8mm Forum: Sankyo Stereo-800 Nasty Hum

This is topic Sankyo Stereo-800 Nasty Hum in forum 8mm Forum at 8mm Forum.

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Posted by Jon Addams (Member # 816) on March 23, 2010, 09:27 PM:

Today I got ready to watch Viva Las Vegas only to find out my Sankyo 800 had a nasty hum, I mean really loud! I have no idea what is causing this, I used this projector on Sunday and everything was perfect.

Okay, now I have a brand new meter, any ideas where I may start looking for the source!

Thank you

Jon

Posted by Steve Klare (Member # 12) on March 23, 2010, 10:03 PM:

Hmmmm....(no pun intended....at least initially!)

Try looking for some seriously large electrolytic capacitors that are the filter network for the sound board power supply and measure the dc voltage across them. Find a spare capacitor of similar value, put it in series with the meter and take the AC voltage measurement at the same point (mind the capacitor polarity). This is a test to see if those capacitors are working, the AC measurement should be a tiny fraction of the DC measurement.

Do you have schematics?

Posted by Jon Addams (Member # 816) on March 23, 2010, 10:34 PM:

I should have the schematics next week Steve, I just ordered the repair manual.

Thanks for the initial tips.

Jon

Posted by Steve Klare (Member # 12) on March 24, 2010, 08:24 AM:

Excellent!

Troubleshooting without a schematic is like driving a car with the windshield painted over.

Posted by Rick Skowronek (Member # 385) on March 25, 2010, 12:08 PM:

May also want to try, with power off, moving the record/play switch back and forth several times as well. This is not to say that it may still not be an electrolytic failure but (typically) they fail somewhat slowly. The fact that a few days earlier it was perfect says that you may just have a dirty switch which happens with these older machines especially when you don't use the switch much.

Just a suggestion.
Rick

Posted by Steve Klare (Member # 12) on March 25, 2010, 12:12 PM:

It's a good thought.

I had the sound fail on my PC recently and after I worked all the switches and jacks associated with audio it returned to normal.

-the things you learn messing around with Super-8!

Posted by Rick Skowronek (Member # 385) on March 29, 2010, 05:48 PM:

Jon,

Just wondered if you tried this or even had a chance to. Helps all of us to know what may or may not work with our projector issues.

Thanks,

Posted by Jon Addams (Member # 816) on March 29, 2010, 11:11 PM:

Hello Rick,

I haven't try that yet because I am out-of-town until Wednesday but I will give it a go as soon as I get back.

And yes, IMHO, it's always important to post back with the solution when an issue has been resolved.

Thanks

Jon

Posted by Jon Addams (Member # 816) on April 03, 2010, 09:49 PM:

I tried all the tricks you guys mentioned without luck. I will wait for the repair manual, bought it on eBay, but it hasn't shown up yet.

I will post back when and if I solve the problem.

Jon

Posted by Rick Skowronek (Member # 385) on April 05, 2010, 11:00 AM:

That's too bad Jon. Now the real fun begins.
Rick

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