Value of resistor - Page 1
Forum section: electronics / beginners

author: giosif
author_rank: Frequent Contributor
timestamp: January 04, 2017, 10:06:48 am
content: Can someone please confirm the value this resistor should have?If I'm reading the bands code correctly, this should be a 680with a 10% tolerance.However, measuring it with my meters, the resistor measures 1.2 kinstead.Just looking to confirm the resistor is faulty, as I suspect.Also, any ideas how I could find out the power rating of this resistor?Thanks!

author: kiran_shrestha
author_rank: Regular Contributor
timestamp: January 04, 2017, 10:51:10 am
content: Is it blue gray brown or violet gray black.... really got confused. Any way may be you have fried you resistor and meters showing high value for it.

author: TheDane
author_rank: Regular Contributor
timestamp: January 04, 2017, 11:10:24 am
content: It looks blue gray brown silver to me = 680 ohm, 10%If pulsed with high voltage spikes, they are known to rise in valueWattage is possible to deduct from measuring it:http://audiokarma.org/forums/index.php?threads/old-harman-kardon-integrated-need-resistors-but-what-wattage.634212/My guess is 500mW - but get out your ruler, and ruleBtw -https://en.wikipedia.org/wiki/Electronic_color_code- for those who are new to pretty rings

author: Ian.M
author_rank: Super Contributor
timestamp: January 04, 2017, 12:18:07 pm
content: Assuming that's normal ruled paper I concur with 1/2W. If size is important to a component image, *PLEASE* either give dimensions, or photograph on a background of squared or graph paper and give the square size.

author: SeanB
author_rank: Super Contributor
timestamp: January 04, 2017, 02:11:19 pm
content: 680R 10% carbon composition, and it has been running hot. Best is to replace with a 680R 0.5W 1% metal film, not that you need the 1% but that 1% or 2% is about the cheapest in 0.5W metal film commonly around.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: January 04, 2017, 02:31:50 pm
content: I looked at your second picture first and viewed the third color band as black, making it a 68 ohm resistor. The first picture is more ambiguous, possibly brown which would make your 680 ohm interpretation correct. Either way it is defective.If you cannot verify the color of the third band better than I can in the photos I would look at other methods to confirm the proper value. Possibly purchase both values, and test operation with both. Or identify the application of this resistor and ask on this forum. Or find another example of the circuit or a schematic.

author: Ian.M
author_rank: Super Contributor
timestamp: January 04, 2017, 02:39:50 pm
content: The coloured (off-grey) background probably upset the camera's auto colour balance. I'd trust the second image's colours more because of the white paper background. If in doubt, see if you can find any other resistors in the equipment of the same type, with black or brown bands and compare colours side by side (in-situ). Otherwise ask here, giving circuit details, which possible value is safest to try first.

author: giosif
author_rank: Frequent Contributor
timestamp: January 05, 2017, 12:34:43 am
content: Quote from: kiran_shrestha on January 04, 2017, 10:51:10 amThat is what I was looking to confirm, as I'm not too good with colors and the low "intensity" of the colors used on this resistor doesn't help either.Quote from: TheDane on January 04, 2017, 11:10:24 amThank you for that!Most useful information.I confirm this is the size of a 1/2W resistor.On the electronic color code, I was aware of it, but my challenge was mainly on identifying the correct colors on this resistor.Quote from: Ian.M on January 04, 2017, 12:18:07 pmAgree with providing dimensions, just wasn't sure to what degree there was a correspondence between that and the power rating (i.e. if the dimensions are "standard" for a given power rating).Quote from: Ian.M on January 04, 2017, 02:39:50 pmI used my phone to take the photos (don't have a camera at this point in time), but the problem is with the colors on the resistor itself, rather than the color balance: even with the naked eye, it is difficult to tell what color some of the rings are (for me, anyway).The circuit is the analog part of the Solartron 7060 multimeter for which I don't have any schematics and/or manual.But there's another resistor (metal film, by the looks of it) right next to this one which is also 680.Quote from: SeanB on January 04, 2017, 02:11:19 pmOk, thank you for the confirmation and replacement recommendation!Quote from: CatalinaWOW on January 04, 2017, 02:31:50 pmThanks, but I am fairly confident now that it is a 680resistor.As I mentioned above, this is from a Solartron 7060 multimeter for which finding the manual or schematics seems to have fewer chances than winning at the lotery.Thank you all who responded!