Posts: 671
From: Villeneuve St Georges, France
Registered: Dec 2015
posted June 26, 2017 11:39 AM
Hi Peter,
I understand you replace components (Rectifier(s) Bridge(s) & Capacitors) but one of them failed again.
Is the last picture showing new components ? If Yes, one bridge looks out of order.
Could you tell me parameters for these Bridges (means Voltage rate and Current ) If you have no reference for Bridges, you can get an idea like this : Current 3A = 1 square mm for component terminal/wire section (Approx)
Is there any fuse between Transformer and rectifiers ? Try to disconnect wires (for Amplifier or Motors) which are normally localised between Rectifying stage (Bridge + Capacitors). "Power on" Projector and check output DC Voltage after from output Bridge. If All is OK (means No fume and No Over heating observed) there is a high probability for a Short Circuit Just After Rectifying Stage.
Posts: 40
From: San Diego, CA, USA
Registered: Jun 2017
posted June 26, 2017 03:29 PM
I applaud the selfless generosity of the members' time and advice here. Perhaps I shall tackle the Sankyo but now that I have a working B & H, in a less fervent manner.
Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003
posted June 26, 2017 04:15 PM
Sometimes the best thing to do is put it away and do something else for a while.
If you go back to it, how I would deal with this is snip out the burnt rectifier, hang an ohmmeter on the (+) and (-) terminals, (hopefully) observe the short circuit and then start disconnecting and reconnecting things from the motor, through the switches and then back to the board watching to see when the short disappears.
-at least then you know what general neighborhood your troublemaker is hiding in.
Plus: troubleshooting with no power, and no smoke!
-------------------- All I ask is a wide screen and a projector to light her by...