|PECHORIN'S home account archive eshop globalmediapro|
On my STR SE501, the rear channels pop out after the device has been left on for a short time. Although I know my way around electronics, and I'm comfortable disassembling and reassembling - my confidence is not very high when it comes to soldering. I'm also going to need to run to the store to pick up a magnifying glass. Below are some pictures of what I have. First, upon close examination with the naked eye, I found this suspicious looking crack under the blue relay nearest my rear channel outputs. Is this the type of thing I'm looking for? (center of pic next to 8610) farm2.static.flickr.com/1371/531881219_8ecccc7cfb_b.jpg Second, the back of the main board looks like it has a hot spot. Is this normal, or do you think this is a problem? All the circuits are probably intact, but there are visible "circles", not quite as bad as the one in the first picture. farm2.static.flickr.com/1406/531776414_1027615ac1_b.jpg I inherited a non-fine-tip soldering iron from my late grandfather that I've never used before. Considering my tools and my questionable expertise, how do you recommend I attack this? I'm tempted to think the crack(s) in the first picture is my only problem - but I'd hate to ignore potential problems. I guess I'm just looking for advice or reassurance. This receiver is several years old. It is on more than its off. It sounds great when all the channels are working, and I think it could have a long life ahead of it.
Exactly - the slight crack (ring crack) around the mid point of the solder joints are cold solder joints and need to be soldered over to reconnect the top of the pin to the bottom of the solder connection. The crack is preventing a good signal. Right off the bat I can see two cold solder joints in your first picture (on either side of the number 8610 on the pc board). I dont know what the hot spot is but I would also guess your primary problem are the cold solder joints. I too had a non fine tip soldering gun (literally looks like a gun w/trigger) and it worked BUT I would not recommend it as it was a pain to be really accurate. The follwoing site has a good tutorial on how to do a decent solder job. Yours is easier because you just have to "recoat" the joint (without getting any on neighboring pcb board strips - the lighter green strips) If you do bridge a strip just slightly heat up the offending solder and gently push away with a not too sharp implement. Essentially you are reheating the joint and addind a small amount of solder to fix. Cold solder joints on these usually come from hotter components affecting the board over time to the point where the joints become self insulating and dont conduct. They essentially "dry out" and crack.