for smooth action. It is good on practically every kind of contacts, including high current relay or switch contacts; as the contact opens the lubricant stretches in the gap and then "breaks" cleanly and quickly
Martin.
[ September 18, 2008, 11:41 AM: Message edited by: Martin Jones ]
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Retired TV Service Engineer
Ongoing interest in Telecine....
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Patrick McGrath
Film Handler
Posts: 97
From: Huntington Beach, CA
Registered: Jul 2008
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posted September 21, 2008 01:29 AM
Thanks to everybody who has jumped in with advice.
I have a bit of an update.
First of all, I now know the Yashica P810 inside and out! I can disassemble that puppy in about three minutes flat.
Secondly, I have a whole new appreciation for the design of said unit. Nicely built with easy access to all circuits and gears.
However, I have not fixed my sound problem ![[Confused]](confused.gif)
I did successfully rebuild the speed control circuit, thereby removing my temporary bypass. Osi take note: The key component was the first two transistors in line(I'll get the replacement numbers for you later. It's late and I'm typing this on my laptop lounging in bed!)
Basically I went in testing all components that would register on my multimeter(capacitors can't be read. Anyone know of a good meter for small value caps and resistors?)replacing what seemed odd. I was able to compare with similar parts on the amplifier circuit. Others I just assumed if I got a reading at all it was OK. Those two transistors had no reading whatsoever and one was actually cracked! Talk about clues.
So my search continues for the source of all that noise, but I am reasonably certain I have located the noise suppressing caps. They are in line after the speed control just before going to the motor itself. Looks like a cap and resistor for each pole of the motor. At first I thought I might have found the problem when I discovered that the other side of this cap/resistor pair was not grounded, but when I did ground it, nothing changed. Later this week I'm going to get replacements and hopefully that will do the trick. I am also going to shore up all the grounding to the motor as Martin has suggested.
I have to say, I'm having such fun poking around and learning as I go. One of the joys of this hobby for me is the tinkering with both film and the equipment to run them. I'm sure many will agree with that sentiment!
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