Repair modular power supplies

Instructions on how to break the seal on modular power supplies to fix the common problem of fatigue breaks in the cord, repair the internals, or salvage for other uses. This will violate warrantees so do this only for equipment not covered by one. Pardon the pics, I don't have a camera for this.

Step 1 The modular power supply

These come in all shapes and sizes and capacities. The arrows point to the common point at which the cord tends to break internally. Before opening it, be sure that the power supply itself is at fault, and not what it's plugged into. If you are just salvaging, this can make good practice for when you are repairing one you intend to re-use.

Comments

[skyd123]

Thanks a lot for this article.. Going to try this as soon as i reach home.. Its three weeks w/o my laptop... Thanks again ..

[advancedage]

Thank you! After my sister swung the cord around I've been without a laptop but today I got bored and found this article. Now I just need to do a little soldering and I use it again. Hurry!

[Prometheus]

To be honest, I never thought this article would be so useful to so many when I submitted it...I had been doing this for years, had been bored one day, and posted this project (oddly enough). I am glad to see that this project alone has saved many a headache for you and others, and I thank you all for your input. I hope this project continues to serve everyone as my knowledge of doing it has served me. To hear your thanks is worth more than any contest winnings to me...

[manumanu]

This guide is very very useful... I experienced the very same fault of the power cord, just near the relief and I after reading this I'm surely going to try to fix it. Thank you all. Bye from Italy

[Derin]

I would like to rent that space,for $0

[Prometheus]

Sorry, the running rate is $89.95 if you want it, $149.95 if you don't. Rate can be negotiated with inclusion of cheerleaders or asian schoolgirls. :lol:

[Valche]

I doubt I'll be taking power supplies apart any time soon, but wow, what a detailed instructable! Very good work, and I never knew that that's how some cases are sealed, good to know! Great stuff. +1

[pwilliam56]

Most of these can be saved this way. Great information. I have found that most of these cases can be opened fairly easy by placing them on a smooth, hard surface (concrete or tile,) with the seam perpendicular to the floor and the case on one edge. Take a hammer and carefully tap on the top edge of the seam. With a little practice the shock of a well placed tap will pop the glue loose. Sometimes it is necessary to turn the case over and tap on the opposing corners to break the seal all the way around. This generally doesn't scar up the case as badly as just prying it apart.

[Prometheus]

Just remember that sometimes the glue might actually be stronger than the plastic itself. The common practice is to use a glue that produces something similar to the "vulcanization effect" with rubber patches; meaning it reacts with the plastic and partially melts it to create a bond. I prefer to mar the case a little to make the repair then to introduce new problems as a result of physical shock force to the unit. I do not reccommend this method for any power supply that may possibly be transistorized, as it may do more harm than good....

[pellepeloton]

Sometimes you may have a faulty transformer and often is is the primary/ Just check with multimeter between the pins on the AC plug. If you have an open circuit, you may still be able to salvage it as there might be a thermal fuse or normal fuse inside?

[Prometheus]

Few modular power supplies have a thermal fuse on the primary winding. If it does though, it is safe to simply jump the fuse, and let the winding itself act as a fuse...if the transformer burns out again, just toss the whole thing, as the transformer has failed, causing the initial burnout, and is not reasonably-salvageable. If for any reason jumping the thermal fuse causes any breaker to blow, or anything other than typical operation, toss it...not even worth fixing. Transformer is like the engine in an old car....if it goes, the whole unit is a total loss, so just forget it and try to find a replacement.

[spinach_dip]

How dangerous is this?

[Prometheus]

Only danger is in how careless you are with handling electronics. If you cannot handle a simple power-supply repair, don't attempt this as it will get you nowhere. If you try this while it is still plugged in, you win the Darwin award... Simply put, if you don't get this, don't try it...

[xcursedx]

to many outer cases won't come unglued, so i just glue then tape them up, i also find it's better to shave down to the wire then to cut into it, i just replace the jacket with a piece of wire housing, usually the thickest i have around, i also usually lead the wire up [__].| from the housing to reduce future stress...

[jtobako]

a strip of electrical or duc tape will extend the strain relief and reduce the number of times you have to re-do the repair.

[Prometheus]

Me personally, I would use rubber hose, like that for vacuum tubing, but in cases where it is 20AWG 2-conductorzip-wire coming out, extending the strain relief has little effect. When I can, I use heavier cord from previously cannibalised units where it was a faulty transformer.

[rjones3]

Nice work on the drawings!

[Prometheus]

Thanks...Not bad for just MS Paint huh? lol

[Prometheus]

Well thanks for the comment guys. As far as scarring the case, I am fairly careful about this when I do it anyway. The idea of squeeezing the case may work about as well, but the corners usually become a problem. If this is done with care and respect, it is perfectly safe so long as you reassemble it again later...

[Vermin]

Another method for opening the case is to squeeze the seams gently in a vice. I've used this to pop many a case open without fail.