Marantz Dolby 6.1 right channel fritzed--HELP!

Curious George · 4th June 2004, 03:09 AM

My mother recently blew the right channel of her 6.1 Marantz home theater receiver last month and I have dismantled it and am ready for diagnosis and repair. I will post pictures in my next post. I am wondering if anyone can tell me where on the mainborad I should start my diagnosis. Experience tells me to start with the transistors by measuring for any inconsistencies and then to do the same with the main capacitors (huge 1000 mfd caps). She blew the right channel by letting the + and - wires touch at high volume and now all that comes through the speaker is a faint hint of sound (almost like playing a blown speaker). I would be every so grateful if someone could offer me any advice on the matter. I have a multimeter that I am somewhat familiar with but could use a little help as is apparent. Thanks in advance.

thomas997 · 5th June 2004, 07:45 AM

Is there still a warranty left on the thing?

But wait, that would not be the DIY thing to do would it

SoundQuest · 5th June 2004, 10:42 PM

Nope, warranty expired last year.

SoundQuest · 6th June 2004, 07:19 AM

Here is a bird's eye of the main board, I have circled the sections I would focus in on. Anyone have any direction for me to go on this? I will post another picture of the transistors on one of the channels. I want to test the two huge capacitors to make sure they are both good. How do I test capacitance?

SoundQuest · 6th June 2004, 07:21 AM

Here is the picture

SoundQuest · 6th June 2004, 07:26 AM

Here is the view of some transistors on one of the channels. Whenever I have had blown amps it has always been the transistors. Anyhow, how do I test them? Can they be tested on the board?

richie00boy · 6th June 2004, 11:11 AM

I think you are looking in the wrong places. If it's a 6 channel amp there should be 3 output module/chips at the very least (assuming 2 channels per chip). 6 pairs of transistors if modules/chips are not used. Where is the main heatsink? And what is attached to it?

IMO it's pointless looking at the PSU caps - if there was a problem with them it would affect all channels.

SoundQuest · 6th June 2004, 04:56 PM

I think you are probably right. As you can see, I have removed all of the other boards from this mainboard so I could have access. Which board should I be looking at? I will post another picture after this one of the base unit with the main power supply.

SoundQuest · 6th June 2004, 05:17 PM

I believe this is what you may be talking about. There are six sections respective of the six channels and a huge heatsink for all six channels (as per your description). How can I tell which section is the right channel? Which components should I test when I find the right channel (resistors, diodes, caps, etc)? I don't know if this helps in diagnosing but sound still comes through the right channel it's just that it is muted almost to nothing and sporadic on the sound it lets through.

richie00boy · 7th June 2004, 05:43 PM

Can you trace from the output terminals for the blown channel back to where it connects to that board mounted on the main heatsink?

I suspect just-functioning output transistors. You can diode test them in situ, but I wouldn't bother as they will probably read OK. If you really want to check them, measure all the other ones as well and compare readings. You may have a tough job hunting down exact replacements... They will probably be 2SCxxxx and/or 2SAxxxx devices.

4th June 2004, 03:09 AM	#1
Curious George diyAudio Member Join Date: Mar 2004 Location: Seattle	Marantz Dolby 6.1 right channel fritzed--HELP! My mother recently blew the right channel of her 6.1 Marantz home theater receiver last month and I have dismantled it and am ready for diagnosis and repair. I will post pictures in my next post. I am wondering if anyone can tell me where on the mainborad I should start my diagnosis. Experience tells me to start with the transistors by measuring for any inconsistencies and then to do the same with the main capacitors (huge 1000 mfd caps). She blew the right channel by letting the + and - wires touch at high volume and now all that comes through the speaker is a faint hint of sound (almost like playing a blown speaker). I would be every so grateful if someone could offer me any advice on the matter. I have a multimeter that I am somewhat familiar with but could use a little help as is apparent. Thanks in advance.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
marantz hum on one channel	ian21	Solid State	0	14th June 2008 10:54 AM
Marantz PM44SE - Dead(ish) right channel	nig123	Solid State	7	6th June 2007 06:29 AM
Marantz PM-66SE Blown Channel	Chudley	Solid State	2	8th May 2007 07:28 PM
Marantz CD-73 Low output on one channel	humphrey_plugg	Digital Source	0	22nd May 2006 03:21 PM
Marantz Cd63 - shorted channel?	jlnz	Everything Else	4	26th November 2003 08:06 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

5th June 2004, 07:45 AM	#2
thomas997 diyAudio Member Join Date: Feb 2004 Location: Vancouver	Is there still a warranty left on the thing? But wait, that would not be the DIY thing to do would it

5th June 2004, 10:42 PM	#3
SoundQuest diyAudio Member Join Date: Oct 2002 Location: Seattle	Nope, warranty expired last year.

6th June 2004, 07:19 AM	#4
SoundQuest diyAudio Member Join Date: Oct 2002 Location: Seattle	Here is a bird's eye of the main board, I have circled the sections I would focus in on. Anyone have any direction for me to go on this? I will post another picture of the transistors on one of the channels. I want to test the two huge capacitors to make sure they are both good. How do I test capacitance?

6th June 2004, 11:11 AM	#7
richie00boy Did it Himself diyAudio Member Join Date: Nov 2003 Location: Gloucestershire, England, UK	I think you are looking in the wrong places. If it's a 6 channel amp there should be 3 output module/chips at the very least (assuming 2 channels per chip). 6 pairs of transistors if modules/chips are not used. Where is the main heatsink? And what is attached to it? IMO it's pointless looking at the PSU caps - if there was a problem with them it would affect all channels.

7th June 2004, 05:43 PM	#10
richie00boy Did it Himself diyAudio Member Join Date: Nov 2003 Location: Gloucestershire, England, UK	Can you trace from the output terminals for the blown channel back to where it connects to that board mounted on the main heatsink? I suspect just-functioning output transistors. You can diode test them in situ, but I wouldn't bother as they will probably read OK. If you really want to check them, measure all the other ones as well and compare readings. You may have a tough job hunting down exact replacements... They will probably be 2SCxxxx and/or 2SAxxxx devices.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)