From: New York, NY, USA
Registered: Apr 2007
posted 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!
From: Long Island, NY, USA
Registered: Jun 2003
posted 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?
-------------------- All I ask is a wide screen and a projector to light her by...
From: Marietta Georgia USA
Registered: May 2005
posted 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.