Opening Metrahit cases

[hirada]

Hi,

in case this should be the wrong subforum for this kind of question, please feel free to move.

Otherwise, as the topic suggests, I am in need of opening a metrahit xtra case. I am aware, there is a snap in mechanism at the front, I have found a picture of an open energy, but I am not sure on how to remove the cover without  braking the snap mechanism

Any ideas or tips?

Thanks

Ede

[giosif]

Hi Ede,

I'm sorry, I know exactly what you mean, but I don't have any magic move to make opening the meter any easier.
What I've done in the past was to open it only slightly from the lower end (i.e. the end where the fuse door is), enough so that the back half of the case has a chance to be moved in the direction of the upper end of the case (i.e. where those pesky clips are located).
And I say "has a chance" because it doesn't really move in that direction, but you can at least try to then wiggle that back half of the case, all that while trying to lift it from the front half.
Sorry, this is the best "advice" I can give.
In most of the cases, with persistence (and some swearing), I was able to open these meter cases.
I think only once it happened that one of the clips broke for one meter, but the rest were fine.

I hope this helps!

[CatalinaWOW]

If you know exactly where the snap mechanism is you can drill a small hole and push the snap back with an appropriate diameter pin punch.  This leaves a hole in the case, but that is usually less cosmetically damaging than the pry marks from forcing the mechanism.  I am not familiar with this particular case so don't know if it is water resistant/waterproof which will obviously be compromised by this method.  If important a bit of RTV can plug the hole.

Unfortunately some snap mechanisms have a "keeper" behind the snap which is easy to break while forcing the snap back.  I know of no cure for this other than care.

[hirada]

Thanks very much. I've gotten well up to the swearing part so far. Now I am afraid it is time to move on to the patience part. It is exactly that it is not moving in any direction (asides upwards on the lower end) what made me ask
I wonder, what magical tricks the guys at gossen may have.

I'll keep on wiggling.

[AVGresponding]

I've gotten well up to the swearing part so far.

You might try using a spudger of some sort, you usually get plastic ones in phone screen repair kits, and can buy a metal one like BigCliveDotCom uses here: https://www.ebay.co.uk/itm/224064535197



It's an Italian company, so you can likely find an EU mainland seller for the bay of evil.

[hirada]

I have found those within eu borders without any problems. But before spending money, I'll give my thickness gauges a try. Rust permitting and If I ever remember, where I've put them last. Did not think about those at all. Great idea, thanks!

[giosif]

Now you've piqued our interest: why do you need to open the meter in the first place?
Care to share your "journey", in case this is a repair? 

[armandine2]

perhaps Dave has covered this in the EEVblog #46?

[Stray Electron]

I've gotten well up to the swearing part so far.

You might try using a spudger of some sort, you usually get plastic ones in phone screen repair kits, and can buy a metal one like BigCliveDotCom uses here: https://www.ebay.co.uk/itm/224064535197



It's an Italian company, so you can likely find an EU mainland seller for the bay of evil.

   You might try some of the plastic tools that are designed for removing automobile trim without damaging it. They're inexpensive and are readily available at Harbor Freight, Amazon and many tool stores.

[jpanhalt]

Tools for auto interiors are often relatively thick and designed for popping the Christmas tree attachments.

I use a guitar pick that the local shop gave me.  They come in different harnesses, mine is hard.  It fits nicely into the hairline crack and gets it wide enough to go bigger, if necessary.  Rarely will it damage either part of the case.

[Mechatrommer]

do as giosif's maneuver, ie open up the bottom first, and then at the top, slide in a flat thin object and lift up the top cover, it will pop open, i used paper knife without its holder to do the job (see attached picture, edited from dave's video), a flat screwdriver or the hp repair plastic tools may do the job as well i guess... ps: but dont lift up too far when its open, do it slowly as there are 2 wires connecting from pcb to the back of the cover for the who-knows-what jack hole up there... edit: 2nd attachment (the clips)

[hirada]

perhaps Dave has covered this in the EEVblog #46?

No, he does not. The best Video I have found so far is this:

[youtube][/youtube]

Which basically should have you set anyway, but I've tried and my plastic made frightening crackling noises, so I wondered, wether there is a more elegant version.

Now you've piqued our interest: why do you need to open the meter in the first place?

You'd be disappointed. I am heavily challenged to actually use a multimeter, I'd never even think of repairing one. Just some visual inspection I intend. 

I use a guitar pick that the local shop gave me

That is an excellent idea as well, as a former bass player I should have some flying around. Somewhere, that is.

My device, when bought used, had a sticker across the lower and upper half gap (no photo made unfortunately) that advised against levering (with a screwdriver). Hence this thread. I was wondering, wether the two front holes in the batterie compartment might have anything to do with it.

But the punchline I'll take away, you have to lever out the front part some way, there is no trick in releasing the snap mechanism in a friedly way. 

Thanks again to all of you!

[RobinLox]

Here is a nice way to open them: You remove the 4 torx screws. Then you pry the bottom oben with your fingers or a soft piece of plastic.

Now comes the tricky part: Hold the meter with the socket pointing downwards, pry on the gap around the middle of the meter and then smack the rear piece on the table a few times. If done right the upper half "jumps" out of the clamp thingies and the meter is open.

Be careful though: There is a short piece of wire where the power supply socket is connected.