8mm Forum: Repairing a Sankyo Stereo 800

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Topic: Repairing a Sankyo Stereo 800 - The Journey

Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted November 09, 2016 02:58 PM

Mark...I checked again at what I ordered...it's a Panasonic GE capacitor, not a Nichinon. I've been ordering so many components lately it's hard to keep track. [Eek!]

I guess I'll just wait.

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Mark Creighton
Junior
Posts: 21
From: Schodack, NY, USA
Registered: Mar 2016

posted November 09, 2016 05:48 PM

Janice,

The Panasonic should be good.

Mark

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted November 09, 2016 07:04 PM

Usually these components are rated for tens of thousands of hours of operation at temperatures most of the way to boiling!

So any decent commercial grade capacitor should do you just fine.

BTW: I'm a United Chemicon man myself! (For some reason the people I work for have always preferred them.)

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All I ask is a wide screen and a projector to light her by...

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted November 09, 2016 07:14 PM

No worries Janice, you're welcome! [Big Grin]

Go for the best rated,the difference in price is minimal...
105 degree rated and 5% close tolerance. [Wink]

Reputable manufacturer, but the above is the more important.

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"C'mon Baggy..Get with the beat"

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted November 09, 2016 09:00 PM

-but even if all you can find is 85C, don't lose any sleep over it. Unless the house is on fire that cap will never reach 185F.

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All I ask is a wide screen and a projector to light her by...

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted November 10, 2016 04:13 AM

Just built to higher standard with greater head room, that's all Steve.

Factor of safety and all that.
We use an 8 tonne overhead crane in work, but it never sees more than 2t

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"C'mon Baggy..Get with the beat"

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted November 10, 2016 06:09 AM

-not necessarily.

Very often you see the 85C part rated at 2X hours of Mean Time Between Failures and the 105C part rated only X hours. It's possible they are the exact same part with a different label.

My point is if Janice has an 85C part it's more than good enough. It's what the machine was probably built with in the first place since it's a consumer product.

The life of a capacitor in a super 8 projector is actually pretty plush: two hours a week year round is a lot and that's 100 hours a year. If you can only find a thousand hour part you are already good for 10 years. If that thousand hours is really only at like 40C it's probably more than 20 years.

20 years of this kind of service, everything else in the machine will be a pile of rubble! If nothing else the shelf life issue eventually gets them all regardless of the rated hours.

The systems I work on are intended to be up 24/7/365, so we would definitely go with the higher rated part: maybe save us having to get out of bed and go in at 3AM some winter night someday. (Comes with the job...)

-105C part if you can, 85C part: no anxiety!

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All I ask is a wide screen and a projector to light her by...

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted November 10, 2016 06:16 AM

Yes fair points there, as you say all of these things ARE considered consumable items so for the amount of use, many give to these things, I am sure you're right.

I have to say though, I use my main projectors far more than two hours per week, so for the difference in price, I'd always plummet to fit the best available for my own needs.
There is after all, very little differences in prices typically.

As you say though, not everyone is using these things now to the extent I personally do, and no doubt, you do yourself Steve.

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"C'mon Baggy..Get with the beat"

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Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted November 10, 2016 06:29 AM

I'd say an hour a week per machine would be a lot for me personally: I might only show one reel on a work night and I almost always run with two machines, so when it comes to even two 200 footers I do a changeover and the time is divided. I also rotate machines in and out of service and the guys on vacation can sit for weeks.

I'm guessing when you change a lamp, you can still remember the last time you changed it.

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All I ask is a wide screen and a projector to light her by...

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Andrew Woodcock
Film God

Posts: 7477
From: Manchester Uk
Registered: Aug 2012

posted November 10, 2016 07:07 AM

Yes Steve. Every time. With the exception of my ST 1200 nowadays and my 938 gets very little run time per annum now.

I usually run a couple of features (two or three) and around 5 shorts per week.
I am a shift worker, so I do get plenty of time to view the films I have when I'm off and the wife is in work.

Plenty of time, yet still nowhere near enough for what is needed! [Big Grin]

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"C'mon Baggy..Get with the beat"

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted November 10, 2016 04:07 PM

Hi Andrew...in regards to the relays, thanks for the info. At this point I don't know if they are good or bad. I couldn't find these exact ice cube relays...but have located an equivalent if I need to replace.

1)I'll start replacing the big capacitor and adding the 6 amp fuse. Then put everything back together and test it.
2)If still no sound... then I'm going to replace the power amplifier transistor on the small speed board.

3) If still no sound...replace the two 470uf capacitors near the IC's.
4) If still no sound...test and possibly replace relays.
5) If still no sound...I don't want to go there [Roll Eyes]

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted May 05, 2017 11:45 AM

UPDATE....No, I still haven't resolved the sound issue, but I haven't been working on the projector recently. If you venture back in this thread to my previous post you will see a list of my next steps. One of the to-do's in my list was to check the relays. I ran across a video on YouTube where this guy showed a nice little trick to test relays with a 9 volt battery.

https://youtu.be/uM8BO3pItec

I gave it a try and sure enough both relays were working. So I guess I can check relays off my list [Smile]

ALSO...I did complete #1 on the list. I replaced the capacitor and added a fuse holder and fuse. Still no sound [Frown]

NEXT: #2 - Replace power transistor

[ May 05, 2017, 05:03 PM: Message edited by: Janice Glesser ]

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted October 02, 2017 08:12 PM

Replaced the transistor on the power board today. Unfortunately this component was not the problem and still complete silence.

This is what I know:
1) Power is getting to the motor and it runs great.
2) Power is getting to the lamp

I do not know if power is getting to the sound board or amp.
How can I test this?

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Graham Ritchie
Film God

Posts: 4001
From: New Zealand
Registered: Feb 2006

posted October 02, 2017 09:42 PM

Janice I am certainly not an expert in amps...but my guess would be if you can hear hum from the speaker when cranking the volume to full running the motor as well then the amp is working...no hum.. no amp [Smile]

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted October 03, 2017 12:37 AM

Well Graham then I know one more thing...

There's no hum...so no amp [Frown]

It's sad to see such a nice stereo projector so crippled. I just don't know enough to intelligently troubleshoot where the disconnect is located. Even having all the circuit designs hasn't been much help.

I know something blew when I touched a metal bar by mistake. Poof!... and it went silent.

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Graham Ritchie
Film God

Posts: 4001
From: New Zealand
Registered: Feb 2006

posted October 03, 2017 02:07 AM

Hopefully someone will come to your rescue Janice.

Just thinking, is the pre-amp still ok? If the main amp is gone and the pre-amp is ok then by pass it to a aux out, then run the leads to a external amp..or get one of those amp kits you can buy and build a new one. Another thought an old cassette tape deck scrap it and take the pre-amp out of it and wire it to projector sound head..to a aux out...external amp [Roll Eyes]

I think you will get there in the end, it might even be nothing more than a blown transistor..but I think you need to take it to an electrical repair to fix it.

Anyway food for thought...

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted October 07, 2017 11:23 AM

Just when I think the plot points in this novel (actually this is a documentary) have gone dry... a small spark of hope emerges [Smile]

Graham... you got me brainstorming again that this might be as simple as a blown transistor. I had been spending hours and days trying to learn about amplifiers and the components. However, I decided last night to go back and re-read this thread. I don't know how I missed it...but Pete Richards had suggested replacing the green Toshiba 1B2Z1 rectifier. In the same area as that rectifier I had already replaced a large capacitor and added a fuse. I never followed up on identifying and replacing that rectifier. I guess at the time I didn't know what that green thing was (: . Anyway... I also located an old thread from 2006 http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=001730
Here Jan Bister had almost the identical problems with his Sankyo 800. He mentions replacing that same rectifier and it restored the sound to his projector.

After this epiphany at 1 a.m. in the morning... I found the part on Ebay. It should arrive by next Friday.

Crossing fingers....Stay tuned for this next chapter [Smile]

[ October 07, 2017, 08:55 PM: Message edited by: Janice Glesser ]

--------------------
Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted October 17, 2017 06:16 PM

I replaced the Green Rectifier yesterday...but unfortunately "no joy." I've now ordered a replacement for the black rectifier that sits right next to the green one. It measures correctly with the ohm meter...but Pete Richards says it may not work under a load.

Granted I'm disappointed...but I did learn something about a rectifier stack and it's polarity. Unlike a bridge rectifier that has 4 terminals...a rectifier stack only has 3 with the center terminal being common... positive or negative. On the Sankyo 800...the green rectifier has a positive common...where the black one has a negative common.

The new black rectifier is coming from the UK and will take a couple of weeks. I'll report back then.

--------------------
Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted November 05, 2017 07:03 PM

Got the replacement black rectifier installed... but still complete silence [Frown]

Graham...How do I test to see if the pre-amp is working?

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Thomas Knappstein
Expert Film Handler

Posts: 124
From: Erwitte, Germany
Registered: Oct 2017

posted November 07, 2017 11:44 AM

I dont have this Sankyo 800 machine but the same Rectifiers are in my Elmo GS 1200. The green one and the black one together make a normal Bridge Rectifier because there are two Diodes in the Green one and two diodes in the black one.
If you have changed both of them and canged the big Capacietor there must be a Voltage about 15-20Volts measuring on the Capacitor. If it is not check the AC Voltage on the Transformer. I dont think that the Preamp is defektive. I think if it´s not the Power Supply it could be the End Transistors ore Hybrid Part. Because If the Preamp is defektive and enything else is ok than you must here a Hum in the Speakers but no Sound of the Film. And you say that there is no Hum so it could be an Idea.

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted November 07, 2017 07:21 PM

Hi Thomas...I greatly appreciate your thoughts. I haven't checked the voltages since I got the motor running on this machine. I'm always hesitant to test with the AC plugged in...that's how I blew it in the first place. [Eek!]

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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Thomas Knappstein
Expert Film Handler

Posts: 124
From: Erwitte, Germany
Registered: Oct 2017

posted November 07, 2017 10:24 PM

I hope you will fix this Problem and it will run once a Day.

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted January 12, 2019 02:22 PM

It's been a little over a year since I updated this thread and I'm happy to announce that I finally have a fully working Sankyo Stereo 800. Here is how it went:

I was able to buy a second "non-working" Sankyo 800 for a very low price. The sound was working on this projector, but the motor wasn't running.

I pulled out the power board and discovered that like the first projector...the bridge rectifier was cracked...

...and the PCB trace was burnt.

In hopes that with the repairs I had already done to the power board on the first projector would be suffient... I decided to switch out the boards.

When possible I try and number the connectors and the wires so I don't have to guess later on when reconnecting.

SUCCESS!!!! The projector motor started right up...the arm spindles were turning and the sound lights all turned on.

I'm happy to have a working projector, but feel bad I couldn't get the sound working on the original machine.

Thanks everyone who contributed to this thread. It has been a wonderful learning experience and I hope others can benefit from the information. [Smile]

[ January 12, 2019, 06:15 PM: Message edited by: Janice Glesser ]

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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James N. Savage 3
Phenomenal Film Handler

Posts: 1375
From: Washington, DC
Registered: Jul 2003

posted January 12, 2019 07:15 PM

Thanks so much for the update Janice! So glad to get a happy ending on your Sankyo project. Hope you will enjoy your machine for many years as I have too.

James

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Janice Glesser
Film Goddess

Posts: 3468
From: Sunnyvale, CA USA
Registered: Sep 2011

posted January 14, 2019 09:52 AM

I'm glad to finally wrap up this project James and thanks for your interest. Sankyo has made some great projectors and I've owned several models. The Sankyo Stereo 800 is the top-of-the-line and a pleasure to run.

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Janice

"I'm having a very good day!"
Richard Dreyfuss - Let It Ride (1989).

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