How do you get access to the 1.6a fuse
I found this online. I didn't write it, I didn't try it, but it sure sounds good.
First off, I had same problem with an old LifeStyle Series 12 and trying to get in to that case is like trying to get in to Fort Knox... I found these answers on a forum.. I wanted to let you know I didn't not discover them myself but it worked for me.. Also my fuse was bad... I am off to the electrical supply house as soon as I finish typing.. Without further ado:
OK Fellas (and Ladies), here's more detail on the blown fuse fix:
1. You can find the 'plastic swivel tab with notches' by looking for gear teeth in the top rear of the unit. To provide some context, I've placed the subwoofer with the serial number side down, horn is up-front and treble/bass dials on the left. Remove the dial knobs.
2. Now place the unit flat with the horn-side down. Literally use a tennis shoe to spank the plastic cover (on the same side as the gear wheel) in a 45 degree upward motion so the RCA plug holes in the plastic cover are dislodged from the jacks and the unit pops off. One good spank does the job *hee hee*.
3. 2 screws will be visible at the top of the green circuit board. Unscrew these and remove cable ribbons that attach circuit board to other pieces of the unit.
4. The fuse is a cylindrical glass piece, 5mmx20mm. Mine was burnt and coils were missing, an obvious sign of a blown fuse.
5. Don't go to radio shack to find a replacement. They are seriously under-equipped to assist. Go online or to a real electrical supply store to get a 3Amp, 250 Volt 5x20mm slowblow fuse. Don't try to call Bose either because this will inevitably result in more pain. They will try to coax you to order an owner's manual for $10 to get the part number, so you can pay an inflated rate to get the same piece from them. Grrr.
6. I saved $200 - thanks to all contributors on the board. Good work.
7. If this advice helps you, do something nice to help a homeless or mistreated animal. Humans can never be too kind to the rest of the creatures on this planet
OK, Bose owners out there listen up and listen good. Here's the real scoop on 1.(getting access to the inside of most bose subwoofers, 2.( repairing said subwoofer.
Follow these steps in removing the cover of your subwoofer. Unscrew the two screws from the cover. (They are on the input/output side of the cover) Remove the two knobs (Bass and treble volume). On the opposite side of the cover, (put those damn shoes back in the closet) there is a lockout tab that needs to be swung out, it moves 90 degrees in a counter-clockwise direction and is located under the center of the cover. A small flat blade screwdriver works great for swinging this tab out and will be necessary for the next step (the screwdriver that is). On the same side (opposite the input/output side) there are two small tabs near the edges of the cover, one on the right and it's counterpart on the left. If you look closely in the gap between the cover and the sub itself, you will see these 3/8" wide tabs near the edges and towards the top of the cover. With the flat blade screwdriver, put the blade between the cover and on the tab and pull down. Then with your hand balled into a fist, gently hit that side of the cover towards the input/output side. the cover will move only slightly but the tab should remain depressed. Do the same procedure on the opposite side of the cover and it will slide about a 1/2 to 3/4" towards the input/output side and can then be removed by pulling it straight up and off of the cabinet.
Yay! If you get this far without incident then you are ready to implement repairs. In the case of the AM15's, normally what happens is a resistor will open up and prevent the triac (turn-on device) from firing. The fuse is on the underside of the PC board and this above mentioned resistor is a 100 ohm, surface mount "chip" resistor on the top side of the PC board. It will not appear to be bad but trust me, if the fuse is good and the sub will not turn on... replace it! You don't have to use a chip resistor since as a consumer you may have a rough time finding one but a 1/8 watt or 1/4 watt resistor you can find at any Radio Shack will work just dandy in this application. Cut the leads short and solder the two cut leads to the pads on the circuit board where the chip resistor is currently sitting. The chip resistor will be black, about 1/4" long, 1/8" wide and have "101" printed on it's surface. On some models they used two 200 ohm resistors in parallel but the result is the same. One 1/4w axial lead resistor will do just fine. Plug it up and give it a try. (Before you replace the cover).
Secondly, if the fuse is blown on a "Lifestyle" Bose subwoofer, contrary to popular belief, it blew for a reason. The speaker outputs and the subwoofer output devices are TDA7294 IC's with TIP142 and TIP147 Motorola transistors used as current supplements to these said output devices. If the fuse is blown and replacing it only results in another blown fuse then chances are good that one or more of these are blown. In some cases it's very easy to tell, the front of these IC's will be blown off and/or you will see burn marks on the board where they are mounted. These devices are located inside the amp portion of the subwoofer. (The black metal heatsink underneath the input/preamp PCB. As a consumer, if the fuse is blown, unless you are familiar with soldering techniques and troubleshooting electronics, leave this to the pro's. It isn't as easy as you might think and you can destroy the PCB in your attempts to repair it.
On Lifestyle 25II and Lifestyle 30II systems there is a problem with the surround portion of the sub system. Inside on the surround PCB there is a 400 MHZ crystal that clocks converted (to digital format) audio signals through the surround processing area of the sub. These crystals fail and the system, although it powers up just fine, has no output at all or it is intermittent
Feb 25, 2011 |
Bose Lifestyle 12 System