Lexicon MC-12 Power supply

Discussion in 'Home Theater & Video' started by pfigg, Oct 28, 2013.

  1. pfigg

    pfigg New Member

    Messages:
    38
    I'm the original owner of my first generation (non-balanced) Lexicon MC-12 Cinema Processor. I've heard and read that the power supply in these units often fail and need replacement.

    I just got off the phone with a rep from Lexicon. He discounted my concerns, stating that (in general) he know's of no vulnerabilities with the power supplies in these units. That's fine, and it was good to hear. OTOH my unit is about 10 years old and I think it's safe to say, considering this thing is essentially "On" 24/7 - the power supply will eventually need to be replaced.

    I've been inside the unit to upgrade it. Never had a problem with it. I'm sure I would be able to replace the PS with no problem.

    The Lexicon rep. would not give me any information about the PS (part#, etc). There is an authorized service center in my area, and the Lex. rep. instructed me to contact them if my unit was ever in need of service.

    I've also heard that the PS in the MC-12 is not a proprietary Lexicon part and a replacement can be purchased from various electronics supply dealers.

    I have no idea if this information is accurate. Does anyone have any specific information on a replacement PS, and if so - where I can pick one up? I guess I could call the service center and try to convince them to acquire the part and sell it to me. May be wishful thinking ...

    thanks.

    -paul.
     
    Last edited: Oct 28, 2013

     

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  2. Gannon

    Gannon New Member

    Messages:
    5
    Location:
    Detroit
    I know this is an ancient thread, but I found it while searching for a solution to my MC-12b's untimely death.

    Sager.com has the OEM power supply...from a company called EOS Power...with the part number LFVLT110-4302.

    Ordered mine for under $80, although they haven't told me what the shipping is going to cost.

    EOS also has what they call a "Medical" version of this, with model number LFMVLT110-4302...but the specs are identical. Perhaps it is built with a tighter-spec on parts?!

    Hope this helps someone else.

    Cheers,
    John
    Detroit
     
  3. chadnliz

    chadnliz Addicted Member

    Messages:
    5,571
    My MC8 went up in a tiny wiff of smoke and now the red lamp just blinks, was it likely the power supply? I've moved on but it was a pretty adequate 2c pre. Still have it thinking maybe there is affordable hope.
     
  4. bayareajohn

    bayareajohn New Member

    Messages:
    1
    Let us know how this works out with that part number. The same part number but ending in 1 instead of 2 has been suggested elsewhere.
    The spec is different on the two... the 2 version is 5 and 16 volt. the 1 version is 5 and 12 volt.
    Did you get the number off your actual failed supply or somewhere else?
    Thanks
    J
     
  5. crwilli

    crwilli Active Member

    Messages:
    341
    Location:
    Eastern PA
    I have replaced the power portion (not sure exactly what it was) on my MC1. I don't remember the details but it was a well known issue for these units - lots of posts on A'gon

    It was rock steady on standby power until I had to unplug the unit and had to cold start it.

    The good news it is a cheap and easy fix. I found a shop in Singapore that charged me about $150. (I was living in China at the time so this was a godsend). I am on year 8 of the new unit with no issues.
     
  6. Gannon

    Gannon New Member

    Messages:
    5
    Location:
    Detroit
    Success!

    Finally got it yesterday...I'm too cheap to pay for quick shipping.

    Installed it, just got the system reconnected...and it all works perfectly.

    Total landed cost, $93.73.

    I did get the part number directly off the old one. Didn't even think of searching for the OEM source until Lexicon pissed me off.

    Seems to me that companies should always support a box that has their name on it.


    Cheers, anyways,
    John
    Detroit
     

     

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  7. allhartfidelity

    allhartfidelity AK Subscriber Subscriber

    Messages:
    173
    Location:
    Washington State
    Anyone happen to know where i cn find the xlr ballanced pinout for the mc12?
    Common seems to be pin2 hot, but i dont know if this is the case. My Krell amp is this way, trying to make sure its compatable.
     
  8. whoaru99

    whoaru99 Epic Member

    Messages:
    40,951
    Location:
    LoTL
    I'd wager an AK membership it's pin 2 hot. Regardless, it's compatible either way.
     
    Last edited: Jul 29, 2016
  9. pfigg

    pfigg New Member

    Messages:
    38
    Well, I knew this day would come. By the way I am the original poster in this thread ...

    Last night I powered down my MC-12 (non-balanced ver.3.14) for an extended period of time in order to remove/service a tape deck. 6 Hours later when I attempted to power up the MC-12 - nothing but the notorious yellow flashing light on the front display panel. I'm guessing the power supply has (finally) failed ...

    Can someone please confirm this EOS Power LFVLT110-4302 available from Sager is a suitable replacement? Again I stress my unit is the standard MC-12 (ver.3.14) and not the balanced version. It has come to my attention that my particular model uses a different power supply than the balanced version and/or the newer "HD" models.

    I'm weighing a few options:

    • Attempt to re-cap the failed PS myself. I've done this before, mostly on tape decks and a projector.
    • Remove the failed Power Supply and ship it to an authorized technician for repair. Frankly I don't want to ship the entire unit.

    Best case scenario is the Sager OEM will work. If so I'll order it and handle the repair. I just need to know if it is compatible with my particular unit.

    I appreciate everyone's help and insight, so thanks again.

    -paul.
     
  10. pfigg

    pfigg New Member

    Messages:
    38
    I pulled the Power Supply last evening. Not difficult at all. I was informed by an authorized technician that there is a current compatible replacement. However, they expect me to ship the entire unit to them and probably pay upwards of $500 to connect 2 plugs and tighten 2 screws. No way.

    I emailed the Japanese manufacturer. I doubt it's still available. If I cannot convince Lexicon to simply sell me the replacement I may ask around for someone who would be willing to re-cap mine. I can probably do it myself. We'll see ... [-paul.]

    [​IMG]
     
  11. pfigg

    pfigg New Member

    Messages:
    38
    Just a quick update. My MC-12 is back up and running. I replaced all the clustered electrolytic caps located at the far right in the pic above. I also replaced the centrally located 150uF 400V cap. Total cost was less than $30. I plan to document the process (board characteristics, etc.) and supply a parts list. I will say the most difficult aspect of the repair was the removal of the old caps. There are traces on both sides of the circuit board. I did manage to rip out 2 copper pads. Luckily they were not linked to a trace on the suspect side of the circuit board.

    -paul.
     

     

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  12. kevd

    kevd New Member

    Messages:
    14
    Hi Paul,
    It's good you got this to work. I'm going to repair mine as well I think. Using the later "EOS" supply looks like it will require a harness modification to work in the older units like yours and mine. As you know Shindengen discontinued these in 2015 and I've been looking for a compatible replacement but in all cases there are modifications to be made or size constraints. If I come up with a mod that will allow the newer EOS supply to work, I will post it.
    Thanks,
     
  13. allhartfidelity

    allhartfidelity AK Subscriber Subscriber

    Messages:
    173
    Location:
    Washington State
    I have 2 new power supplies (not the computer grade ones)
    For the mc12.
     
  14. allhartfidelity

    allhartfidelity AK Subscriber Subscriber

    Messages:
    173
    Location:
    Washington State
    How did this information that the standard power supply would not work in the newer mc12hd?
     
  15. kevd

    kevd New Member

    Messages:
    14
    I just finished my older MC12B last night. The newer supply is the EOS, mine is the older Shindengen. I modified a new EOS to retrofit it into my unit, works like a charm. Here are some pics of old vs new with wire harness changes.
    Kevin

    IMG_4200.JPG
    New power supply is on the right
    IMG_4157.JPG
    The two connectors that connected to the old supply
    IMG_4196.JPG
    Hardware needed for modification
    IMG_4199.JPG
    Mounting of standoffs
    IMG_4185.JPG IMG_4186.JPG
    Removing and inserting wire and lug
    IMG_4184.JPG
    Completed 12 pin connector
    IMG_4181.JPG
    Line in connector with leads reversed
    IMG_4190.JPG IMG_4192.JPG
    Additional info in response to question below. Sorry I didn't put together detailed DIY, but this isn't to elaborate to change, I'll highlight the changes below.

    - Use (4) 3/8" M/F standoffs with (4) 3/8" long 4-40 screws for mounting the EOS supply. I used (4) flat washers under the screw head and (4) nuts with integrated lockwashers for mounting to the metal shroud. In the future it makes it easy to remove the supply for service without taking anything else apart.
    - Use (1) Molex PN 09-50-8121 12 pin connector to replace the two existing connectors
    - Using the pinout from the datasheet you have to rearrange the connections, remove each Molex prong by depressing the small tab with a small screwdriver or Xacto knife enough to release it from the housing and reinsert it in the appropriate 12 pin connector location until it "clicks" in and locks. See images for color code and respective locations.
    Red wires, +5.1V
    Black wires, Ground or "RTN"
    Yellow, +16V
    Grey, -5.1V
    Blue, -16V

    - You have to reverse the line in connections on the connector to accomodate the new supply, the plastic header is reversed. The brown is "Line" blue is "Neutral". The board is labeled, as well as the documentation, for the supply.

    The Molex connector is only $.76 at Digikey or at other suppliers, so only a couple of dollars in parts to do this and you mount the new supply. Also, I used the medical version because that's what was in stock, LFMVLT110-4302. Either will work
     
    Last edited: Aug 8, 2017
    Hipocrates and allhartfidelity like this.
  16. MannyE

    MannyE Exterminate! Subscriber

    Messages:
    4,797
    Location:
    Miami Beach
    Nice to see you guys were able to repair the preamps. It sucks that Lexicon is "orphaning" products they could easily help out with. Thiel was only too happy to send out surrounds for 30+ year-old speakers (04a) and even ATI, which bought the remains of B&K bent over backwards to help me fix my Reference 50 pre amp (someone over there found out about a guy that bought the remaining stock of proprietary ICs and called me with the information). Polk Audio, same thing... the guy went to the warehouse to find an ancient (30+ years) NOS part he thought he had seen and again, called back to let me know he had it.

    To be such dicks that they won't even tell you where to get an OEM part or at least sell you one at a reasonable markup is unacceptable when they are a high end, low volume manufacturer. Good to know when it's time for me to spend my hard-earned money.
     

     

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  17. allhartfidelity

    allhartfidelity AK Subscriber Subscriber

    Messages:
    173
    Location:
    Washington State
    That's great. From what I can see, the differences are the plugs is that right? If you installed a different plug can you supply information as to where you got the new plug, or give a short rundown description of the pictures and what I am seeing? I have the older mc12 non balanced, that I got the numbers from to order the new supply. I also have a newer mc12hdb that I was hoping to fit. I did 2 otjers in the past that were the same, so it is helpful to see this posting to know what I may be up against. Thank you for posting
     
  18. twiiii

    twiiii Addicted Member

    Messages:
    5,626
    Location:
    west Texas
    I installed a bunch of MC 12s and the last time I checked most had been replaced. Not because of failures but because more advanced electronics were installed. At the time I thought the MC was a contender for being the best. But a lot has changed since then. We never used Lexicon amps. Mostly QSC in commercial installations. Homes were what ever the customer selected from Yamaha, Marantz, B&K, Crown and Mcintosh .
     
  19. kevd

    kevd New Member

    Messages:
    14
    No problem, I added some details above. Let me know if you have any other questions.
    Kevin
     
  20. proufo

    proufo New Member

    Messages:
    1
    Hello all. Glad to be here.

    I just got an MC-8 that had the power supply replaced (using the one discussed-here). I removed it and I could swear I put everything as it was before. But the fuse blew -I'm hoping nothing else got damaged downstream in the unit.

    Any ideas on what could have happened?

    Two things that come to mind is that maybe one of the leads going to the on/off switch was not making contact, or that the leads were reversed. I find it hard to believe but it's a possibility.

    My first idea is to replace the soldered in fuse and try again.

    Many, many thanks in advance.
     

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