Neck Ache: Part 3

With the bottom cable all soldered up It's time to move on to the top half. Instead of soldering the top half, I gambled and decided to just replace the pins. The gamble was that even though they're the same size, the pins on the iMac's cable might pull out easily if the little plastic keepers don't go all the way back down.

So I just grabbed my handy x-acto knife and carefully pried the little keeper bits up the smallest amount possible to release the wires. Once I had them all out, I consulted my pinout (see bottom) and started plugging the iMac's wires in. Because of that pesky extra green wire, I stole the green wire from above and soldered it to the green cat 5 wire I ran so it would fit into the adapter.

It actually took me a really long time to get all those tiny little wires pushed into the plastic thingy. But I eventually got it.

Like i feared, many of these wires aren't really in there all that well and tend to want to slip out with relative ease. I'm not 100% sure how to remedy this issue. I thought about hot-gluing where the wires go in but I'm paranoid about melting any insolation or screwing anything up like that. For the time being, I just flattened out the wires and wrapped them in electrical tape.

Once the video cable was all finished, I moved on to the backlight wires. For these, I'm using the cables Apple allocated for the Inverter to run the two pairs of backlight wires. I started by cutting back the heat-shrink on the backlight power cables.

Incase you haven't noticed, I have a lot of... lets say, "special" moments. I get it into my head that I know what I'm doing and got it all figured out, and then, do something really stupid. Like cut off the the end of that video cable! grrr... Anyway, in this installment of "Dave's Super Special Moments", (most likely brought to you by leaded solder), instead of cutting off end so I have the connector part to solder onto the bottom, I just pulled off the plastic part as I've been doing and soldered the the plug ends right to the inverter cable, or rather, the cable that plugs into the inverter cable:

This is the cable that connected the original inverter to the inverter cable right behind the display.

Anyway, so that was dumb. Luckily, since I just happened to have some spare monitor parts lying around (weird, right?) so I was able to solder on the end from that:

So, that's it. Everything was ready for the big test. As of that moment, I was 50/50 with this monitor stuff working. After I got everything hooked up and turned the monitor on... it didn't work. Now at this point a familiar feeling of dread passed over me, but I was able to shake it off and go right into troubleshooting mode.

Symptoms: The backlights turned on for a second, then turned back off. The picture on the screen was present even after the backlights turned off and was very fuzzy.

Testing: I grabbed my multi-meter and began testing to make sure all the wires were still connected and no exposed wire bits were hitting any other wires. I did the continuity test on the inverter wires first, and they all checked out. I then moved onto the video cable.

I made sure each of the wires was where is was supposed to be based on my pinout. All good. Then I did a continuity test from the black connector that plugs into the video card to the plastic thingy (above) that plugs into the back of the LCD, making sure that there were no broken solder points. I also wanted to make sure there were no exposed wires touching other wires, so while I had one end of the multimeter on a wire in the black connector, I slid the other lead of the multimeter across all of the gold ends on the plastic thingy and made sure it only beeped when touching the right pin. A lengthy explanation for a lengthy process.

Anyway, after doing all this, I found that a single wire had managed to go and get broken.

That's right, that little bastard, RIGHT THERE, ruined my entire day! To add insult to injury, it was one of those hair-thin stupid wires that was a pain the butt to strip and solder the first time when it wasn't surrounded by a heaping glom of un-shrumk heat-shrink tubing. Yuck.

At this point I grabbed some cookie dough out of the refrigerator and called it a day. I REALY hope that is the culprit and I'll have the monitor fully functional by the end of the weekend. We'll see.

Oh, here's that pinout I promised:

I know it's messy, but it I understand it and that's all that really counts.

Neck Ache: Part 2: Soldering

My shrink tubing isn't shrinking all that much when I put it next to a soldering iron. Any ideas?

I was very sad when I shattered the first new $100 LCD panel I got, but that was about it. Right now, I am in a fit of rage over my stupidity in cutting off that flipping cable end. I spent well over two hours today stripping and soldering wires, many of which were no thicker than my hair. I'm not sure which hurts worse, my back, my neck, or my fingers... Anyway lets take a trip back in time and try to figure out how I got here:

These are the devil's wires. They're ones in the black cable. They are so thin, if you showed them to a MacBook Air, it would probably have a kernel Panic on the spot. That's a terrible mac joke, but these cables have damaged my mental stability! Sorry. I found the best way to strip these super slim wires was to take my x-acto knife and lightly cut through the insolation all the way around and pull it off. I should say, even after discovering this trick, I was still less than 50/50 at not just breaking the wire. It sucked. But you wont have to worry about this, because you didn't cut the cable.

The wires in the grey cable are still thin, but soooooooo much easier to work with. Though they are too small for the 20-22 AWG hole on my wire strippers, I found that using the area just below that to lock onto the insolation worked out great. Just don't squeeze the handles together too hard or you might cut the wire.

I used the same trick on the wires that attached to the LCD's video card

Oh forgot to mention, I wen't out and grabbed one of these puppies for $10 earlier today and it saved by butt! They are super great, free up your hands, and you should get one if you don't have one.

When I was at QCM inc. (the cable making place), they nice guy there demonstrated how to properly solder connections such as these. First you get your wires situated right up next to each other as shown below. If, like in this case, they're stranded wires, inter-tangle the wires a little. Then, take you hot soldering gun and melt some solder onto the tip. Then, in a single motion, bring the tip down onto the overlap between the two wires, lay the melted solder along the strands, and pull it back up.

22 wires doesn't sound like a lot. But it is. Anyway, I'm completely burnt out on this soldering business for tonight. The top is just going to have to wait.

Neck Ache: Part 1

When I stopped by the cable company QCM inc. and talked with one one of their very nice employees. Long story short, it was going to cost at least $100 for them to do it. However, due to the non-ribbon style cable that came in my new, new monitor, he said it should be easy enough to solder it myself and save myself the money. However, he was kind enough to demonstrate the proper technique and leave me with a bag of pre-cut shrink tubing.

With my knew knowledge, I sat down to make it all happen this morning. Five or so hours later, I've learned a lot, but haven't gotten very far.

I started out by dissecting the video cable that runs through the neck and discovered a few things about it. First off, taking the insulation off of the grey cable, there are 4 wire groups. Each group has 2 wires and one hidden wire: 2 hair thin wires and the shielding around these is the third.

As you can see, these wires all have golden ends. This is because I used an x-acto knife and pried up the little tabs on the on the plastic connector and gently pulled them out intact. This is a very smart thing to do.

Unfortunately I only had the brilliant insight to do this on the top. On the cable coming out the bottom, I cut it before having time to think about it. Please, this is a public service announcement: DON'T CUT THE EFFING CABLE!!! Sorry. I don't like when people use all caps, but seriously, this is important and I am very sorry that I cut the cable. Anyway, yes, if you don't cut the cable, use a small flathead screwdriver to peel back the steel cover.

You will then clearly see it's just another plastic connector with the little gold pins in it. Like before, grab the trusty x-acto knife and peel up those tabs. You'll be treated with this beautiful display of pretty gold bits!

Congratulations! You've just made your soldering life 400 billion trillion billion times easier! I on the other hand am going to suffer as a result of my incompetence. Aren't you glad I get to suffer for you? :)

Well now that that's done, we're still 1 wire short. The new, new monitor's cable requires 22 wires. The iMac's cable, despite the clever shielding trick, only has a total of 21 wires. So it's time to crack the neck and add a new cable. Heads up: this part sucked.

So I wrapped the neck up in an ethernet cable to ensure it didn't explode on me (Fun Fact: turns out they don't explode, they implode). Then using the fantastically made bits I had made, I unscrewed and removed the screws.

Now at this point, it's very important to know which way's up. I didn't know. Thus, as alluded to by my fun fact, it imploded. It wasn't really that bad, but it took blood, sweat, and tears (ok, not tears, but blood and sweat) to get it back. I didn't take any pictures of this due to extreme anger and frustration, but if this happens you to, find a small headed flathead screwdriver with a long, sturdy handle. Stick the blade of the driver into the hole on the back and use it as a lever to align the two holes. Make sure the two pieces click back into position, and you're good to go.

Ahem! So, when you remove the weird 3 pronged screws, underneath them, there are holes. Three of them have one hole. One of them has two. Make sure the one that has two holes is face up. That is the top. If you have it face down, you will have to go back and read the grey instructions above as to how to fix your imploded neck assembly. Two holes = face up.

Once it's all open, get comfy and begin attempting to thread your new wire. It's hard. I threaded a twisted pair of wires I scavenged from some spare ethernet cable I had laying around. The thinner the better, cuz it's a tight fit.

I started out by pushing the pair up through the bottom, and grabbing it with a pair of needle-nosed pliers and pulling them through. (again, sorry no pictures of this, I was still cooling off from my state of rage) That was pretty easy. Getting them through the top was a pain though.

First, unscrew the three screws.

Top View

Once the three screws are out, you can pull the end bit up, away from the neck to make it easier to thread the wires. (as much as I tried, I couldn't get it to actually come off, which is too bad because that would have made life easier, but oh well.) So take the new wires and push them down the hole where the other wires are going and pull them out with a pair of pliers.

Bottom View

Keeping the end bit separated from the neck as much as possible, bring the wire around and push it through the back. After trying a few (hundred) times, I finally got it. Pull the excess wire through and make sure it curls up nicely next to the other wires.

Then just snap the top bit back in place, re-screw the screws, put the neck back together and you're ready to get your solder on. However, I'm done for the day, but stay tuned for the exciting conclusion.

Keep in mind, this whole wire-threading process took me about an hour and a half. This thing it built to withstand a nuclear blast and there's not a lot of extra room. Good luck. 

Monitor Replacement: Renaissance

Today went very well. The new LCD Monitor came and when I opened the box I was surprised and very worried. It wasn't the same. HANNS•G model HW173A (old) vs. HB171B (new)

Ignoring the outer shell, the components themselves are quite different. The new boards are linked directly together instead of with a ribbon cable. The monitor controls use a 12 wire ribbon cable instead of the six used by the original which nixes my plan of using one of the iMac's Firewire ports as the outlet for that. The power supply is slightly longer where it meets the video card. And the cable connecting to the monitor is not the same ribbon cable.

However, it turns out all of this is either quite beneficial or easily gotten around. The longer board doesn't seem to pose any problems in terms of fitting into the dome, I should be able to get a simple cable extender for where the two boards connect, the controls ribbon cable... well that really does suck but I'll think of something, and finally, the cable connecting the video card to the monitor saves me a lot of work; it should be super easy to splice it into the iMac's cable that goes through the neck. Ohh and the new one has DVI too which I initially thought would make the card bulkier but doesn't and will provide me with better video quality.

After my epic failure with the last display, I was keen not to make the same mistakes twice. I did a little forensics work on the old panel and it seemed to me like the new panel (which is slightly larger than the old) cracked because of too much pressure along the edges from the metal surround holding it in place.

This is because the metal surround was made for the smaller screen and thus is ribbed to help hold it in place. When the ribs pressed up against the glass panel, they cracked it and coast me $100! Grrrrr

I also wanted to hedge my bets so I'm going to be sporting matching powder free latex gloves and anti-static wrist strap.

With this in mind, I got to work. The steps I went through are the same as in Monitor Replacement Part 1 and Monitor Replacement Part 2.  Here's where we left off:

With the new backlights in place, the newly dremeled black plastic surround is placed back onto the backlight assembly fallowed by the diffusion sheets from the new monitor.

I then placed the LCD panel on top of this and used electrical tape instead of the metal surround to secure it in place on 3 sides. And that's it. I screwed the whole assembly back into the iMac's front bezel and hooked it all up. I must say at this point I was honestly expecting it not to work. However....

IT WORKED!!! Please forgive the poor lighting and all but... it worked!

So tomorrow I'm going to bring the iMac's neck into a Cable company I found on the internet called QCM inc. and see if they'll fasten some connectors to the video cable so it'll easily connect to the monitor's video card. I'm super excited for all this!

Monitor Replacement Part 2

Spent $45 on the way home from school today to get a shiny new Dremel. I find it interesting that the cheapest Dremel you can buy (at Lowe's) is cordless. The cheapest corded versions started at $70. More powerful motors I guess...

Anyway, got back and took those tabs off in no time. (Don't judge, it's been a while since I've used a Dremel)

Now, there are more different tabs that need to be removed. When I put the diffusion screens from the new monitor onto the iMac's backlight assembly and tried to put the black plastic surround back on, I noticed these diffusers have tabs sticking out in places that the iMac's diffusers don't. I considered just using the iMac's diffusers but upon closer inspection, they one of the layers looked much different so I figure it's best to stick with what was made for the LCD matrix. So I just grabbed a pair of nice scissors and cut 'em right off clean and pretty like. And you're like, that's what she said!

Once everything was all happy with the diffusers, I decided to test-fit the LCD matrix. Too bad it was too big. And you're like... sorry, I'm very tired But seriously, the LCD matrix of the new display was a few millimeters bigger than the one that was installed in the iMac. To add insult to injury, the ribbon cables connecting the LCD matrix to its circuit board is a few millimeters shorter than the iMac's. Yuck. I'll save you the hours of thought process and trial and error that went into figuring this out and get right to it (lucky you!):

So you can't see it in this picture naturally so I've taken the liberty to draw on the track that the LCD matrix fits within. Now the bits on the left are what's in the way. There's stuff in the way on the top to but don't worry, we'll talk about that later. The track along the bottom is (I figure) critical for the LCD to rest on and along the right, the plastic is too thin and cutting the entire track would probably end up breaking it. So I used my Dremel to bring the track down to the surface level.

With the left side out of the way, we can tackle the next problem: the ribbon cables being too short. My solution for this was to completely cut the top of the black plastic surround. I was surprised it actually seemed to free up just enough room and at the same time, still managed to stay firmly connected to the assembly all by itself.

Things to note from the photo above:

1. When I cut the top off, I left the top corner intact. There is a tab/snap combo that is the key to the black plastic surround not needing any glue to stay on.
2. Taking the top off the black plastic surround left the aluminum from the backlight lamps exposed. I wasn't sure if that was a good thing or not, so I just covered it with a strip of electrical tape. This has the added benefit of covering and smoothing out my shoddy Dremel job of the tabs on the top at the beginning of this post. 

I test fit the panel and everything seemed to work out. I'm going to wait to install it completely until I can get my hands on some of the double sided tape that was originally used on the black plastic surround to keep the LCD Matrix from sliding around.