Recently, I was given this Infinity sub because it didn't work. The original owner had always planned to repair it, but never got around to it and with spring cleaning it had to go.
I brought it home and plugged it into my old Sony's LFE out to see what's going on. The sub powered on and went into standby as indicated by the red light on the amp. However, I noticed the light would flicker to green and back to red with the sound of a relay activating and releasing as the occasional lower frequencies of a tv broadcast were going to the sub. I tuned the dish box to an action movie and turned up the sound. The sub turned full on and started producing some sound with authority never going into standby. When I turned the volume down it started going back to standby and you could hear the relay clicking on and off, however, the volume was loud enough that the sub shouldn't be deactivating. I had to give this thing some decent volume to stay active.
When I tore it down this is what I discovered. This cap, C72 has swollen and burst. (Fig 1) The bottom view showed another problem. A surface mount cap, I believe C71, has also give up the ghost. (Fig 2) There is also a full bottom view of the board (Fig 3) and full top view (Fig 4).
1)
2)
3)
4)
Replacing the electrolytic on top is not an issue. Should be an easy endeavor. The surface mount has me concerned. I have no way to identify it, but it does appear to be about the same as C74 at the top of figure 2. Any help you guys could provide would be extremely useful. Thanks in advance.
P.S.
I did find a service manual for the sub on manualslib.com https://www.manualslib.com/manual/910415/Infinity-Entra-Sub-Two.html However, it doesn't appear to include all of the information about C71 and C74. They are excluded in the parts list on page 22 (23 on website). Looking at the diagram on page 25 (26 on website) I can see they are 0.1uF, but nothing else.
I brought it home and plugged it into my old Sony's LFE out to see what's going on. The sub powered on and went into standby as indicated by the red light on the amp. However, I noticed the light would flicker to green and back to red with the sound of a relay activating and releasing as the occasional lower frequencies of a tv broadcast were going to the sub. I tuned the dish box to an action movie and turned up the sound. The sub turned full on and started producing some sound with authority never going into standby. When I turned the volume down it started going back to standby and you could hear the relay clicking on and off, however, the volume was loud enough that the sub shouldn't be deactivating. I had to give this thing some decent volume to stay active.
When I tore it down this is what I discovered. This cap, C72 has swollen and burst. (Fig 1) The bottom view showed another problem. A surface mount cap, I believe C71, has also give up the ghost. (Fig 2) There is also a full bottom view of the board (Fig 3) and full top view (Fig 4).
1)
2) 3) 4)Replacing the electrolytic on top is not an issue. Should be an easy endeavor. The surface mount has me concerned. I have no way to identify it, but it does appear to be about the same as C74 at the top of figure 2. Any help you guys could provide would be extremely useful. Thanks in advance.
P.S.
I did find a service manual for the sub on manualslib.com https://www.manualslib.com/manual/910415/Infinity-Entra-Sub-Two.html However, it doesn't appear to include all of the information about C71 and C74. They are excluded in the parts list on page 22 (23 on website). Looking at the diagram on page 25 (26 on website) I can see they are 0.1uF, but nothing else.
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