The patient on the operating table....
Back in May 2012, I posted that I was getting a buzz/rattle in one of my 3.6Rs from a loose (lifted) wire. I researched the repair topic here and found a wealth of information posted by the regulars.
I'd like to pay back everyone who's ever posted on the topic by outlining my detailed repair process notes from this weekend, and posting some pictures along the way. Maybe it will make the process a bit less daunting for the next person who has to face this. I hope this will stay in the archives for a while.
The disassemble-and-repair process took me about three hours, going really slowly and taking notes. The next day I reassembled, which was 1.5 hours, again going slowly. I was somewhere between fascinated and frightened as I took apart a very expensive speaker to go fix it with $10 of glue and solvents.
I used Goof-Off as the solvent, since it's acetone and xylene, and DAP Weldwood contact cement, since everyone here uses that and it thins with xylene. The repairs seem to have held, though I'm betting if I open the other (good) speaker I'll find something pretty similar in the near future.
Here we go. Again, thanks to all who have posted on the topic and I'd like to help create a database for future owners.
Magnepan 3.6R – Loose Wire repair (June 2012)
1. Lay your speaker on padded work surface face down.
2. Get a bunch of small Ziploc bags and keep component screw sets separate as you remove them.
3. Put in protective tweeter strip. Remove Magnepan ID plaques slowly. Unscrew tweeter assembly. Unclip connector plugs top and bottom. Remove tweeter assembly carefully and store safely.
4. Remove crossover box with support-strut and screw; label the screw hole w/ sticker on fabric
5. Remove speaker stands and their bolts; label the two sets of bolt holes w/ sticker on fabric
6. Labeling holes will keep you from trying to send wood screws where they don’t belong, on reassembly!
7. Pull out two white plastic footsies. They’re not screwed in. They’re like big thumbtacks.
8. Unscrew the main screws: Top, bottom, both sides, and between the tweeter strip and the main panels.
9. Your speaker will now separate like halves of a clamshell, front panel and back panel.
10. Lift off the back panel carefully and store upright.
11. Lift up the front panel carefully – it’s a bunch of semi-loose wood strips connected by the front sock – and store upright. I taped the wood strips together for safety.
12. Return back panel to work surface, as it was, facing upward.
13. Remove fuse panel screws and gently work it through the hole in the fabric sock. You want the sock to be over the panel, not under it.
14. Loosen the fabric on both sides of the tweeter strip. It’s held down by double-stick tape.
15. Pry loose and remove the first set of staples on the bottom edge of the back panel that hold the open end of the sock in place. Loosen fabric. Surprise! There’s another row of staples after those! Pry loose and remove. Suggest you pry up all of them in a row with a straight screwdriver, then pull all of them out in a row with pliers. Very tedious.
16. You should now have the back panel’s sock ready to remove.
17. Flip the back panel over on the work surface. Mind the fuse panel – it’s loose.
18. Lift the bottom edge of the back panel a few inches, slide or roll the sock up the panel. Wedge, prop or support the panel up off the work surface. Keep sliding or rolling the sock up the speaker, carefully. Go slowly and gently. You don’t want to snag any loose wires.
19. When you get to the top of the back panel, consider if you really want to take the sock all the way off. I left it wadded up on the last 3-4 inches of the panel.
Repair: There’s your Maggie 3.6, ready to operate on. Look for loose wires not only around the buttons, but anywhere along their runs. Use back-lighting (i.e. bright light facing you) to help you see lifted wires.
20. Clean any loose wires gently with Q-tips in acetone. I used a small bottle of Goof-Off, which is acetone and xylene.
21. Brush DAP Weldwood contact cement on loose wires especially their underside and the Mylar base. Let dry 15 minutes minimum, 1 hour max per label.
22. Nasty solvent vapors from both the acetone and the contact cement. You got good ventilation?
23. Press glued wires gently down to Mylar base and they’ll stick. For seriously raised wires, like around buttons, better to push them sideways and down than try to keep them “straight” and risk a crimp or break.
24. I let the repaired wires dry and harden overnight. Take a break. You’ll need it, for reassembly.
Reassembly: Flip back panel over. Generally, reverse this list, with these tips:
1. Keep back panel’s bottom edge wedged or propped upward as you gently slide the sock back down.
2. Mind the loose fuse panel! Work that panel back through the hole in the fabric so it lies on top of the fabric again. Screw the fuse panel back in place after you’ve stapled the bottom edge of the fabric sock back in place (#4 below).
3. Along the tweeter strip channel, you need to re-attach the fabric. On mine, the double-stick tape had dried out. I used a Glue Stick, the simple water-soluble stick from your office supply store, meant for paper and light fabrics. I applied Glue Stick both sides of the channel, right on top of the old tape, and that held the fabric nicely until I re-attached the tweeter assembly.
4. At the bottom of the back panel, when you’ve got the sock down smoothly: I used the Glue Stick again on the wood of the bottom edge. It holds the fabric in place neatly. Then I stapled through the fabric with the staple gun. No drama there.
5. When you lay in the tweeter assembly: Remember, there are two connection plugs at top and bottom. Align the screw holes top and bottom before doing the middle ones.
6. At bottom of panel, you’ve now got a lot of holes. Try to lay the sock’s existing holes over the screw and bolt holes. But you’re smart – you labeled the fabric with tape to mark which holes are for the stand bolts and the crossover box support strut. Everything else is for those big wood screws that join the front and back panels.
You should be good to go now, and you will have learned a lot!
I can't seem to get more than one picture to display in this post, so here are the direct links:
Lifted wire:
[IMG]http://i76.photobucket.com/albums/j34/doublestop75/Liftedwire2.jpg[/IMG]Careful with that fuse panel, Eugene: [IMG]http://i76.photobucket.com/albums/j34/doublestop75/Fuseholder.jpg[/IMG]
Trouble at the button: [IMG]http://i76.photobucket.com/albums/j34/doublestop75/ButtonTrouble2.jpg[/IMG]
Front panel is see-through: [IMG]http://i76.photobucket.com/albums/j34/doublestop75/Frontpanel.jpg[/IMG]
Edits: 07/02/12
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Topic - Magnepan 3.6R repair steps (and pix) - K-wey 17:58:06 07/02/12 (4)
- RE: Magnepan 3.6R repair steps (and pix) - yawg 04:58:05 05/21/18 (1)
- RE: Magnepan 3.6R repair steps (and pix) - josh358 07:15:08 05/21/18 (0)
- RE: Magnepan 3.6R repair steps (and pix) - triamp 05:02:03 07/03/12 (0)
- RE: Magnepan 3.6R repair steps (and pix) - tyu 04:16:03 07/03/12 (0)