how to disassemble this AC Adapter?

Have a Battery Technology, Inc. AC Adapter for an IBM Laptop IB-PS365, 55W 16V 3.4A

The thing has gone intermittent. By slightly flexing the case, comes back on, so idea is to disassemble, solder traces and be up and running instantly.

but...how to disassemble?

Anybody done that?

You could try dropping on a hard floor, or using a hammer, pound on the corners abit all around wallwart where the seam is. I know this sounds crude, but often it works. Another way is to use a dremel mototool with a cutoff disk and cut along the seam all around the wallwart.

good luck,

Shaun

Sure. I do it all the time. However, I've rarely found an intermittent inside. It's usually a broken cord or plug. Be sure it's not the cord before proceeding. I use 3 methods (in order of increasing brutality).

1. Stuff the charger in a bench vice with some wood blocks for padding. The glue line should be facing the jaws. Apply pressure until you hear a cracking sound. Hopefully, it's the glue line, not something inside. If see a gap, use a pry bar (I use a bicycle tire tool) to open.

Others have suggested putting it in the fridge overnight, which will make the plastic and glue more brittle. Seems reasonable, although I've never tried it.

1. Find a masons chisel.

Place the business end along the glue line and start pounding. The idea is to crack the glue, not the case.

1. If the above fail, it's time to saw it open. I use a hack saw and bench vise. Saw along the glue line half way through the plastic. Again, the idea is to crack the glue line, not cut all the way through. Reassembly will require some glue, and cosmetic (black electrical) tape to hide the damage. If I can get half way through, the case will usually come apart. This also works well for battery packs.

If all else fails, you can get replacements on eBay for about $10-$15.

More:

First is to remove any sticky labels that may cover a securing screw. Refining point 1 , place in vice with the weakest point in the line , where one of the cables exits. A guitar plectrum is best to start with as a pry-bar as minimum damage, progress to screwdrivers etc later.

I didn't immediately start prying, because one end, where the AC cord connector is, seems to flex back and forth, not at all like it is glued rigidyl in place. However, the other end, where the power cord continues to the laptop, is very rigid, like glue,...or a screw.

By pressing around the metal stick on label, a small detent at that end appeared. Thinking it was a mounting screw, I removed only the small round bit covering the screw and that revealed what looks more liike a small pot screw head - for adjusting voltage?

From Jeff Lieberman's excellent URL, I started prying and VOILA! The case is indeed plastic detent, not glued!

It literally pops apart. The tool in this case was the very thick HYDE joint knife, the one that is not flexible [too thick] and tapers to a knife edge. But be careful more than once I've slipped with this awkward tool and it is a knife edge, always plan for a slip and envision the path the knife will travel, ...else it takes several weeks to recover.

Now inside the PCB is covered with a copper foil for EMC, so can't get ready access to the traces. And, yes, the screw is a pot adjustment.

But, hey the case is NOW open

I don't see anything immediately. but glued down fish paper and copper shield block a lot. The unit used to fail with the LED simply going OFF. If ON, unit was ok. Could be a lot between the AC mains and that LED, though.

and

re

As someone else suggested, an intermittent power supply is almost always caused by a defective cable. Regardless, now that it's open, you can touch up all the solder joints, and put an ohmeter on the power cord.

I was actually suspecting the PCB connector for the AC mains cable. All that flexing into the right angle mount with NO strain relief has got to take its toll. Seemed likely there would be cracks around the mounting/electrical pins.

I hate tearing into the fish paper/copper foil wrap. Some of the best workmanship in shielding I've seen although it's incredible the shield is connected via a 3/4 inch long 22 Awg solid wire to a point on the PCB where the PC cable connector is mounted. However, sometimes NOT doing something right can suffice, especially on small packages.

Good idea. However, I have yet to see such a screw on any laptop power supply that I've torn apart. There usually isn't any room for the required plastic pylon inside. There is also some safety rule (double insulated???) that requires that the unit NOT create a shock hazard by allowing the user to open the case. That's why they glue the case shut, and not just snap or screw it together.

I beg to differ. The ends are usually not very strong or well secured. Compressing the plastic case at the ends is likely to break the plastic, and still leave the long glue joints along the sides intact. Best to break the long side joints first, and the ends will just fall apart.

Yes, that should work. However, at $3/ea, I'm not thrilled.

I think the favored tool is a "spudger" from telco tools and the favored tool for prying apart Apple products. Whatever works that won't shred the insulation and shielding inside. Avoid anything with sharp edges, such as a screwdriver.

The LED is across the output. If the cable or connector is shorted, then the light will go out. Look for a short at the plug end of the cable or loose shield wires on the output cable.

where

Just this last Saturday a Boss PSC 2306 9V, 1A smps "wall wart" psu. Under the label, a recessed 3mm a/f screw. After that squashed across cable-weakened short side end in a vice , then other short end, then long sides and plectrum.

A trick I often use on suspect leads is to use a SLA battery and a H4 bulb with one or both filaments, often an intermittent lead fails to show up on an ohmeter or continuity tester, the over 4A (or 8A) will make most intermittent breaks permanent.

Needless to say the OP would be well advised to unsolder the lead from the PCB before applying this proceedure.

They often pour potting resin in the screw recess to hide the screw head and make it nigh impossible to get at.

The case did NOT seem glued, simply very strong plastic detent fingers.

Changed out the AC cord, made NO difference. Same symptoms. Used the bottom half of the case simply to hold the assembly and reduce shock potential - seems unlikely with the shield attached to the PC connector shield. Then pressed around on the top and found that pressing near the LED [away from the AC mains port and closer to the PC port] would cause the LED to momentarily come on, but not stay on. Have no idea what's flexing to cause this. But need to remove the fish paper/shield assembly to get good access.

Have to say that this packaging is a marvel to behold. It looks like the parts were poured into the volume, completely filling it up.

The fish paper, between the copper shield and the PCB seemed to be glued with a simple 'tacky' type glue and separated easily with the same 'knife' edge tool, without damaging/distorting its shape.

more later

Found it! Cold solder joint in the middle of the PCB to a large gauge through hole component. Don't know to what on the other side, but the wire looked 20 - 22 Awg size and had a neat fuzzy line around it to the cone of solder, which 'looked' good. Evidently over time the gap widened until intermittent and then open.

Culmination: Case SNAPS apart. Fish paper/copper shield easily opened. Cold solder joint in the middle of the PCB.

All back together now and working!

Thank you everyone for suggestions.