I fixed a couple of electronic things today, posting about it here in the hopes that others may find it useful.
The first was a Kenwood amplifier. The remote control stopped working with it. There didn't seem to be anything wrong with the remote itself, so I decided to take the lid off and check the infrared receiver box. This turned out to be a real pain in the ass; they bolted the knob things to the case, the front panel is attached using those easily broken flat wires, and there were about 2 dozen screws to take out.
Refer to the dimly lit picture of the guts of the unit strewn about my dirty carpet:
Anyways, I got it all apart and found the infrared thing, it looks like this:
Flipping the board over, I found that the 3 pins going to that were soldered very poorly, not making good contact to the traces.
So I resoldered the pins, now it works. Yay.
Then my monitor broke. It's an Acer AL2216W. For the past couple weeks, the LED kept turning this dim red color and it was really hard to get the screen to stay on.
I took the lid off and removed the metal panel over the back. I had to take out the screws and bolts for the power plug and video plugs to be able to do this.
See the circled thing? That there is a high voltage capacitor; if you ever go to fix any sort of monitor, once you get it apart, find this big capacitor and short the two leads out using a screwdriver.
If you don't discharge it, and then accidentally touch it, you'll get a nasty burn or possibly die.
Ok so I removed the power board and took a good look at it. One of the capacitors stood out. See that crud at the top? That's electrolyte that leaked out of the vent. Once a cap does that, there's no way it can hold as much charge as it's supposed to.
So I busted out my desoldering iron and removed it.
Whenever you replace a capacitor, always check the ratings. In this case it is 10 volts at 2200uF. 10 volts is the maximum it can store; it will only store as much as the circuit requires. In this case, this part of the circuit only saw 5 volts,so this was OK. The important thing is to make sure the capcitor you pick to replace it has the same, or higher ratings. If it's lower it wont work or will explode.
In this case, I found a 16 volt x 2200 uF one in my parts bin. You could just as easily buy one online at Mouser. Notice how it's next to the heatsinks? That means you should get one rated for the high temperature, which is denoted by the color of the case. In this case, I should have replaced it with a black cap, but I used a blue one because it's what I had on hand. (Do as I say, not as I do!) Honestly if that part of the circuit regularly goes higher than 185*F there would be bigger problems than just the cap..
I put it all back together and now it works. Woo.
