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Author Topic: Snap, crackle, pop!
Patrick McGrath
Film Handler

Posts: 97
From: Huntington Beach, CA
Registered: Jul 2008


 - posted September 16, 2008 09:18 PM      Profile for Patrick McGrath   Email Patrick McGrath   Send New Private Message       Edit/Delete Post 
Hello once again...
Last time I logged in I was very proud of myself for getting this yashica p810 up and running but now I am attempting to repair the amplifier section.
I must admit I am a bit out of my league but I am a quick study so the unit is apart and on the bench again.
I wonder if anyone has any input on this particular symptom?
When I turn up the volume I get a lot of crackling and popping sounds with no film running through it at all. This occurs in both mag and optical settings.
A good friend of mine suspected the electrolytic caps, so I replaced all of them to no avail. Too bad, it was nice job at that.
So now I'm wondering what to go after next? The transistors? I have found a source, but I don't want to buy 40 dollars worth of transistors if I'm barking up the wrong tree.
Anybody?

If neccessary I will post a pic of the circuit board.

[ September 16, 2008, 10:36 PM: Message edited by: Patrick McGrath ]

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Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003


 - posted September 16, 2008 09:52 PM      Profile for Paul Adsett     Send New Private Message       Edit/Delete Post 
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.

--------------------
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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Jose Artiles
Master Film Handler

Posts: 357
From: Spain
Registered: Oct 2005


 - posted September 17, 2008 08:20 AM      Profile for Jose Artiles   Email Jose Artiles   Send New Private Message       Edit/Delete Post 
Hi Patrick,maybe you must clean all the switches because dirt is the guilty a lot of times of the sound pops and crackings,use a swicht cleaner,you can buy it at electronic stores.

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As Steven Spielberg says....
Nothing beats old school projection. Digital is just an imitation.

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Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008


 - posted September 17, 2008 09:42 AM      Profile for Martin Jones   Email Martin Jones   Send New Private Message       Edit/Delete Post 
Patrick,
Quoting you...."When I turn up the volume I get a lot of crackling and popping sounds with no film running through it at all. This occurs in both mag and optical settings."
Do you mean that you get those noises WHILE you are moving the volume control, or do they occur ALL THE TIME the volume is turned up high?
If the former, the volume control needs cleaning, which can be done by squirting switch cleaner into it through any available orifice, and then working the control backwards and forwards. That may also be the cure for the other option if the control is realy dirty at the high end. I always use "Electrolube" which is difficult to find these days; I still have a store from my working days (not available for sale, chaps!!) or Servisol Switch Cleaner. Another good cleaner is Singer Sewing Machine Oil; 3-in-one is a little too thick and messy.
Another thought.... make sure the kids have not spilt Rice Crispies in it!
Martin.

--------------------
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


 - posted September 17, 2008 10:26 AM      Profile for Patrick McGrath   Email Patrick McGrath   Send New Private Message       Edit/Delete Post 
Unfortunately, the crackling happens all the time. I wish it were just when I move the volume. I'm familiar with that.
Thanks anyway...

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Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008


 - posted September 17, 2008 10:59 AM      Profile for Martin Jones   Email Martin Jones   Send New Private Message       Edit/Delete Post 
Patrick,
Further questions.. are they present at all at lower volumes or do they start to occur only when a certain level is reached? Do they then get louder as you turn the volume higher still?
Martin

--------------------
Retired TV Service Engineer
Ongoing interest in Telecine....

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Osi Osgood
Film God

Posts: 10204
From: #399R K.O.A. Mountian Home, ID. 83647
Registered: Jul 2005


 - posted September 17, 2008 12:42 PM      Profile for Osi Osgood   Author's Homepage   Email Osi Osgood   Send New Private Message       Edit/Delete Post 
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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Patrick McGrath
Film Handler

Posts: 97
From: Huntington Beach, CA
Registered: Jul 2008


 - posted September 17, 2008 01:53 PM      Profile for Patrick McGrath   Email Patrick McGrath   Send New Private Message       Edit/Delete Post 
Martin,

Yes the crackling gets progressively louder when I turn up the volume control, but the noise is there even at the lowest levels.
Keep in mind, I am not running any film though the projector when this occurs.(I don't have any sound films yet!)

Osi,

I had some trouble getting the front off but discovered three screws; one behind the vu meter to the right, one just to the left of the vu meter and one under the detachable lens/screen thingy(sorry about that)at the far left of the projector.
Also there is a screw holding the function knob in place which is very difficult to manage but that knob must come off in order to access the interior.
BTW, I haven't forgotten your request for a pic of the rewire I did in order to bypass the speed control. I just haven't had a chance to get out the digital camera and do it! Maybe now is the time seeing how it is dismantled completely.
I would still like to get the speed control working and I thought about just rebuilding it component by component.

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Osi Osgood
Film God

Posts: 10204
From: #399R K.O.A. Mountian Home, ID. 83647
Registered: Jul 2005


 - posted September 17, 2008 04:20 PM      Profile for Osi Osgood   Author's Homepage   Email Osi Osgood   Send New Private Message       Edit/Delete Post 
You've really got me going on wanting to get this Yashica P810 up and running. haven't been able to find those two screws to get off the front lower cover though. I'm looking forward to it!

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"All these moments will be lost in time, just like ... tears, in the rain. "

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Patrick McGrath
Film Handler

Posts: 97
From: Huntington Beach, CA
Registered: Jul 2008


 - posted September 17, 2008 09:32 PM      Profile for Patrick McGrath   Email Patrick McGrath   Send New Private Message       Edit/Delete Post 
Just an update.

A knowledgeable man on the 16mm list named Ken Layton asked the question if the noise stopped when the motor was off, or something to that effect.
Having a three position rotary switch made this a little tricky to test but I went in and disconnected the motor while in the sound on position and the noise went away!
I understand that there may be some capacitors in the circuitry to suppress this interference. Perhaps they have failed.
Now, how do I locate those?
I wish I could find a schematic for this machine but nothing exists on the internet.

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John W. Black
Jedi Master Film Handler

Posts: 536
From: Deptford,N.J.
Registered: Mar 2008


 - posted September 18, 2008 01:29 AM      Profile for John W. Black   Author's Homepage   Email John W. Black   Send New Private Message       Edit/Delete Post 
If it stops when the motor is disconnected,the problem is probably a noise filter.A suggestion,check with repaimen at local music stores,if you find an older amp repairman,at some point in time,most likely he worked on projectors.Also.the best pot cleaner by far is a product called Lube Job.It cleand out pots that others won't.

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Beat em or burn em,they go up pretty quick

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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003


 - posted September 18, 2008 02:34 AM      Profile for John Clancy   Author's Homepage   Email John Clancy   Send New Private Message       Edit/Delete Post 
Does the projector have hifi line outs on it? I have a similar popping problem on a Chinon SS1200 but only through the on board amplifier. Running the line outs to a separate amplifier means the problem does not exist.

--------------------
British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008


 - posted September 18, 2008 02:58 AM      Profile for Martin Jones   Email Martin Jones   Send New Private Message       Edit/Delete Post 
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 ]

--------------------
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


 - posted September 21, 2008 01:29 AM      Profile for Patrick McGrath   Email Patrick McGrath   Send New Private Message       Edit/Delete Post 
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]
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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