Hey folks,
Done a ton of lurking here, trying to learn. Now I have a pretty low end unit I'd like to try to fix-- a Sherwood s-7025 receiver I picked up for not a lot. I figure this may be a good low-stakes first project. I've soldered caps into speakers before, but this will be the first receiver I've worked on. It came to me with the power switch issue, and when I opened it up the back end of the switch was already in pieces-- looks like someone tried to fix it and gave up. I just added a toggle switch at the back of the unit, works fine.
Here's the situation: receiver powers on, everything works, sound is pretty good. However, the right channel is notably weaker than the left, and one of the concrete block resistors near the big caps is getting nuclear HOT-- and the leads to that resistor show notable green corrosion. The picture shows the resistor at the upper right-- 300 ohm 5w. The other resistor at upper left gets uncomfortably warm, but the first one will instantly burn you. You can just see the green corrosion on the left side lead in the picture.
I can't find a schematic for the 7025 anywhere--- does anyone have a lead? Is there a Sherwood receiver that has a similar layout?
Was going to start by replacing the big 1500 uf 50v cap-- there's a matching one linked through on the other side of the board, so I would replace that too. Would move on to the small 103p ceramic caps in a row on the right side of the picture-- not sure what those little blobs are on the lower two. Seem like glue rather than something leaking...
Thanks for any thoughts....
N
Done a ton of lurking here, trying to learn. Now I have a pretty low end unit I'd like to try to fix-- a Sherwood s-7025 receiver I picked up for not a lot. I figure this may be a good low-stakes first project. I've soldered caps into speakers before, but this will be the first receiver I've worked on. It came to me with the power switch issue, and when I opened it up the back end of the switch was already in pieces-- looks like someone tried to fix it and gave up. I just added a toggle switch at the back of the unit, works fine.
Here's the situation: receiver powers on, everything works, sound is pretty good. However, the right channel is notably weaker than the left, and one of the concrete block resistors near the big caps is getting nuclear HOT-- and the leads to that resistor show notable green corrosion. The picture shows the resistor at the upper right-- 300 ohm 5w. The other resistor at upper left gets uncomfortably warm, but the first one will instantly burn you. You can just see the green corrosion on the left side lead in the picture.
I can't find a schematic for the 7025 anywhere--- does anyone have a lead? Is there a Sherwood receiver that has a similar layout?
Was going to start by replacing the big 1500 uf 50v cap-- there's a matching one linked through on the other side of the board, so I would replace that too. Would move on to the small 103p ceramic caps in a row on the right side of the picture-- not sure what those little blobs are on the lower two. Seem like glue rather than something leaking...
Thanks for any thoughts....
N
