Bose Car Stereo - 1996 - Page 1
Forum section: electronics / beginners

author: jennifergib7
author_rank: Newbie
timestamp: June 02, 2014, 12:08:39 pm
content: I would like to try my hand at repairing a stereo from my daughters car. I have never soldered or worked with electronics, however I am a DIY'er by direction. She has a BOSE CN555 1996 CD/Cassette/AM-FM Radio in which the display freezes and the additionally the control volume button is unstable/unpredictable. I have found some information on the internet as to replacing two of the resistors on the board. The resistors are 47 ohms at 1/2 watts, I believe 471 or 470. In pictures of the circuit board from the radio, they depict this resistor being 'square'. I have been online trying to find a matching resistor and I only find 'round-oblong' resistors in this measurement. My questions are:A) Would this be compatible to use as a replacement?B) Is this a project for someone with zero experience, I do own a multi-meter?C) Any recommended basic articles for reading to ensure my success in this endeavor?Thank you

author: VK5RC
author_rank: Unknown
timestamp: June 02, 2014, 12:25:21 pm
content: Some of the consumer electronics are not made for easy repair, it could be a big project. Making sure you have found the problem is the hard part.You will likely need a GOOD soldering iron( temperature controlled), light with magnification and some prior experience in soldering if replacing those resistors does the trick.Some photos of the radioLinks to the other sites that delineate the resistors as the issueA schematic of the radio if you have one or can find one,These above will greatly aid others who I am sure will try to help.Robert

author: corrado33
author_rank: Frequent Contributor
timestamp: June 02, 2014, 11:18:47 pm
content: To answer your questions.A. The only square resistors I know of are power resistors (rated at many watts). If you found 1/2 W 47 and 470 ohm resistors they should work.Digikey is one of the major suppliers of components online (however you should be able to find those resistors at your local radioshack/electronics store.) If not, here's a link to a digikey search with 1/2 W 47 and 470 Ohm resistors. The resistors are a few cents a piece. (Just make sure you don't try to buy the ones with a 5,000 minimum order quantity.) I'm making the assumption that these resistors aren't special, but they very well may be, so I can only be sure once you post pictures.http://www.digikey.com/product-search/en?FV=fff40001%2Cfff80482%2C4021b%2C40459%2C80005&mnonly=0&newproducts=0&ColumnSort=1000008&page=1&stock=1&pbfree=0&rohs=0&quantity=&ptm=0&fid=0&pageSize=50B. If you own a multimeter, you can actually check the resistors before you buy them or try to desolder them from the board. Simply place the multimeter into ohms mode and put one lead on each side of the resistor you want to check. If the multimeter has multiple ranges (100 Ohm, 1000 Ohm 10kOhm etc.) make sure you put it in a range that will give you relevant results (1000 Ohms would probably work for you assuming your multimeter has 4 digits.) (You can't hurt anything if it's in the wrong mode for ohms, so no worries.) Do this with the radio OFF and NOT plugged in. (Don't measure resistance with power to whatever you're measuring.)C. As for articles... not really? Your best bet would be to post the model of the radio or links to the sites where you found the solutions of replacing those resistors.I find it odd that resistors would fail... My first guess is always capacitors (the big round cylinder things.) But then again, I haven't repaired that much equipment.I agree with Robert above, if you want our full help, you're going to have to provide a bunch more information, and pictures would be absolutely great! I'd definitely start by posting the model number of the stereo and pictures if you can!

author: Swake
author_rank: Frequent Contributor
timestamp: June 06, 2014, 09:41:03 am
content: 'square' -> might be SMD form factor as well. the nomenclature 471 is typical for SMD and would dictate this is a 470 Ohm resistance. Pics please so we make sure.If you've never done this kind of stuff find yourself some old (eventually broken) gear so you can train yourself in soldering skills. On the other hand if the resistances are really the only issue, this is not a very difficult repair.A multimeter and associated required knowledge on how to use that thing will help, but not much.ps: Play safe and prepare to buy a new radio for her birthday or Christmas.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: June 06, 2014, 11:39:19 am
content: The CN55 is made by clarion ,model PN-2121D .Theres a schematic available,its in 2 parts as the PN-2121K version goes with PN-2121D .The second pdf is too large to attatch ,heres a link to it on elektrotanya -http://elektrotanya.com/clarion_pn2121k.pdf/download.htmlThe parts should have a number silkscreened onto the pcb .