1. Rest in Peace Paul (Kegger) If you would like to help the family in this time of great sorrow and need, you may donate on their GoFundme page: https://www.gofundme.com/mckechnie-medical-and-funeral-fund?
    Dismiss Notice

2270 no power

Discussion in 'Marantz Audio' started by Dearslayer, Dec 5, 2016.

  1. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    Hi .... Been away for a bit working on another unit but I picked up a 2270 in Wooden case today. Seller told me it wouldn't power up and blew the fuse when plugged in and power button on. He said he had it stored away for some time and it worked before storing. This thing was so dusty inside. Must have been in a warehouse. Cosmetics are really nice overall and I had no choice but to meet the guy in the city at a gas station near his work. Like I said he already told me up front over the phone that it wasn't working and I was buying it " As Is ". Got it home and put a new fuse in the rear and put it on the DBT. Fail. Bulb glows bright, constant, so I powered it down. Dead short somewhere! So I guess I need hand holding ,and guidance on where I should start! Need help cause I'm lost as to what I should do first.

    Regards.
    GT.
     
  2. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    22,425
    Location:
    uk.. the middle bit
    first suspects are output devices and rectifiers .. might even be main filter capacitors if it was really working before storage ,,
     
  3. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    I'm only taking his word about it working before storage. He also told me he knew the original owner who he got it from and said he bought it from him that way so who really knows. So is there something I can do to determine the possibilities?
     
  4. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    22,425
    Location:
    uk.. the middle bit
    i cant remember now if the output transistors plug in or are soldered in on this one ..if plug in they should be removed and tested first ..
     
  5. Richs_Trains

    Richs_Trains AK Subscriber Subscriber

    Messages:
    613
    Location:
    Tucson, AZ
    Dearslayer, Don't know if this will help, but I had a 4230 that was shorted also and I was able to remove the AC feed to the filter caps and the DC feeds to the power amps, I then powered it on the DBT and it passed and had dial lights. I the reconnected the filter cap feed and got a short again. I replaced the filter cap and it passed the DBT. I connected one power amp and it passed DBT, connected the second power amp and it failed. Doing this I was able to determine that the filter cap and one power amp were bad. Removing the power from the bad power amp again, I was able to power up with the 'good' channel and new filter cap and got audio. Since I am not very good at troubleshooting at the circuit level, I purchased a used power amp and now the unit is 100%. Hope this helps. Good luck Rich
     
  6. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    I'll take another look but I believe they are soldered on this unit. Hahaha was hoping to not have to take it apart right away to find the problem.
     
  7. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
     
  8. wlhd1610

    wlhd1610 Penny and her new friend Subscriber

    Messages:
    1,948
    Location:
    upstate new york
    2270 outputs plug in.
    All Marantz receivers 22xx (from 2220 up) and 23xx have plug in output transistors.
    The mighty 2500/2600 are soldered.

    Bob
     
  9. Richs_Trains

    Richs_Trains AK Subscriber Subscriber

    Messages:
    613
    Location:
    Tucson, AZ
    I un-soldered at the rectifier, on the 4230, the rectifier had 4 wires, the 2 center leads went to the transformer (AC) in and the outside wires (DC+ and DC- out) went to the filter cap. I removed the DC out wires to the filter cap. As Bob pointed out you can unplug the power amps one at a time to DBT. Rich
     
  10. Richs_Trains

    Richs_Trains AK Subscriber Subscriber

    Messages:
    613
    Location:
    Tucson, AZ
    ......and on the wooden cases, I have been lightly sanding them and the applying 'Tung Oil' which brings out the grain and seals, but does not add gloss. I usually apply one treatment of tung oil, let it sit awhlie, wipe it down with a clean towel and the repeat the process and then let it sit overnight. I tried stain and finish and felt it was much too glossy, even when I used low gloss polyurethane.
     
  11. Richs_Trains

    Richs_Trains AK Subscriber Subscriber

    Messages:
    613
    Location:
    Tucson, AZ
    4230_3_11.jpg

    rectifier on 4230, outside wires feed filter caps.
     
  12. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    Been looking on the schematic to see where the rectifier is on this thing, and I feel so stupid not being able to find it! Maybe I'm in over my head on this one. The other units I've worked on were at least all working units.
     
  13. rBuckner

    rBuckner Luv 2 Restore Subscriber

    Messages:
    8,960
    Location:
    Prescott, Arizona
    It's on the bottom side, a cubic dark green block with 4 fat wires going to it. It's about 2-3cm on each side. I've never seen a bad one. First I'd unscrew the outputs (after taking notes as to what number part goes where) and test for shorts, especially collector to emitter.
     
  14. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    thanks so much. I took some pictures of that this morning before I left for work and thought it might be it but I will follow the advise of checking the outputs first.
     

    Attached Files:

  15. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    Pulled the output transistors on the RS power amp and tested. The bottom one( SJ2518) tested ok at .523. The top one SJ2517 got no reading. Left the top one out and put the unit on the DBT and bulb dimmed and I got power to the dial face which is a good sign. Turned it off and hooked speakers to the unit to see if I would get sound from the left side ( still on the DBT ). Turned it on and no sound and smelled a foul burning smell and saw a little wisk of smoke so shut it off immediately. Waited a few minutes and just quickly powered it on to see if dial face was still lit and it was but I shut it down again right away in case of damage. So bottom line is it does get power without that transistor. Gonna test the two on the other side to see if they are toast and report back shortly. The wisk of smoke and burning smell has me very worried that there may be more wrong.
     
    Last edited: Dec 6, 2016
  16. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    22,425
    Location:
    uk.. the middle bit
    if you run speakers with no outputs you did a bad thing to the drivers . maybe burned a collector resistor and a driver . if no resistor in the circuit to burn you maybe burned a driver or 2 .
    i am going of general topology here i haven't looked at the schematic yet .. but driving speakers with the outputs missing will cook the driver transistors in a few seconds if not quicker .. this is why i install powerful drivers if permissible but that is another story ..
     
  17. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    Ok sorry please excuse my ignorance but what are the drivers ? I checked the outputs on the other side and they both have a reading. Bottom being .504 and top being .462. Here's the other thing ... Shouldn't the part numbers for outputs be a mirror image the R/S top is SJ2518 /7413 bottom SJ2517/7426. L/S top is SJ 2517/7426 bottom SJ2518/7426. Also the top L/S is NPN whereas the other two were PNP. Ok so bottom line is how much damage did I do and considering I want to do a complete restoration will that fix any damage done or is it beyond that ?
     
  18. petehall347

    petehall347 the brandy coffee man Subscriber

    Messages:
    22,425
    Location:
    uk.. the middle bit
    everything is repairable .. it is my bedtime right now so i will let someone else chime in . then catch up in waking hours .
     
  19. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    Ok thanks so much for the help so far.
     
  20. Dearslayer

    Dearslayer AK Subscriber Subscriber

    Messages:
    547
    Location:
    Ontario Canada
    Planning a full resto of this unit and will place an order with Mouser soon. A couple questions first if I could. I will follow a cap list that was recommended on AK. Would it be a wise choice ( considering the one output transistor is pooched ) to include all four " new outputs" as a preventive measure and if so can someone recommend the Mouser part numbers for such to ensure I get the correct ones. Also given the fact that I perhaps ( most likely) did more damage as Pete suggest ( and I respect his expertise and knowledge) what really should be my next step considering the wisp of smoke and burning smell. Are there more measures I should take before ordering anything? I did start out feeling good about the small success of discovering the bad output and getting it to power up at least ( I am very inexperienced with diagnostics as opposed to remove and reinstall ) only to end up feeling stupid about the whole speaker hook up without the output and doing more damage. So much for a small victory I guess.
     

Share This Page