• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Looking for SA-8500II Advice

Do you have the board removed from the heat sink? If so, give all the solder joints a good look under bright light and magnification for lifted traces (may not be obvious if there’s a large solder blob), bad joints (sometimes identified by what looks like a crack in the solder in a ring shape), and other signs of abuse...darkened areas, etc. especially look at the drivers (mounted to smaller heat sinks) .
 
I didn't see anything, but I don't have a magnifying lens, I think I'm going to go grab one.
BUT one of those drivers you mentioned, on the bottom side of them there is some glue right over the joint. Jus a little dab. I wonder if there was a repair there? It's weird
 
Okay I think I got it! Upon further inspection, one of transistor legs was a little tweaked, I actually noticed that the other day but saw that it was in the socket and didn't think much of it. Just now I thought it looked like it was awfully close to the heat sink, and it's own tab. So I popped it out, carefully bent it straight and put it back in. Checked bias, and it had dropped anothe 12mv from the 30 I had it set perfectly to before..... Put on some tunes and I'm ****ng jamming! No relay, nice and loud.
Petehall and jhue, thanks so much for your help and patience I learned a lot about trouble shoot the past few days! You guys rock.
 
image.jpeg I took a picture of it bent... Strange that I was able to set the bias, and that it was bent, someone must have been in this thing?
 
I think that's the picture, that leg was rotated over so it didn't reflect light like the other two. It's been playing for about and hour and a half now, nice and cool. I'm very pleased. I've always been pretty lucky with gear I buy... A few shots of deposit and I'm in business, this one had me wondering.
 
Glad it’s working now. There's a couple joints in the pic of the board that look suspect. Perhaps you just went ahead and reflowed them while it was out. One specifically at about 2 o'clock from your meter probe looks to be a round circle crack, but perhaps just the lighting and shadows.
 
You must log in or register to reply here.
Back
Top Bottom