Monday, December 31, 2007

I fixed my JVC AV-36980

A few months ago... several actually. My JVC AV-36980 went out, no reason it just wouldn't turn on. I wanted to fix it but my life was too hectic at the time. Over Christmas break my sons and I finally got around to fixing it. After rolling this heavy unit and entertainment center away from the wall I googled the model number and found this web site. I was amazed, it looked like my exact problem and it looked like something I could do but was a little scary. The good thing is that it would only cost me $1.75 to try.
So first I opened the unit and found these dusty contents.The red arrow points to what I would later discover to be the bad capacitor know as C926.

After vacuuming the main board and back of the unit (being careful to touch anything as a working cap might have a lot of volts in it even after I let it sit for an hour with no power) I found C926 and saw a slight bulge and discoloration. This made me feel good. So I headed to Radio Shack to get the part. After going to a small mall Radio Shack I learned there are different types. The one at the mall had only 2 trays of caps and did not carry what I needed so I went to a larger one with 3 trays and found the 35V 1000uF part.

I needed to get to the bottom of the board to remove and replace the old part so I disconnected the speaker cable (remember which direction it was and where it was) then lifted then slid the board out of its track and put it on its side.
I noted which side was + and - and verified it with the marking on the board then had my son pull on the cap while I heated up the leads one at a time making careful not to overheat the board. This is a through hole part on a board that might be multi-layer. It took several heatings to get the thing all the way out. In other words, when I heated the top lead you could not pull it all the way out with the bottom still attached so you had to heat the bottom while the top hardened.
After getting it out the board showed discoloration. We replaced the part leaving this one about 4mm from the board in case it blows at a later time.

The pictures above where taken with my new DIY protein strobe. The following with the work lamp. This picture shows the cramped work area with the board on the side, I circled the bad leads, use the large trace 'zag' as your landmark.
After soldering in the new part, again being careful not to overheat the board. I have the long leads I need to clip.

When I finished the TV worked again. I think my wife was surprised to see me fix it.
It took longer than 30 minutes but was easier than I expected.

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