Anyone know electronics repair at all?

I've got this project I've been meaning to tackle and wondered if anyone has any input. I have this old cheapo Memorex ipod dock, the iTrek, which is completely unsupported with no parts available anymore, and the AC adapter prong long ago snapped off inside the thing:

http://i299.photobucket.com/albums/m...dusu/iTrek.jpg

Battery power worked, like, once and never again, plus the batteries were a pain to get out (extraction involved a wire hanger), so that's not an option. I managed to get the prong shards out of the DC-in, and now I'm thinking about stripping the wires and attaching them directly to get power to it, but I'm not sure how to proceed:

http://i299.photobucket.com/albums/m...su/iTrekin.jpg

The black box with the white wires coiling around is the DC-in. I'm guessing the two strands of the power cord need to keep separated, so jamming them in the 2mm hole is probably not an option*. Could I attach them each to one of the rightmost solder points on the underside of the board? If so, how do I isolate which is which, or does it matter? Would getting it backwards fry the thing? As an aside, I lack the means to solder, so this will probably be an electrical tape and/or contact cement operation.

*It occurs to me that if the center prong in the DC-in is the positive terminal and there's a contact for the negative terminal on the inner wall of the DC-in, maybe I could establish isolated contact by stripping only one side of each wire. Could that actually work? Most likely the black wire would correspond to the prong and the striped one to the wall, right?

I will try to take sufficient precautions to avoid Darwining myself :panic:

Could this guy serve as one of my contacts:

http://i299.photobucket.com/albums/m...rekcontact.jpg

When the board is seated, it would normally make contact with one of the battery terminals (also circled). Just need to figure out which wire should make that contact, and where to put the other one.

It's a shame you don't live next door as I could do this for you. Ive done several laptop power socket replacements. The trick is finding which solder joints on the the underside of the powerboard are the + & - power rails. It really needs to be a solder job and not glue.

I couldn't really make much sense out of your pictures and your explanation, but I'm sure that without soldering tools, this won't work at all. The original board sort looks like it was machine soldered (very fast and precise) and you want to do it with glue :P

Yeah you definitely need a soldering gun. If you get the correct connections, it shouldn't be too hard.
But you WILL need a soldering gun, and solder. You can get them from really any kind of electronics
store. There are also DC cable heads you can buy that you could use to repair the old connection
system. I would try that.

Hope this helps
~Wes

Lol, okay I got the circuit mapped out as I was making this post, and I was making this way too hard. Ignore the blue cord coming in. White is an existing wire, but it's actually black so it doesn't show in the pic:
http://i299.photobucket.com/albums/m...iTrekinout.jpg

So all I have to do is like so:
http://i299.photobucket.com/albums/m...Treksplice.jpg

An underwriter's not and some tape, and that's a circuit, yes/no? Black wire is positive, white striped is negative, right?

Quote:

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Originally Posted by Taosaur

An underwriter's not and some tape, and that's a circuit, yes/no? Black wire is positive, white striped is negative, right?

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Sorry thats going to fall apart in about two seconds. You can twist it and use some wire crimps but a knot is not going to cut it.
Also, usually when you have a striped wire you use it for positive. not negative.

The knot is not what will secure the wire to the terminal: Learn How to Tie an Underwriter's Knot
With the cord entering through a small hole, the knot will prevent the internal wires from pulling taut at all. Looking at the terminal, I'm confident it can be wrapped and secured with electrical tape. I'd provide a clearer photo, but I only have my phone. As for the splice, it's a splice. Yes, solder would be more secure for the positive terminal, but I don't have solder right now.

You're right about the white-stripe wire, though.

Anyway, after I made this thread I realized my stepdad will likely be on Facebook this afternoon, if not at lunch, and he's been doing this stuff for 30-odd years, so I'll see what he says before I go ahead with it.

ETA: That first link is kind of crap--here's a better one: http://www.hope.edu/academic/enginee...b/Figures.html

Just buy a soldering iron. It's an extremely nice tool to have and it's going to help you a lot in the future too.

Quote:

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Originally Posted by Marvo

Just buy a soldering iron. It's an extremely nice tool to have and it's going to help you a lot in the future too.

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It's definitely on my wishlist, behind a voltmeter, which I could have used about three times in the past two days (including this project), but it's not in the budget right now. I'm currently in the employ of Mr. Obama and the state of Ohio, i.e. on unemployment, hence the interest in resuscitating items already in my possession. Really I've just been on a project spree, though. For instance:

http://i299.photobucket.com/albums/m...u/DSC02155.jpg

The past week or so I: 1) suspended the surge protector behind the desk 2) rendered the desk sit/stand convertible (standing now, takes about a minute to switch) 3) went through four or five tower placement strategies in the midst of #2 and 4) putting up the bike rack, which didn't go exactly as planned, but works and it's kind of cool that it's coming right at me :panic:

http://i299.photobucket.com/albums/m...su/Camgram.jpg

I was also ready to open up my long-defunct digital camera before I figured out that my tools were insufficient and Canon may well fix it for free (that guy's a saint, btw).

I also did this:
http://i299.photobucket.com/albums/m...zzlePagoda.jpg

And as you can tell, I've been photo-documenting everything :D

Oh, and you know, resumes and interviews (well, interview) and shit.

You should make a thread in the Artists corner or somewhere, showing all the stuff you're building. That's awesome. Sucks you can't get a voltmeter/soldering iron though, those are awesome tools :)

My only concern for checking the circuit here is that the thing stopped working on battery power, which suggests a break in the line somewhere. Hopefully it's not near the DC jack, and everything does look pretty snug and secure there. Also, no soldering is not a big concern here--I want to bypass the DC jack, and there's a bypass already in place. Why wouldn't I use it? If I had a soldering iron, I'd still be splicing the negative and attaching the positive at the same place, and that little metal piece really lends itself well to wrapping and cinching the wire in there. It's also pretty accessible to go back and reinforce later if I get a chance.

And done:
http://i299.photobucket.com/albums/m...rekspliced.jpg
http://i299.photobucket.com/albums/m.../iTrekdone.jpg

Hah, nice. I was going to ask if you'd consider replacing the broken jack-in. I don't suppose you have any surplus electronic stores around?
Anyways..

I did look into getting a new cord a few months back, but Memorex has disavowed all knowledge of this product's existence and replacement parts are not to be had, short of buying a whole unit on ebay. It was a weird, tiny, flimsy prong, anyway, and a splice outside the case would have been the worst possible solution. Given that battery power stopped working years ago, there's no advantage to having it jack-in rather than hardwired. What I did is actually a much stronger splice than if I'd soldered the wires to the board without the underwriters' knot--it'll shear off at the casing before either of the wires inside come loose. Thank you, eighth-grade shop teacher :cheeky: