• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Marantz 1040

Hi Guys. Quick question. Could the power switch on front panel of the unit have something to do with the fluctuating dc offset? Interestingly i tried to get some electronic spray into the power and speaker switches and it made a significant difference on the DVM readings. It is hovering around -4 and +4 mv. Goes to 10mv every now and then but not as bad and high as before. Just tried this as I saw j707 comes from the power switch. Dnt know if I'm crazy to even think this?
 
Hi Pete. Thank you for all your help so far . I trust in your expertise, however the difference made by just spraying the power and speaker switches has made such a huge difference I'm hoping you might be able to see some direction for me in this situation. I mean the DVM readings went from fluctuating between 23mv and 160mv to fluctuating between 0mv and -4mv. Is
there a way to be able to eliminate the switches as the problem. After spraying the switches the readings still fluctuate but leave it standing and it continues to drop and eventually just fluctuates between 0mv and - 4/5mv. I read a thread on AK on how to clean these switches but I attempted it and the barrel won't come out. Trying to force it I'm afraid will damage the switches. I just did my spraying through the openings I could find on the switches. I'm sure the findings above will help you steer me in the right direction please?
 
Hi Pete, just a thought. I am assuming the power switch merely opens and closes a circuit. Is it not possible to remove the wires from the switch and connect them direct to each other to see if it eliminates the problem to know for sure it is the switch?
 
Hi Pete. Separate switches for both main and ambient speakers. I bridged the switch and still doing it. So it not the switch after all or maybe it is due to multiple problems. I don't know where to next
 
Hi Pete yes I did but no difference.

Removing r701 showed main amplifier is ok. How do I block the feed of PE03 and PE05 to PE01. Would doing that isolate where the problem lies as power supply and main amp is ok leaving only those sections.
 
Its not on the manual I have as well but is mentioned. See the snippet from the manual I have attached. I am assuming it is the board along side PE01 and a tiny board mounted underneath PE01. Please forgive my photography efforts attached 20200904_210031.jpg 20200904_211215.jpg 20200904_211236.jpg 20200904_211310.jpg 20200904_211455.jpg
 
looks like the p400 board to me .phone eq board ..easy to cut off .simply switch to aux or anything that isnt phono .
looking at pe01 there is a shielded wire or wires .red and white and shield .if these go to the filter switch swap red and white and see if dc offset issue switches sides . if so it confirms its the pe01.

there was a clue there as designation numbers begin with 4 .
 
Thanks Pete. Just to confirm are these the red and white wires to stop around.

Dnt want to put something ass backwards like I did before I got on this forum :beatnik:20200904_220604.jpg
 
looks like they go to the vol pot so wont do anything if swapped ..je01 and 2 if i am looking at it correctly .
 
Ok will confirm it does go to filter switches before I give it a try. Just out of curiosity how would it confirm it is PE01 as the issue. I mean my understanding which is obviously wrong tells me that if I swop the wires I'm swopping that feed and if the issue changes sides then the feed is the problem.

Asking because I'm really eager to learn and would appreciate your teaching.
 
white/green white/orange wires . are the 2 i was thinking of . but they a wrapped and best leave as they are really ..
i am fairly certain the problem is on the pe01 board . could be a transistor or a cap .
 
Ok. I dnt have transistors on hand but I do have the caps. Let's change them one at a time
Tomorrow and check to see difference each time. Hopefully it will be a winner but in the meantime can you possibly suggest transistors as I cannot get these in the parts list locally that's why I don't have them on hand already.

P.S : I tried hairdryer on the transistors again today
And the readings went all over the place but came back when I took away the hairdryer. 20200904_175049.jpg
 
You must log in or register to reply here.
Back
Top Bottom