JVC TH-M505 No Sound
It is possible that a fuse has blown in the sub-woofer box. This unit has the entire amplifier built right into the sub-woofer. It also has a number of fuses in it. I have found that over the years fixing these units that if a fuse is blown you will also have more serious problems in the amp circuit. That is usually why the fuse will blow. They sometimes even have a problem in the main head unit with a digital transistor that is a surface mounted transistor that will cause this problem also. This transistor is part of the turn on circuit that signals the sub-woofer to turn on when the head unit is turned on. None of these problems are an easy fix I am sorry to say.
If you have at least a little experience with electronics and the right tools, like a multimeter and soldering equipment, I may be able to help you figure out the problem. But be aware that these are not easy to fix, and you may spend lots of time trying to figure it out just to find out that you will still need to take it in to a service center and in many cases when somebody tries to fix these type of units and have no experience with them they often cause more problems than they have started with.
For starters you can at least check the fuses, but please be sure to unplug the entire unit from the wall outlet before doing anything, there is a big risk of electrical shock.
The bottom of the sub-woofer has 6 screws in it (If I remember right) and those 6 screws must come out, they are rather big and you must use a number 2 phillips head screwdriver. Then after that you must take out all the screws from around the edges of the black metal panel where the speakers plug in to. When those are all out you can pull the amplifier unit right out of the sub-woofer box. Be careful when you pull it out, you will need to unplug a set of wires to get it all the way out, maybe two sets of wires, I am going off of just my memory right now, but if you need more help I will look up the service manual to help you more.
You will find at least one fuse right near the board where the A/C plug goes to and then you will find a few more fuses on the board that is on the right side while looking at the amp block from the same position you pull it out from and this board is plugged into the bottom board and is vertical but the short side is up and down, the long side is going towards the back of the amp and it is running along the metal chassis on that right side.
I hope this helps you, if you need more help just post your questions here.
Nov 26, 2008 |
JVC TH-M505 System