/diy/ - Do It Yourself

Wow, so many grammatical errors in that post...

For a bit more information, it says it draws 0.3A @ 120VAC and 60 Hz. Also, on the other side of the little black part with two screws, the cord terminates into three comparatively thin wires.

>>708600
Before I throw anything away that is electrically unsafe I cut the power chord off to let people know it is dangerous to plug in. The fact is that if something unsafe is discarded or given away, and the person who obtains the goods plugs it in and kills or injusres themselves or others, then the person who discarded it is liable for negligent behaviour. I would take it as a warning that the goods are electrically unsafe

>>708606
Or maybe just someone wanted to have an extra plug+cord for whatever project.
>>708600

Hmm anon first thin i suggest you to do is shortcircuiting the wires of the cord, so whatever is charged there would discharge.
then take away the black cover of the cord, strip the wires and do the same with another triplet of wires, don't fuck up with the colours. then insulate them with insulating tape. If you are worried that it might explode or something you can wire it something you can use to control it from distance, like a relay, your house's thermal switches or whatever. 0.3A is very low so a shitty relay would be enough.
I hope you can understand my shitty englisc.

>>708606
I do this too. It's common sense I think. Not ever from a liability standpoint. It's like putting up a warning sign.

>>708606
You're not liable. The simple fact that it's discarded is sufficient to warn a reasonable person that the device may not work safely.

You are, however, liable in most places for leaving "attractive nuisances" lying about, because people can't control their kids. If you leave a fridge on the street with the door on, or have in your back yard a swimming pool that's unsafe for children, or a lion in an enclosure that someone can break into, that's an "attractive nuisance" and you can be held liable for accidents that happen to wilful trespassers doing stupid things.

This only applies to children, though. No-one is reasonably expected to forsee that a child would uplift an electrical device, and take it home, and plug it in, and no-one has a duty of care to protect adults from their trash.

>>708600
Don't worry OP. Very high chance that it was just a scrapper that cut the cord. I have reattached cords to many things and they always seem to be in working condition.

As for capacitors and stuff, just be careful around the crt. Everything else isn't of that much concern. Discharge the psu caps with a screwdriver if you feel you must.

Attaching the cord shouldn't be too bad. I solder gun would be of use, but a soldering iron should do it. The cord may even be easily accessible via those two screws.

>>708600
People cut cords off old stuff because they are frayed and dangerous.

>>708606
>>708655
>>708715
Really? Every device I see without a cord is a result of copper scrappers coming along and cutting the cords off (which is endemic here in Australia, its a common complaint on hacker space mailing lists that its annoying to have to re-cord every device we get out hands on). You see them out in force during cleanup, pulling MOT's, CRT yokes and cutting power cords.

As far as liability, as soon as you put the device on the curb it becomes council property. I literally had someone try to get me charged with theft because I was lifting shit from their pile (a fuckload of CB and other RF equipment).. Cops came, told them it was no longer their property as they had placed it on the council verge, and smugly suggested I call the council to "check with the owners of the refuse if you are allowed to remove items". At this point the dude started hauling crap back inside, I just came back later on the night before pick up and had my way.

>>708804
People are not that smart. People go "hey its broken", and throw it out.

>>708600

I've seen people cut cords off appliances that people have put out at the curb just for the copper.

Thread reminds me of something my neighbour did.
>Get new vacuum cleaner
>Does a very good job despite being cheap as fuck
>One day it doesn't work
>"Oh well, I'll just trash it and keep the long ass cord in case I need it"
>Proceeds to pull out the cord from the vacuum (it had a cable coil) and cuts it off at the very start to maximize cable lenght
>Rolls up the cable and just as he gets the plug in his hand realizes it was unplugged the entire time

jesus fucking christ, how about opening the goddamn thing up and inspecting it instead of arguing whether or not its unsafe

Sorry for just disappearing...

Well, I'm certainly conflicted, now.

>>708606
>>708655
>>708804
Are what I was worrying about, that somebody cut the cord as a warning.

But, I really want a monochrome computer monitor...

I've yet to disassemble it, but photos on the internet seem to suggest that the circuitry isn't incredibly complicated. Hopefully, if it's a death-trap, there might be a giveaway inside.

I got it at a thrift store, along with the computer, a disk drive, and a box of software and manuals. They were together. They actually taped it all together...

The computer works just fine, powers on and outputs video. The disk drive also powers on without incident. My point is, this monitor seems to have come from somebody's setup. So, it clearly wasn't just trash on the side of the road.

As for other reasons for cord mutilation...

* 'somebody wanted a spare cord for a project'; that's depressing, and I'd like to believe nobody would do that to vintage computer hardware... but then I remember that, to most people, this hardware is less useful than a discarded blender.

* copper scrapping; that'd be my first assumption if I got off the street. I'm just not sure how that would happen to a monitor that ends up at a thrift store. I guess:
> prior owner leaves everything on curb
> scrapper comes along, cuts of the easily accessible, obvious monitor cord, continues on his way
> prior owner realizes nobody's going to take it away/somebody desperate for money grabs the lot
> ends up at thrift store
> ends up here.
Not completely unreasonable.

>>708940
Oops. He should have called tech support.
>Have you tried unplugging it and plugging it back in?

>>708942
That is an excellent point, and is my next course of action.

I didn't do that to start with because I posted this thread shortly before I went to bed. It appears I gave far too much weight to the "this is a slow board" part.

Either way, I figured it would be worth spending a couple of minutes posting a thread if there was a chance of somebody noticing something painfully obvious, pointing it out, and saving me unnecessary grief.

If, like, somebody were to outline their plans to repair a typewriter and they mention "and I'll use hydrochloric acid to clean the metal parts", a single person could save them a lot of grief. But, nobody has said 'hey, dumbass, this is obviously a horrible idea, don't attempt repair, don't open it, don't even touch it', and the people here seem smart.

This makes me far less nervous, and that makes me less likely to screw up.

Photos should be forthcoming.

cord cutting is the age old sign for electrical fault.

back when I worked in an electrical store we used to cut the cords off when there was an electrical fault before we put shit out back for collection. it's a liability thing. if someone steals shit from your rubish bin they can theoretically sue you for getting injured in the process.

Holy fuck I hate this so much. Here's the literal first impression...

>>708965
Come to think of it, I'm not sure what would constitute an electrical fault in a monochrome monitor. Apart from something general, like a damaged power supply.

The thrift shop label mentioned "needs power cable" (hah), so they couldn't have been limiting liability. The owner may have, but I have no idea about the owner.

>>708979
Wow. First, this camera can see so much better than I can. Not sure how to feel about that. Second, those are some seriously dusty knobs.

I... guess I'll post some closeups and keep talking to myself. In the mean time, if anybody has any observations, I'm all ears.

Here's the board to which the cord connects. Nothing screams 'damaged' to me.

>>709001
And the other side. No charred solder joints or anything...

>>709005
how to i foto

Here's the transformer. Not much to look at. How the hell do you know if a transformer is bad?

I used a screwdriver to bridge the contacts of the electrolytic at the top of the 'mains-in' board. I didn't die. It didn't even spark! So, uh, that's a good thing.

...

That's not even one of the capacitors you really need to worry about when screwing with a CRT, is it?

Also, I just fully realized; these monitors tended to use various toxic substances, beyond lead or mercury, didn't they? So, that's a fun thing, too.

...I don't really know how to safely handle a CRT.

Alright, I won't ask to be spoonfed information readily available with the slightest amount of effort, but I will ask one thing;

are there any major differences (as far as safe handling practices) between a typical CRT TV and a monochrome computer monitor?

Anything liable to zap you that exists in monochrome monitors but not TV's, or vice versa?

Nigga the cord is just cut because someone wanted the cord for scrap.
They didnt take the monitor because it doesnt pay shit and most places dont want them
Put a new plug on it and plug the fucker in

>>709038
If it's not been plugged in in weeks, you don't have to worry about any capacitors.

>>708979
crt monitors make scary sparks and noises when they blow. this is enough to deter a sensible person from using them again. really weird that it doesnt have an IEC plug though.

just apply power and see what happens. if it doesnt turn on or makes a sound then turn it off.

use extension cord and turn it on from across the room incase something blows. I play with mains voltage all the time. its no problem. just dont touch it while its on. disconnect power from the wall before approaching it.

>>709039
that giant nipple will definitely zap you with thousands of volts. do not touch it while its on. serious death potential.

>>708600
Scrap cooper fluctuates between 2 and 4 €/kg where I live.
It's funny to watch how streetlights stop working when prices rise.
Thing is, idiots take the cooper from electronics and trash the more valuable components.
Fucking gypsies.

>>709058
This guy is a moron.
Don't touch the fucking base of the screen unless you know what you're doing.

>>709049
That is a wonderful way to think. I would do exactly that, if I weren't so paranoid and cowardly.

>>709058
The sticker says that the store got it in on the fifth, and I doubt somebody just unplugged their computer, chopped off the monitor's power cord, boxed it up, and gave it away. It's /probably/ been years without power. "Probably."

>>709070
Yeah, I'm kinda hating the manufacturer for using an attached cord.

What does "apply power" entail? Chopping up a mains cord and just splicing it onto the wires sounds like an amazingly bad idea.

How about attaching the wires to an IEC socket? It would be a waste of time and socket it the monitor is dead, but it's the cleanest way I could think off...

Also, I suppose that, thinking rationally, any decent extension cord should be able to handle pretty much any electrical fault condition with, at worst, tripping the breaker. Right? I don't care too much if I break the monitor. I mean, getting sprayed with capacitor electrolyte doesn't sound particularly enjoyable, but that's why you keep your distance at first power-up.

Basically, if I can be decently sure that I'm not going to start a fire, I'm happy. And I have a cement back porch, so that would mitigate any damage occurring at the monitor's end...

>>709071
I am familiar enough with CRT's to know this much. That isn't a concern at the moment, as it can't *be* turned on.

>>709073
Gotta love it.
>You think this'd be worth anything?
>A piece of plastic? Nobody needs a piece of plastic! Now shut up and carry this piece of copper.
>they take the laptop's charger; laptop is unharmed.

Anyway, for the moment...

I connected an alligator clip between a screwdriver and the formed metal across the top of the case. I then used the screwdriver to contact the metal clip underneath the 'nipple'. No sparks, no noise, nothing. I'm taking that as a small positive sign.

Although, I am slightly worried, did I scratch the 'aquadag'? IS that stuff easily scratched? I can't see directly under the plug to be able to tell.

Also, the connection to the HV wire seems to be very slightly looser. It may have just been crusted on with dirt, though.

>>709075
What do you mean by the 'base of the screen'? Are you talking about the circuit boards at the bottom?

Shit. I just realized, this was a polarized plug/circuit and I have no idea which is which. I'm sure I could tell which wire is ground, but I don't know how to tell which is hot and which is neutral.

>>709117

If you can remember how it was, the neutral would have a ridge along the outer jacket.

>>709118
Remember how what was? Just to be clear, I got the monitor after the cord was cut off.

If you were talking about something else, disregard that, I'm too tired to brain well right now.

>>709119

Right. I was assuming that picture is yours. On that tiny bit of cord left, one side of it will have a ridge to identify the neutral.

>>709119
Wait. Are you talking about the little bit of cord left at the end? If so, I'm in luck; I haven't cut it off from the wires, yet.

>>709121
Alright, that makes it easier. Thanks! I never would have known about that...

Now, as may be obvious, I need some sleep. Night, /diy/, and thanks!

>>709038

The most dangerous components in a CRT power system are the large capacitors (like the big blue cylinders in your photo that say 3300uf 35V) and the flyback transformer, if it has one.

http://en.wikipedia.org/wiki/Flyback_transformer

These components can hold a charge for a week or two. If they haven't been plugged in for months or years there is very little chance of any shock.

Here's everything you ever wanted to know about your thing:

ftp://ftp.apple.asimov.net/pub/apple_II/documentation/hardware/misc/sams/Sams%20Apple%20II%20Monitor%20A2M2010.pdf

>>709117
Black is hot
White is neutral
Green is ground
Learn your colors.

Also since you're already hacking it up, you could put a standard C14 plug on there from an old power supply for more flexibility. To test it you could put wire nuts on it and it'll work just fine. Not ideal for a permanent solution but way quicker than soldering it just for a test.

Also fuck scrappers. A few years ago I was going to pull a fairly large CRT out of someone's trash (maybe 19" or so?) and some asshole had cut the VGA cable off.

> Chopping up a mains cord and just splicing it onto the wires sounds like an amazingly bad idea.

nonsense. if you do it properly, using solder and heat shrink, it will be as safe as new.

> are there any major differences (as far as safe handling practices) between a typical CRT TV and a monochrome computer monitor?

your monitor uses a heavy power transformer so the main circuitry runs at low-voltage DC. many old TVs worked directly off of the 120V line, so are considered "hot" and dangerous. they do this to save money and make it lighter.

>>709220
I figured it would be a good idea to stay away from the capacitors.

There's a little 'can' off to the side of the monitor, separated by from the rest of the board by insulating walls. The HV cable connected to the tube connects to this device, so I'd imagine this is the flyback transformer. Even if it isn't, it's /something/ that generates HV.

>Here's everything you ever wanted to know about your thing:

Ho-ree fugg. Wow. How do you learn where to find these things? Apart from collectors and sellers, I could barely even find acknowledgement that this monitor exists.

>>709237
I figured there would be *some* color scheme, but I was worried that it wouldn't necessarily be correct for all devices.

I didn't recognize the term 'wire nut', so I google'd it. Yeah, I know what that is. But, see below.

And yeah, I can definitely agree with that; fuck scrappers, seriously.

>>709258
I guess I don't want to splice a cord on directly because of the 'cutting open a power cord' part rather than the actual 'splice' part.

Any permanent fix will probably be done with an IEC connector. I like IEC connectors. They're always there for me.

I might go with suggestion to use wire nuts for quick testing, though. Any particular way to safely prepare a power cord for splicing, or do I just start cutting into it?

Also,
>so the main circuitry runs at low-voltage DC
actually makes me feel much better. I hadn't thought about that.

Hah, one of the first results when you search for 'IEC connector' shows an image of a part with two screws on either side which looks like it would fit the hole perfectly. That's awfully convenient.

Just a lurker here: Is it safe and possible to discharge any components by touching them with a cord with only the ground wires connected. The 2 live wires are not connected (AC).

>>709310
One thing you should note; ground is supposed to be connected to ground, right? A proper, earthed connection. That's good. Keeps you grounded (hah).

And normally, the ground connections *are* actually grounds. Sometimes, though, the electrician doesn't do what they're supposed to do. In a house with particularly horrible wiring, 'ground' may not be connected to a proper ground.

I seem to recall a few stories of ground being connected to neutral. Less spectacularly, a ground might be connected to something with a nonzero electrical potential with respect to earth.

Of course, if you know that you have good wiring, this isn't a concern

>>709313
Please don't talk about mains power again.

>>709313
OK thx for the info.

>>709316
Okay. Why?

Also, why is that cat not freaking out?

>>709316
>internet exploder
pls no

>>709296
well obviously they found it cheaper to ditch the iec plug and just use a cable gland. just remove the cable gland, chop up an extention cord, use screw terminals to connect the chopped extension cord to the power lead.

>>709323
I guess so.

I'd never heard 'cable gland' before, but from Wikipedia, you just mean the plastic fitting which is screwed on and protects the cable?

The remaining bit of power cord looks like it would be a pain to work with, wouldn't it work just as well to connect to the individual wires on the other side of the connector?

Finally, is there any difference between using screw terminals vs. twist-on wire connectors?

(Christ I ask too many questions.)

>>709310
No, because capacitors hold a potential difference *across* their terminals, not between their terminals and ground.

If you touch just one terminal to ground, it will do nothing, as there is no path to the other terminal.

If you touch both terminals at once, you'll short them, and if it's a large capacitor, something will explode.

To discharge a capacitor, you bridge the terminals with a resistor, ideally several watts and several megaohms. While you can discharge a capacitor by shorting it, the arc will vaporise a tiny bit of metal every time you do.

>>709333
Screw terminals need a screwdriver to go on, wire nuts don't.

Screw terminals need a screwdriver to come off, wire nuts don't.

>>709338
...yeah, that was a pretty stupid question.

>>709333
i have never used twist nuts. i dont know how well they work with stranded cable. appliances usually use stranded cable. extension cords usually use stranded cable. I think wirenuts are only for solid cable.

>>709349
Ah, good point. I know I've /seen/ them used for stranded cable, but that doesn't mean it's a good idea.

Wikipedia has this photo, but, you know, Wikipedia lol. And the article doesn't say anything about stranded vs. solid conductors.

>>709349

They're fine for stranded. Something to be aware of is that wire nuts vary greatly in quality. The best general use ones I have found are ideal can-twist.

>>709357
I'm in the US, and it doesn't look like any local store carry that brand. I won't be using wire nuts for very long, but still.

>>709352
Oh. That's not stranded wire, anyway. Disregard...

>>709349
Just put the fucking IEC connector on it already. You are over thinking it. Order from digikey and you will get it tomorrow.

>>709020
>How the hell do you know if a transformer is bad?

>>709070
The weirdest part is that it has a footprint for an IEC socket but they cheaped out and went for a single cord.

>>709367
This. Order a male IEC and some 8ish mm heat shrink. You'll also need some ring terminals and some lock and spring washers (automotive or hardware stores will have these) and some green AC rated wire (cut up another 3 core AC cord if you need to) See that red arrow? It's pointing to nut that is holding that transformer into the chassis. You'll need this hardware big enough to fit over the screw/screw post that nut sits on (most likely M4, but worth checking.. take the nut to the hardware store with you). You will be placing this hardware under that nut.

> One by one, pull the existing strands out of the remaining cable segment in the chassis.
> Remove old cable retainer
> Strip existing active neutral and earth, tin ends.
> Test fit IEC to the hole in the chassis, file the hole bigger/re-drill screw holes as required.
> Cut about 10mm of heat shrink, slip over existing tinned wires.
> Feed cables through IEC cutout in chassis, solder to IEC socket, fit and shrink the heat shrink.
> Solder a ring connector to the existing earth wire, fit and shrink the heat shrink.
> Cut about 6cm of green wire, strip, tin solder to a ring connector. Cut and fit some heat shrink, also cut a second piece and feed it on but do not shrink it yet.
> Solder new earth wire to IEC, shrink second piece of heat shrink over connection.
> Remove transformer nut, place a lock washer, then the ring connectors, then a lock washer, replace and tighten nut.
> Screw in IEC, enjoy your likely fault free display.

It must be said in a display that old there may be some dry caps that will fuck with your day, but cross that bridge when you come to it. Get it powered up (its not going to kill you, it has a fuse) and see what it does first.

>>709367
Fuck it, you're right.

Something like this, right? http://www.digikey.com/product-detail/en/703W-00%2F04/Q212-ND/

I measured the distance the between screw hole centers on the monitor--about 4 cm. This connector and several others list 40 mm for this distance, so I assume this form factor is somewhat standardized.

What's "Quick Connect"? Am I supposed to crimp the wires to connectors? Or is it okay to just solder the wires on directly?

>>709372
I knew this was coming. I was starting to get disappointed.

>>709382
>>709383
Why do I ever post before hitting Update?

>tfw anon writes out a full tutorial, including photos, for you

T-thanks...

>>709384
>Why do I ever post before hitting Update?
I know right, or I would have added..

> mfw from this day forth I will stencil this onto every transformer in every device I sell.

..to the end of my post. Top jej.

> T-thanks...
Pay it forward.

>>709382
Okay, time for a few more awful questions. Mostly arising my from poor understanding of AC terminology/slight differences in use.

>Strip existing active neutral and earth, tin ends.
This means three wires--active; neutral; and earth;--right?

And earth is what's connected to the round 'ground' pin?
And the black wire is 'active' or 'hot', and the white wire is 'neutral'?

>Feed cables through IEC cutout in chassis, solder to IEC socket, fit and shrink the heat shrink.
At this point, I should only connect the black and white wires to the socket, right?

Alright, do I have this correct? It should be:
* black wire to active/hot on the IEC socket
* white wire to neutral on the IEC
* green wire to transformer, to new green wire, to ground on the IEC.

Finally, should http://www.digikey.com/product-detail/en/703W-00%2F02/Q210-ND/245551 be perfect for the job?

I swear I'm all done asking questions.

Alright, I think I know what I'm doing. Or, at least, /what to do/.

I'mma a let this thread die, now. When I have some result, I'll post a followup. Thanks, /diy/. Without your help, I probably would've just electrocuted myself and given up, or would've been too uncertain to even try anything in the first place.

<3

>>709392
>http://www.digikey.com/product-detail/en/703W-00%2F02/Q210-ND/245551
yes
commonly refered to as a "kettle plug" because they're a standard fitting on electrical appliances like kettles.

>>709310
always use a resistor inline, otherwise you might blow the equipment, also what the other guy said about caps.

>>709320
I thought you were talking about neutral being bonded to ground at the meter, not in an appliance. In an appliance, yeah I can see that being bad.

>>709020
Use an ohm meter. If you get any continuity from one side to the other, it's bad.

>>709463
which part of either side? just continuity between ANY two connections on either side?

>>709471
you need to start googling friend. "testing a transformer" would be a good start, as would a look at the wiki page so you understand how they work, and how to readily identify primary and secondary coils.