by Javajesus »
Sat Mar 13, 2010 8:40 am
Ok, So I decided to replace all the caps in my amp from my STD3 (its an SHP3 amp) I used the parts guide posted on Tony's Arcade site. I compared the values to the caps as I removed to make sure everything was cool. I replaced the caps, and met resistors as well as the driver transistors on the driver board, the caps on the pre-amp board, the caps on the inner chassis and the caps and transistors on the outer chassis. When I plugged the unit in a small stream of smoke appeared from the outer chassis transistor heat sink. I pulled the heat sink off and found that the smoke was coming from a resistor on the back side. I have posted a picture. I also found a couple of odd items that did not look normal. First on the driver board, there is a ceramic cap soldered with the #3(from left) transistor, but the actual numbered location is empty with factory solder covering the holes. Second, there is a fuse soldered between two terminal strips. The fuse body is empty, but had a fuse holder attached to it with a blown fuse in it. The unit functioned before I rebuilt the amp. My best guess on the fuse is that it is for the paging amp, whatever that is. I am hoping someone can shed some light on where I went wrong (if I did) and how I can figure out the problem. Sorry for the long post, just alot of information.
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Attachments
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- Picture of the odd capacitor placement and where I think it should go.
- amp3.jpg (66.13 KiB) Viewed 1401 times
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- Picture of the strange fuse. Fuse holder fell apart when I removed it.
- amp2.jpg (374.96 KiB) Viewed 1401 times
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- Cooked resistor. This is on the left side of the heat sink in the middle.
- amp1.jpg (292.43 KiB) Viewed 1401 times