Nokia 445Pro

This is a great monitor, but one day, it began to exhibit image irregularities - the picture would get squashed at the left and right sides, and stretched in the middle, as if someone were grabbing it and pulling it apart. Hitting the monitor would actually make the problem go away momentarily - my online research indicated then that this was likely something simple like a small crack, or a bad solder joint. It turned out to be both - a single cracked solder joint.

As I encountered some snags along the way, I figured that it might be helpful to post what I found out. The first, and one of the most difficult problems I encountered was fairly simplistic - I couldn't get the cover off. There are two screws on the back, which come out easily - they're just Philips head screws. But then came a long period of prodding and prying, which netted nothing. Then I chanced upon a post at a monitor-repair forum that was very helpful.

There are 4 small notches visible on the sides of the monitor, in the seam between the two sections of plastic casing. I had no idea what to do with them though, as I couldn't see anything that would help me figure out what kind of clips were used. And I didn't want to just jab long metal objects into the case, not knowing what was in their path. That's where the forum posting came in handy. It seems that what I didn't want to do is exactly what had to be done - jab something into each of the notches. This is what is inside:

Clip, Inside Clip, Inside View of Outer Cover
On the left is what's inside the front plastic section, and on the right is the inside of the other half of it. The clip simply needed to be pressed in all the way, and it releases. Pushing a screwdriver into the notch would hit the clip, bending it inward, thus releasing it from the small protrusion inside the casing. There was no danger of harming anything either, as the clip is fairly thick, and right behind it is a heavy metal shield.
There is that shield, or rather, both shields. The part closest the camera is sheet metal, almost like metal roof flashing - nice and sharp around the edges, and held in place by at least 15 screws.

Complete Assembly, Top View
There's the inside of the monitor, as seen from what would be the top, were it not setting on the screen. You'll notice a big metal shield around the bottom of the image - that entire thing needed to be removed to allow for the extraction of the largest circuit board. The main CRT plug and the beam landing circuit needed to be disconnected as well, since they had wires running to the main board. The CRT needed to be discharged (which it seemed to have done by itself anyway) so that the anode wire could be removed.
Trinitron Label
There's a shot of the label on this excellent, genuine Trinitron tube.

CRT Plug, From Right Side
There's the CRT plug; forgive the bad focus on this picture. Macro mode was a new thing for me when this monitor needed repairs, and you'll not find me taking the thing apart just for one picture!
CRT Plug, From Left Side
There's a shot of the plug from the other side.

Beam Landing Board
This small circuit board houses the beam landing circuits

Deflection Circuitry, Side View
This is a side view of some of the deflection circuitry.

Power Circuitry
Here's a side view of a bit of the power circuit.

Deflection Circuitry and Flyback, Top View
There's a top view of the flyback, and some of the deflection circuit.
Main PCB, With Plastic Backing
This is the back of the main PCB, showing the black plastic backing that helped secure the board.
Main PCB, Near Flyback
Another view near the flyback, with some of the power circuit in the back.

Video Board, Covered
This is the shield that covers the video circuit board.
Video Board, Top View, Uncovered
There's the top of the video circuit; there's a block there that screws right into a metal shield, allowing it to act as a heatsink.
Video Board, Bottom
And here's the bottom of the board, as it sits mounted to a metal plate.

Yoke Controls, Back View
There's the back of the yoke controls, and a view of the yokes themselves..
Yoke Controls, Uncovered
And here's the bare yoke controls.
Yoke Controls
Another shot of the side of the covered board.

Black Straw Astray
At one point, before ever even opening the monitor, I thought that the problem might be dust accumulation trapping heat, so I gave it a few shots of canned air through the topside vents. But as I was repositioning the can for another blast, the plastic straw popped out and fell right into the monitor. So I then was given two reasons to pop the case open. Granted, the straw is an insulator, but there are plenty of hot spots in the monitor - last thing I needed was a piece of plastic melting itself to my monitor's guts. Finally, at some point in the surgery I noticed the wayward piece just sitting there, out of the way.

Degaussing Effects, Before Degaussing Effects, After
During my troubleshooting, I'd need to rotate the monitor from upside down, rightside up, etc. Well on the first rotation, I noticed that the color was completely screwed up. But then I remembered reading somewhere that Earth's magnetic field could affect monitors when they were reoriented. Both screens here are showing the same thing - the left was before the degaussing. One thing I noticed about this monitor - its degaussing cycle is a good bit longer than cheaper monitors. A lot of monitors I've seen will take only maybe 2 seconds to degauss. This one takes a little over 8 seconds.

Now, finally, after much rapping at the back of the big circuit board, in the area of the deflection circuit, I got closer and closer to an area that would require ever decreasing amounts of jarring to produce glitches in the image. So, I started tapping individual solder joints until I found one that required only a tiny amount of pressure to affect the image. It was a rectangular capacitor, C228. The joint actually sparked a bit when it was wiggled. I merely needed to reheat the solder joint, add a little more solder for insurance, and the monitor was fine. The picture was stable, and no amount of prodding or jarring would affect the image on the screen. That was it - all this over one broken solder joint. And it wasn't a cold solder joint either; it was nice and shiny like it should have been. I guess the stress of multiple heatings cooling cycles, and the above-average amount of time it spent in shipping during its life finally took its toll.

Bad Solder Joint Bad Solder Joint, Topside
There they are - pics first of the solder joint, and then of the capacitor that it's attached to - C228.
Once that joint was resoldered, and I was convinced that that was all there was to it, I put the monitor back together, and set it back on its rightful place on my desk.
And so this tale ends. Hopefully the next journey this monitor takes will be to a recycling center when it is no longer able to put out light.

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