Help! - Fender Frontman FM212r - Repair Advice needed (much apreciated)

Discussion in 'The Squawk Box' started by gl3nnium, Nov 8, 2017.

  1. gl3nnium

    gl3nnium Senior Member

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    Hi everyone. i just bought a Fender Frontman FM 212r amp that needs some repair work.
    Im looking to change the grille cloth to a classic grey, but also more importantly I need to replace 5 pots. The pots still function fine but the metal pins holding the knobs have been completely snapped off.
    ive included a picture.
    I need to replace....
    1. Mid Pot for the clean channel
    2. Bass Pot for the clean channel
    3. Mid Pot For the distorted channel
    4. Bass Pot for the distorted channel
    5. Reverb Pot

    I've looked at the schematic but i cant tell what pot is what and the part numbers.
    I don't know if one type of pot will work for all 5 or if i need to use different pots either.
    Can anyone please help me on what pots and model numbers i need?
    Also where i can order them online....Any help/advice would be fantastic because its a great amp but i have no idea on which pots (part numbers) i need and the best place to get them....thanks in advance for your awesomeness.
    Fender Amp 212r.jpg
     
  2. Cjsinla

    Cjsinla Premium Member

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    Those pots are probably not all the same value. The part number isn’t as important as the resistance of each pot and many times they are labeled. Take a look inside but don’t touch anything unless you know what you are doing. I would start by looking to see how complex the job looks once you get it open. If you can identify what the value of each pot is you can probably order new ones from any number of suppliers. If it looks like a nightmare inside, i would take it in. Remember that amplifiers can store enough voltage to kill you even when they are unplugged. If you are unsure of what you are doing you should ask someone to help you with this job. Also, how good are your soldering skills?
     
  3. gl3nnium

    gl3nnium Senior Member

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    Wow that's good to know about the danger factor. i was pretty much going to buy replacement pots from Fender or a licenced dealer and then get my guitar tech to do the soldering. Im just terrible at deciphering schematics. Ive included a pdf of the schematic if anyone out there is good with this stuff.
     

    Attached Files:

  4. gl3nnium

    gl3nnium Senior Member

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    As an update to this. I did find it curious that so many of the dials had snapped. It seemed a weird co-incidence. A few minutes ago I very carefully pulled the plastic dial of one of the knobs off to see what shape the shaft was (d shape or round). The whole dial snapped off just like the other missing 5. Im going to have to replace all 10 pots now because the ones on this amp are so weak and poorly designed. In all other respects this is a good amp but for fucks sake - Fender put some shitty dials on this model - its shameful. I will get inside the amp tomorrow and find the values of the pots so I can get some quality replacements (trying not to get electrocuted)....this really puts me off Fender in general though. They made the best gear in the world once...what happened?
     
  5. Cjsinla

    Cjsinla Premium Member

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    They still make good stuff but the good stuff is expensive. Many companies have to cut costs to stay competitive.
     
  6. Cjsinla

    Cjsinla Premium Member

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    I can’t see pots on any schematics. Is that amp solid state? Were the shafts on those pots plastic or something?
     
  7. Cjsinla

    Cjsinla Premium Member

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    Ok, figured out how to read pots on a schematic. Maybe some of our more learned forum members can chime in. @Leña_Costoso @Splattle101 @Soul Tramp

    This pic shows bass pot at 250k, a treble pot at 100k, and a mids pot at 50k.

    0BBC5F2F-E546-4EC2-A14A-991518D0C696.png

    This pic shows a Reverb pot at 50k.

    B5E8CE18-0880-4656-AC1A-CC46EE0E0CCE.png
     
    Last edited: Nov 9, 2017
  8. Cjsinla

    Cjsinla Premium Member

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    Found more info on the other channel’s pots, 50k treble, 50k bass, 5k mid and 50k volume.

    90BB88AE-6F36-4D20-B9D8-5F0D69E12B60.png
     
  9. gl3nnium

    gl3nnium Senior Member

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    Sir...you are a legend...thank-you!!! I am going to open it up today also. i found a site called amprepairparts.com which should have what i need..fingers crossed.
     
  10. DarrellV

    DarrellV Derl Ver.... ERMAHGERD!.........It's a Nerlin! Silver Supporter Premium Member

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    Outside of the shock hazards re soldering pots are among the easier things to do, IMHO.

    3 pin holes, right next to each other. all the pots are in a row.

    Once the pots are unfastened from the front of the amp its a matter of un-soldering each leg, clearing the old solder away, seating the new pot in place and re soldering.

    It would be easier to simply snip the legs off each pot and throw the pot out.

    Then you could heat each leg one at a time and remove it, instead of having to clean off all three to get the pot to come off.

    Make sure no old solder is left laying around on the circuit board when you are done.

    You can scrub with an old toothbrush or something similar to get it off the PC board.

    They make a braided wire de soldering aid to help wick up the old solder if you don't have a proper de soldering tool.

    This is on Amazon.... For example.


    [​IMG]
     
  11. Cjsinla

    Cjsinla Premium Member

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    Before you order any parts let some others comment on my interpretation of the schematic. Also, sometimes pots are soldered directly to a PCB, you need to get inside and take a look. Here’s an example of my mid-80’s Marshall. Replacement here is a little more involved. It might also mean that standard pots won’t fit.

    F40E1660-733D-4C44-B8EE-5F6F7BAA7048.jpeg

    Old Fender designs were really straightforward. The pots were all out in the open.

    5D2C43F8-113C-42CB-8831-EA75B70B423D.jpeg
     
    Last edited: Nov 9, 2017
  12. gl3nnium

    gl3nnium Senior Member

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    Thanks for all the brilliant advice. I still think i might just get a guitar tech to do the soldering rather than chance it. Ive never really soldered anything major before.
    I opened up the amp today and so I thought id put what ive found here just in case someone in the future needs the info.
    There are 10 pots from left to right on the Fender Frontman FM212r
    They are (from left to right on the front of the Amp)
    1. Volume Pot - B 50k
    2. Treble Pot - B 50k
    3. Mid Pot - 15A 5k
    4. Bass Pot - 15A 50k
    5. Drive pot - 30C 100K
    6. Volume Pot - B 100K
    7. Treble Pot - 30C 100K
    8. Mid Pot - B 50K
    9. Bass Pot - 30C 250K
    10. Reverb Pot - B 50K

    The pots have three pins that go directly into the circuit board
    Ive included pics of what i found and exactly where they need to go.
    Seems like a straight forward soldering job for someone with the right skills.
    Hopefully the thumbnails below will be able to help someone in future and save them a bit of trouble.
    The numbers above the pots correspond to the numbers ive put on the front of the amp so what someone needs and its purpose and position are clear.

    3.jpg 2.jpg 1.jpg
    Pot Close-up.jpg amp labels.jpg
     

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