Fix your expensive Boss PSA AC adaptor

[Processaurus]

These expensive Boss adaptors always seem to break the wire right up by the wall wart end (sometimes in a way you can't see it).  Its awkward to splice onto the wire if its almost were it enters the wall wart.  Here's my technique for fixing them, the revelation being that you can open them without hurting them:


Unscrew the hex screws
Take a big ol flat head screwdriver or chisel and hammer and tap kinda hard (be brave) and then twist, along the seam around the sides and top.  It'll pop the glue and you can open it up.
Unsolder the bummed out end and cut it were you think its good.  You can beep it from the plug end by sticking a needle through the insulation (like automotive people do when they can't get at the bare wire ends).  Or just cut off 4" and test it because it almost always breaks at the plug or wall wart, seldom in the middle.
Put some heatshrink on the wire (to be a new strain relief).
Tie a knot about an inch from cut end.  This knot will go just inside the wall wart, and will make it so if it gets yanked it won't be on the solder joint.
Solder the new ends on.  Note the dashed white conductor (the tip) goes to minus inside.
Do the heat shrink up by the knot.
Put the plastic shell back together.  I stuck some hot glue in there to seal it up and make a gooey looking strain relief.  Now no one will want to take it.
Its probably smart to check it with a DMM before using it.


Pre-forgive yourself and con your friends into giving you their busted ones, there always seems to be one around well broken in practice spaces.  This would also work if you just wanted to replace the chinsey wire with heavier gauge zip cord like 1spots use, then you can decide how long you want it to be, enough length to go back to where your amp plugged in is incredibly handy for scarce outlet situations.

[MikeH]

This is a good thing to know.  I often have to repair them at the plug end too.  I just cut off the molded plastic, strip back some fresh wire, resolder, and then cover with a big piece of shrink tubing.  Works like a charm.

[stm]

Nice DIY repair report, Processaurus!

I am curious about the inside: do they have a standard LM7809 voltage regulator or something fancier/cheaper?

[Ben N]

Nice. I have to dig out a bad keyboard PS I have--that may be the ticket.


Thanks,
Ben

[Pushtone]

Thanks!

Mine stopped working this weekend.
I wasn't brave enough to crack it open after removing the hex screws.
The heat shrink would be something I would forget to add. The pic is a big help.
Thanks for the post, timely!

[Mark Hammer]

Strain relief...you can never have enough of it.

[BDuguay]

I just fixed mine about a week ago for the same reason you mentioned. I added a peice of silicone tubing for strain relief.
B.

[fikri]

Nice DIY repair report, Processaurus!

I am curious about the inside: do they have a standard LM7809 voltage regulator or something fancier/cheaper?

I think so...

[The Tone God]

I am curious about the inside: do they have a standard LM7809 voltage regulator or something fancier/cheaper?

I have shots somewhere of the insides of one. It is just a basic 7809 circuit. Nothing special. I'll see if I can find the pics I have and post them somewhere.

Andrew

[Gus]

Just be aware that if anything goes wrong and your house burns down or someone elses house with the work you did on the power supply.  You do have to break the weld so some force is needed, maybe a part(s) get damaged. 
By openning a unit like that I wonder what an insurance company would do.
Be careful you might save some money but you are openning yourself up to liablity problems.

[kvb]

I cracked one of these open a long time ago. I figured it didn't work so what did I have to lose?
No screws. I think I carefully used a razor to open it. Now the thing is held together with a mess of electrical tape. And, now I have another to fix.

As far as dangerous wall warts go, I just don't leave it plugged in all the time.  Besides these things sometimes just melt down on their own, don't they?.

Anyone have experience with that?


edit to say: Thanks Processaurus for the tips on strain relief.

PS:  I love hot glue.  Maybe I'll get all crafty with mine and turn the wart into something that looks unique or odd.

[Pushtone]

Just be aware that if anything goes wrong and your house burns down or someone elses house with the work you did on the power supply.  You do have to break the weld so some force is needed, maybe a part(s) get damaged. 
By openning a unit like that I wonder what an insurance company would do.
Be careful you might save some money but you are openning yourself up to liablity problems.

A VERY good point that applies to homebrew amps as well.
No insurance company will cover a fire if caused by modified electronics.

Don't forget that insurance companies DON'T want to pay claims and will use
any excuse not to. If the Fire inspector even finds modified electronics that didn't cause
the fire you still could be left hanging and homeless depending on his report which you have no control over.

My solution is to power my entire guitar works from one power bar and turn it all off when not using it.
I also plug a lamp in for a visual reminder when it's on.

A smoke alarm directly above the guitar area is also a very good idea.

[Processaurus]

Just be aware that if anything goes wrong and your house burns down or someone elses house with the work you did on the power supply.  You do have to break the weld so some force is needed, maybe a part(s) get damaged. 
By openning a unit like that I wonder what an insurance company would do.
Be careful you might save some money but you are openning yourself up to liablity problems.

I was worried about damaging the insides (and the transformer especially) too, but there is a tough lip in there that makes it unlikely you'd go through to the interior.  The glue isn't nearly as robust as normal wall warts that aren't screwed together.  I doubt many PSA's have burnt houses down in any case (they're nice as far shutting down if something is shorted out), but I won't argue over what someone has to do to get to sleep at night.

Strain relief...you can never have enough of it.

You said it... strain relief seems to be the key to lasting cords, of all sorts.  When I was done I was thinking I could have stuck a spring in there like some guitar cables use for deluxe strain relief.

[Mark Hammer]

Get yourself some heat shrink of the appropriate size/s.  Clip the wire from the adaptor as soon as you get it home.  Slip some heat shrink over the transformer end of the wire, some more over the barrel plug end of the wire, and then slip some over the solder joint once you reassemble the cable/cord.  Yeah the wire will have an ugly splice in it, but it will last you a LONG time because of the strain relief on the parts of the wire that have to bend the most.  People tend to think of heat shrink as simply a substitute for insulation, but provides excellent strain relief too when used in the right way.  I always stick a wee piece of it over the solder joints on pot lugs these days for both purposes.

[petemoore]

  Line 6's power line broke right where it comes out of the strain relief waffle by the body.
  I folded it back over the waffle, tied it with a plastic twistie, pulled the protrude's of the copper away from each other [+/- were touching where the open copper was twisted], then heated and added hot glue to the whole affair, this sealed the whole business, gave it strain relief, only took time for the glue to heat.
  The waffle type strain reliever is too sharp and tough...it can put a break in the wire just like no strain relief...but makes a great strain reliever if the wire is bent back over and fastened to it, I've done this with duct tape or electrical tape.

[darron]

hey... ot. i never got with american wall sockets.... what stops you from putting it in upside down and getting the wrong polarity, and how do the devices get earthed with only two lines?

maybe stupid questions?

thanks

[remmelt]

?? They have AC in the USA too, last time I heard

Also, adapters like these are never earthed. They don't need to be (?)

[Jeffreaux]

I took the original strain relief (waffle thing) and sliced it with an exacto knife along the seam and then the wire pulled right out. I then cut off
a few inches of wire, opened up the (waffle thing) put the wire back in and glued it with super glue and now you can't tell it was ever opened.

[darron]

?? They have AC in the USA too, last time I heard

Also, adapters like these are never earthed. They don't need to be (?)

i'm not an electrician and don't know much about it, but i know that ac still has pos and neg. if i plug my LED line tester into the power point it will only work one way, and my dmm will give me either +240v or -240v. what about grounding things like amps though where it's pretty much crucial?

pardon my extreme ignorance... i am curious though

[Paul Perry (Frostwave)]

I doubt many PSA's have burnt houses down in any case (they're nice as far shutting down if something is shorted out), but I won't argue over what someone has to do to get to sleep at night.

I think we might see more of this happening, now the California law is forcing DC adaptors to go switchmode.
I had a lightning strike take out some gear, a day later I found my internet connection was down.. tracing along, it turned out the switchmode PSU for the external modem was fried - and still hot, all this time later?? somehow it had got a partial short despite fuses. A standard DC wart (at least in Australia) has a buried non-replacable fuse inside the windings.