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Author Topic: Repairing a Sankyo Stereo 800 - The Journey
Janice Glesser
Film Goddess

Posts: 3301
From: Sunnyvale, CA USA
Registered: Sep 2011


 - posted July 06, 2013 12:53 AM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
I got a little lost here...I was not sure where to put the dial on the multimeter...This meter was $4.99 from Harbor Freight...very basic.

Here was my guess...

 -

I pulled both the power selector switch and the power socket out...but the wires all looked good.

The power selector switch was already set to 117V,not 110V.

Ground to Chassis Test

 -

Brown Wire to Power Selector Dial Test

 -

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

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

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Pete Richards
Master Film Handler

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From: Australia
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 - posted July 06, 2013 02:39 AM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
Excellent guess!
Those two wires are funtional then.
You may want to unscrew the sockets as per my pictures and check out the blue wire.

I know it sounds silly, but have you double checked that the power cord and wall socket are still working correctly? I spent ages trying to fix something once only to eventually find that I had killed the wall socket!

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Maurice Leakey
Film God

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From: Bristol. United Kingdom
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 - posted July 06, 2013 03:51 AM      Profile for Maurice Leakey   Email Maurice Leakey   Send New Private Message       Edit/Delete Post 
Janice

I look forward to your daily reports, I do hope you get there in the end.

I once bought a projector on eBay which looked just perfect out of its box but the troubles started when I tried to use it. My service engineer discovered that just about every soldered joint was dry, and parts of the PCB on the amplifier had soldered sections where the board connections had been damaged.

It is, of course, difficult to spot a dry joint. Possibly it could mean re-soldering every joint.

Good luck to you.

--------------------
Maurice

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Pete Richards
Master Film Handler

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From: Australia
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 - posted July 06, 2013 04:59 AM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
I don't think a dry joint is the issue here. We had a partially functional projector that then got shorted out and has become non functional and has a nuked track on the board.

Dry joints are often a problem in old gear though.

I am worried that the transformer windings have burned out and become open, but hopefully there is a hidden fuse in the wiring that has gone pop!

[ July 06, 2013, 01:28 PM: Message edited by: Pete Richards ]

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Janice Glesser
Film Goddess

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From: Sunnyvale, CA USA
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 - posted July 06, 2013 03:40 PM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
Pete...I PM'd you about the schematics

===================

BTW..The lamp IS still working. I think I only blew something in the sound system.

Does this verify that the Transformer is OK?

 -

Since there is no power getting to the PCB because of the damaged section...does that mean we can't test the rectifiers or capacitors? ... From comments others have made... most indicate problems with those components.

The power cord is fine...I have examined all wires...they look fine too.

[ July 06, 2013, 05:32 PM: Message edited by: Janice Glesser ]

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

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

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Pete Richards
Master Film Handler

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 - posted July 06, 2013 08:42 PM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
That is good news then!

I find that a bit baffling though... Can you check, if you switch the lamp between High and Low output, does it change?
If it does, can you check the voltage on the lamp wires again, the ones next to the H L switch.

It means that the transformer is at least partially working, as the lamp gets its power from there.
There are multiple outputs from the transformer though, and one may have blown. But it does mean the blue wire is okay, and the 240v and power selection wiring is working to get power to the transformer, which is good news.

Can you double check those first two test points I mentioned to see if they are getting the 15v power now?

BTW, the dropbox link didn't work for me. Could you send them via wetransfer.com to me? My email is peter at mudgee dot net thanks!

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Pasquale DAlessio
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From: Bristol,RI, USA
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 - posted July 06, 2013 09:33 PM      Profile for Pasquale DAlessio   Email Pasquale DAlessio   Send New Private Message       Edit/Delete Post 
Your seeing it unfold here as it happens folks! [Eek!] Live as it happenes with on the scene reports. [Big Grin] Three pages of up to the minute news on the dead Sankyo 800. [Frown] Will Janice be able to save it? [Confused] Will she get help in time? [Confused] Stay tuned for the exciting conclusion of "The Sankyo 800" right here on "The Forum" [Roll Eyes]

And now a brief word from our sponsor [Cool]

Hello ! Are you smoking more and enjoying it less? Are you coughing all the time? Then this advice is for you. FREAKING QUIT !!!!

This was a public service announcement. [Smile]

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Pete Richards
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 - posted July 06, 2013 10:32 PM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
I know people write 'LOL' all the time, but for once I actually did!

Thanks for the Schematics, I'm going over them now, it will make treating the patient much easier.

I am surprised the lamp is now working, if you could recheck all the voltage points we have mentioned in the whole thread again *while the light is on* that would be great.

Except for the power socket/voltage selector post.

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Janice Glesser
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 - posted July 07, 2013 01:26 AM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
 -

....and now back to our regular scheduled program. [Cool]

================

I'll report back on the test with the light ON.

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

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

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Pasquale DAlessio
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 - posted July 07, 2013 09:01 AM      Profile for Pasquale DAlessio   Email Pasquale DAlessio   Send New Private Message       Edit/Delete Post 
Hotel 99

We'll leave the light on for ya! [Wink]

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Janice Glesser
Film Goddess

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From: Sunnyvale, CA USA
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 - posted July 07, 2013 06:06 PM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
Thanks Pat...I wish I had an exciting development to report...but it looks like the light is the only thing that is on [Roll Eyes]

Pete...No change in any of the results on testing again with the LAMP ON. The "H" switch does control the light brightness...but voltage still measures .0 with the multimeter on both the yellow and red wires. I'm not sure how that is possible...it has to be getting power. [Confused] ... AND... Why are there no fuses? I admit to being a bit confused at this point. Do the schematics show any reason for this?

If I were to take this to an electrician...What would I tell them based on the testing we have done already.? Other than the problem on the PCB board...What have we determined?

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

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

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Pete Richards
Master Film Handler

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 - posted July 08, 2013 04:32 AM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
The schematics clearly show that there should be fuses, they may have been removed by another owner, or your projector is just a different revision.

Just to double check, for the wires on the lamp switch is your meter set to AC or DC?

Before taking it to anyone it would be best for us to check the bridge rectifiers and see if they are blown first.

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Janice Glesser
Film Goddess

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From: Sunnyvale, CA USA
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 - posted July 08, 2013 04:45 PM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
If you check the photos from June 5th you'll see the meter is set to ACV 200. It was the same on the second tests too. When I touch the black probe to the chassis there is a little jump...number goes .3 -.0 very quickly. It could be that the voltage is just very low going to the "H" switch. The light does change brightness when moving the switch from H to L... however it doesn't appear to be a significant change in brightness...but then I don't have anything to compare it to. This may be normal.

I think the multimeter is operating ok since I'm able to measure battery voltages correctly.

How do you recommend I test the Bridge Rectifier? I can use the little hooks this time...but don't know where to place them and what do I set the meter to. Also, just in case you need me to check the big capacitor next to the Bridge Rectifier... One end is difficult to reach...I would need a right angle probe to test that end. For that matter...I'm not sure if my multimeter measures capacitors [Confused]

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

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

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Pete Richards
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 - posted July 08, 2013 09:34 PM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
Test the wires near the switch with it set to DC and let me know the results.
Sorry I am not at home at the moment to follow along, I've been in and out of hospital with my daughter. Hopefully will be home soon and can document how to check the rectifier and other components.

Do you have the possibilty of setting up Skype with a camera so I could see what you were doing real time, so to speak?

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Janice Glesser
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 - posted July 08, 2013 11:26 PM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
Hey Pete, seems you have a lot on your plate right now...this can wait...by all means take care of your daughter. I hope she is ok.

I'll do the switch test on DC and take pictures.

I'll have to think about webcaming the testing...I just don't have a good way to do that right now. I use Google Talk and Google Hangout for web conferencing.

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

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

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Mike Peckham
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From: West Sussex, UK.
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 - posted July 09, 2013 09:39 AM      Profile for Mike Peckham   Email Mike Peckham   Send New Private Message       Edit/Delete Post 
John Capazzo said:

quote:
This isn't the first time I've heard of motors failing on Sankyo machines. It's VERY rare for Elmo motors to fail, but Sankyo machines are almost common.

Which is odd, because Elmo and Sankyo sourced their motors, sound heads and numerous other parts from the same suppliers - in fact the Sankyo 800 motor and the GS 1200 main motor are the same part.

Janice, this thread is a great read, I'm willing that machine to come back to life and looking forward to each new installment. I understand that it's necessary for progress to slow a little whilst Pete takes care of his daughter, but I'm looking forward to seeing you get to the route of the problem.

Good Luck! [Smile]

Mike [Cool]

--------------------
Auntie Em must have stopped wondering where I am by now...

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Janice Glesser
Film Goddess

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 - posted July 09, 2013 01:53 PM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
Thanks for the vote of confidence Mike. I don't think the motor is at fault either...but tracking down the real culprit is not easy.

I'm happy that you and some others find this thread entertaining and hopefully informative...AND if there are more electricians out there ...don't be shy... please join in....all comments welcome [Smile]

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

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

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Steve Klare
Film Guy

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 - posted July 09, 2013 02:14 PM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
No!

This machine must work again!

Epics always end heroically!

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

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Paul Adsett
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 - posted July 09, 2013 02:43 PM      Profile for Paul Adsett     Send New Private Message       Edit/Delete Post 
Good to see Mike posting again. [Smile]

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,

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Pete Richards
Master Film Handler

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From: Australia
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 - posted July 09, 2013 07:15 PM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
We will get it going!!

I wish I was on the same continent and could help out more.

We can test the motor easily enough, I will be back on deck later this week. In the meantime, give those DC readings a go, it will help a lot with what to do next.

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Janice Glesser
Film Goddess

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From: Sunnyvale, CA USA
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 - posted July 10, 2013 04:10 AM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
One of the metal probes fell off my multimeter ... so I got a little practice soldering it back on....I think I need to get a little bit better meter. I don't think this one will hold up to too much abuse [Frown]

Here is a video of the voltage tests on the Hi/Low Switch wires. The power cord is plugged in and the selector switch set to lamp on. The readings bounced around so much a single photo wouldn't work. I don't even know if I had the meter set correctly...but it was the only way to get any reading.

http://www.youtube.com/watch?v=Td_z42gaHho

 -

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

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

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frank arnstein
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 - posted July 10, 2013 10:03 AM      Profile for frank arnstein   Author's Homepage   Email frank arnstein   Send New Private Message       Edit/Delete Post 
Hi Janice,

While waiting for fresh ideas, here's something for you to check out and also a possible fuse location for the amp.

On your 3rd picture the speed board is visible on the left side and it has a big black heat sink mounted on it. Remove the 2 screws that hold the speed board in place and then slide the board out towards the rear. Remove any connecting sockets that may hinder the board from sliding out far enough to turn it over.

Then you can look down at the big amplifier board located underneath. There should be a glass fuse located some-where on that board and it may well be blown.

Next, carefully turn the speed board over to examine the 3 solder joints found underneath, connecting a small black box that is screwed to the heat sink. It has 3 terminals soldered to the speed board any or all of them may have melted, giving an open circuit to the motor. This weird little box gets mighty hot and has to get rid of that heat fast. If not, it just builds up until it melts the solder on its own terminals and then the motor may stop.
Refit and resolder into place any of these 3 that may have melted and then try testing it again after carefully refitting the speed board back in place.

Let us know what you find and anything fresh. Many of us are following this saga with great interest and hope it concludes favorably soon.
[Wink] [Smile]

dogtor frankarnstein

--------------------
At Projector Heaven the Focus is always on Detail.

____
[o:/o]<|=- dogtor@projectorheaven.com.au
//``\\
-----------------------------------------------

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Pete Richards
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 - posted July 10, 2013 06:30 PM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
Thanks for the video, it makes things so much more clear. I will make one up this weekend of testing all the main components for you and show the meter settings etc. I think it is the best way after seeing your vid.

Just a quick note re the meter. It is fine for the task, I'd just buy a better quality set of test leads.

Now with that meter, (sorry if you already know all this) the settings for voltage work like this.
Your meter needs to be set to the maximum voltage you are likely to expect. So if you were testing the house mains power (110v AC in the USA), you would set it to ACV 200, and then it will give the corect reading. If I was to test the mains in Australia (240v) I would have to set that meter to ACV 750, as our voltage is higher than the 200V setting on that meter, so we need to move up to the 750V setting. Now you could of couse test the 110v on the 750V setting, but it wouldn't be quite as accurate.

For the DC Voltage, your meter has settings for 1000Volts DC, 200V DC, 20V DC, 2000millivolts DC (same as 2V DC), and 200mv DC (same as one fifth of 1V).

So if you were testing a 9V battery, you would set the meter to 20V DC. If you were testing a little circuit with tiny amounts of voltage (say 80 millivolts) yoy would set the meter to the 200mv setting and so on.

In this case, the readings you are getting are only a few millivolts, and are swinging around wildly, so something is wrong somewhere.
If you could check your meter is working properly, by setting it to 20V DC and placing the probes on a normal 1.5V battery or a 9V battery and check that you get a reading of 1.5V or 9V on the meter. (ie any standard batteries you have around the house).
If the meter is reading correctly, then I will make up a video for you and we can test all the various bits and track down the problem.

We will be testing some individual componets, like resistors and rectifiers etc. and checking voltage levels across the board in AC and DC. I have a meter with a similar layout to yours, so I will use it.

[ July 10, 2013, 10:18 PM: Message edited by: Pete Richards ]

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Janice Glesser
Film Goddess

Posts: 3301
From: Sunnyvale, CA USA
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 - posted July 10, 2013 06:37 PM      Profile for Janice Glesser   Email Janice Glesser   Send New Private Message       Edit/Delete Post 
Thank you Frank for jumping in here. This helped alot! Removing the speed board revealed another burned out section of the PCB. I still can't find a fuse in this machine. Why would anyone remove them? I also wasn't clear on the "black box" either...but everything else appears ok on the board.

As per Franks instructions: I removed the two screws and then the 5 connecting sockets. I had already removed the 6th socket that attaches to the speakers. (Note: I numbered all the sockets so I could put all the wires back in their right places [Smile] )

 -

I then pulled the speed board out.

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...and flipped it over.

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Close-up of bad section on PCB. The Bridge Rectifier is connected to this section.

 -

Examined the sound board...but still can't see a fuse anywhere.

 -

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

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

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Pete Richards
Master Film Handler

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From: Australia
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 - posted July 10, 2013 07:28 PM      Profile for Pete Richards   Email Pete Richards   Send New Private Message       Edit/Delete Post 
Now that you have the sound board out, we may as well test some components. Do you have some suitable guage wire to repair the broken tracks with? Unfortunately that track has lifted and appears to also to be shorting the other solder junction.
These tracks most likely vapourised when you shorted the voltage rectifier.

I'll be home in a few hours and take some pictures of how to test the various parts now that the board is out.

Oh and I just realised, it looks like the lamp is on even when the projector is in the 'STOP' position. Is that the case?

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