Question about Marantz PM-68 Amplifier
Your no doubt finding the speaker safety/turn on surge protect relay NOT engaging a few seconds after turning it on-right? Check the output transistors. These are the big green and black ones screwed to the heatsink. You gain access to them by taking off the bottom cover. There's 4 per channel--2 green and 2 black. You'll probably find one or more of them shorted. If you find replacements, put them in exactly as the originals with new thermal grease/heatsink compound. Unsolder and lift the center pin (collector) on each of the four transistors of the effected channel. Power it up and check across the outside pins of each device for proper bias-about a half a volt or so on each one. If the voltage is much higher, or not there you've got other problems that will require more diagnostic/troubleshooting. Do all the lights on the front panel work-or just the tape monitor indicators? If just the tape monitors light up, check resistors RN83 and RN84 on main board under the speaker connector board-remove the speaker connector board to get at them. These are bad on mine and I've yet to replace them. I believe these to be 920 ohm 1% precision resistors....
Posted on May 26, 2008
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Aug 08, 2014 | Marantz Audio Players & Recorders
Jan 14, 2011 | Cambridge Audio Azur 340A 2-Channel...
May 20, 2010 | Audio Players & Recorders
Jan 21, 2009 | Marantz SR6001
Nov 10, 2008 | Marantz SR-7200 Receiver
May 17, 2008 | Audio Players & Recorders
Mar 29, 2012 | Marantz PM-68 Amplifier
825 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: