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  1. M

    marantz 2270 left channel hiss static problems

    Finally got a chance to work on unit put back all old small transistors everything works perfectly with exception of now not being able to adjust idle current on right side amp but I believe this is due to the adjustable resistor R763 being dirty and I dont have anymore deoxit as soon as I...
  2. M

    marantz 2270 left channel hiss static problems

    I will replace the old transistors I also tested every single one as I removed all tested good and no leakages I will try and work on it Sunday I will also leave the gain matched diff pair or as close to gain matched as I could get thanks again..! I will update after swap
  3. M

    marantz 2270 left channel hiss static problems

    What's strange is I did that exact thing you mentioned I swapped left to right rca and noise stayed in left channel I used ipad doing the same left right swap and no noise does that even make any sense..?
  4. M

    marantz 2270 left channel hiss static problems

    Noise is coming from my phone WTF I used my ipad with frequency generator at 1hz and sounds normal now I sincerely thank you for your insight now since I have already rebuilt left amp should I put old transistors back in or rebuilt right amp so everything matches
  5. M

    marantz 2270 left channel hiss static problems

    I will try another type of input and get back to you
  6. M

    marantz 2270 left channel hiss static problems

    No noise with jumpers in or out with no input signal applied and volume all the way max also used balance control all the way left and right no noise
  7. M

    marantz 2270 left channel hiss static problems

    And I am using a phone as my input signal
  8. M

    marantz 2270 left channel hiss static problems

    I will test that here shortly at halftime of the game and get a response back to you thanks,Marc
  9. M

    marantz 2270 left channel hiss static problems

    Apparently I didn't..? I am not an audio engineer nor do I have any sophisticated repair equipment i do have a decent understanding of electrical components and schematics and I do have a DBT and a decent DMM as stated after I replaced all caps and speaker relay on power supply I recapped and...
  10. M

    marantz 2270 left channel hiss static problems

    I do not know if bias was ok before work when I get a chance this weekend I will re-check bias as per runningdogs post I believe I measured across the wrong jumpers or revision 1 and should have used the revision 2 measurements mentioned above could bias being off affect the noise I am hearing..?
  11. M

    marantz 2270 left channel hiss static problems

    so i recently bought a 2270 that the seller stated was "working" but had been in his aunts barn on her ranch here in central california for the last 35+ years as he stated she had died in the late 80s i bought it knowing that it would probably have issues because at 300 bucks i knew i could...
  12. M

    Marantz 2270 transistors right p-750 -46vdc to relay

    also would there be anywhere else on p-750 that i should look at for the -46vdc rail getting to the relay besides h-759 remember that this is with main outputs removed on right p-750 and i still get the -46vdc after 2-3 minuets of on time when first turned on the unit comes out of protection...
  13. M

    Marantz 2270 transistors right p-750 -46vdc to relay

    http://audiokarma.org/forums/index.php?threads/2sa566-and-2sc680-substitutions.287042/ this is the link i used to order h-758 and h-759 on p-750 for marantz 2270 as it was recommended to replace both as a complementary pair so i ordered the pairs that roobarb recomended I.E mje15032g & mje15033g
  14. M

    Marantz 2270 transistors right p-750 -46vdc to relay

    i have pulled all devices from right p-750 diodes and transistors and found that at higher temperature h-759 fails allowing -46vdc through to the speaker protection relay and kicks it off this is with the main outputs removed this is why we have come to the conclusion in a previous thread that...
  15. M

    Marantz 2270 transistors right p-750 -46vdc to relay

    so I cant find my previous thread to post along with this but I need help in finding an equivalent transistors for h-758 and h-759 on a 2270 serial #33xxx right side p-750 I’m getting negative -46vdc thru h-759 with main outputs out. Should these be replaced as a matched pair and what would be...
  16. M

    Marantz 2270 works for 5 mins then click off

    Got it cold on dry ice with meter on tests great all the way until at or about 200 degrees it fails then I would put it back onto the dry ice after about 30 seconds it starts to work again so I’m assuming it’s an intermittent failure and the air can flipped upside down just wasn’t cooling it...
  17. M

    Marantz 2270 works for 5 mins then click off

    So after some unorthodox testing indeed h-759 has some issues any recommend replacements and if both h-758 and h-759 need to be replaced as a complementary pair
  18. M

    Marantz 2270 works for 5 mins then click off

    yea I had my eye on h-759 I think at this point I’m going to just start with h-758 and h-759 any suggestions as to a replacement and I should replace both as a set correct.?
  19. M

    Marantz 2270 works for 5 mins then click off

    Ok I have pulled all devices again tested each out of circuit ALL tested GOOD re-flowed entire board tested with main outputs OUT same result only this time it starts at -0.02vdc them jumps -46vdc after a few minutes then after a few more minutes it drops back to -0.02vdc and will hold for a few...
  20. M

    Marantz 2270 works for 5 mins then click off

    Ok I will do this hopefully tomorrow I have been helping a buddy move some horses
  21. M

    Marantz 2270 works for 5 mins then click off

    Sounds good I will let it sit in the warm California sun tomorrow on and running for an hour or so then hit it with spray on all devices and see what I get
  22. M

    Marantz 2270 works for 5 mins then click off

    Don’t know if this could effect these symptoms or not but the rear main 55v 9kuf cap has a relatively deep puncture in it it is not thru the outer aluminum can but as the pic shows it is about an 1/8 of an inch deep..! also the white wire on j-761 on right amp where The -46vdc rail comes out it...
  23. M

    Marantz 2270 works for 5 mins then click off

    Ok so just went back out and checked I have my -46vdc back and after just watching my meter for 10 minuets or so the voltage never goes over -46.4vdc but every now and again it drops to the correct 0.03 vdc then bounces to -22.xx or -30.xx then back down to 0.03 then back up to -46 and stays...
  24. M

    Marantz 2270 works for 5 mins then click off

    Yes c-762 is present and accounted for..! So I took the leg of that .01 cap off of j-761 just using the ground coming from j-758 amp turned on came out of protection quickly and I had a reading of 0.08vdc so I used r-762 and got reading down to 0.03vdc to 0.02vdc after about 3 minutes voltage...
  25. M

    Marantz 2270 works for 5 mins then click off

    No difference I could tell cold or hot on devices so I started studying the schematic left amp is indeed wired like this on j-758 to ground right is different there is a ground from j-761 to to j-758 I included a picture this is also where main outputs -46vdc comes from could this be my problem...
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