Resistors

Are they all the same?

tim

This may help http://http://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-resistor-color-code-4-band.

Tim

Find out what caused the old ones to become so cruelly baked?

Black 0

Brown 1

Red 2

Orange 3

Yellow 4

Green 5

Blue 6

Violet 7

Grey 8

White 9

To glance at them they might be 1/2 watt metal-films, but that is just a guess.  How many bands needed to specify the value is a function of the precision of the resistor.  Sometimes there is a lonely metallic band that specifically addresses tolerance, sometimes there is a solitary band associated with the thermal drift characteristics of the device, but this can be a little more manufacturer-specific.

Laser marking came to dominate in the market later on.

Carbon resistors used to have a brown body often.  These are low-inductive and cheap.  They have an additional noise term as regards other types.

Blues and Greens typically indicated some sort of metallic construction.  These were pretty stable.  Wirewound is a type, a subtype is counter-inductively-wound types.  Metal film, thin film and thick film depending, mostly on value, were naturally low-inductive.

Tim,

That link tells my Pc it is not connected, he he he, it is or I won't be here and yes they are all the same..

Don,

This board is from the mid 80's, they are the way they are from many years of heat and they are not bad as far as I know cause the board is still good but I have it out so I want to replace the ones that look bad..

1.2 and 2.2Ks, looks like.  Got an ohmmeter?

One thing to try is to pick a resistor that doesn't look too bad, polish its leads with a pen eraser, clip one of them and measure it.  Then you can infer the coding scheme.   This wont hurt anything because you are going to replace them anyway.

Yes they all measure the same even the very bad looking ones @ 2.2k but where did U get the 1.2 from, they all look the same to me?  And do U stick with 1/2w?  The new ones will be smaller then the old one will they not?

Hi Jay, It looks to me like the heat has also carbonized your board somewhat. This weakens the board and may cause the pads to come loose when you try to remove the old parts. In circumstances similar to this I have clipped off the old resistor and soldered the new one to the lead wires of the old one with out disturbing the board or the old wires soldered to it. This also helps the new resistors dissipate heat as they are in the air away from the board. The reason Don mentioned 1.2 K is that some of your resistors are so cooked that the first Red band looks Brown.

John

This <<<<<<<looks to me to be what i would use to replace them with,:

I may be wrong with the conversion, but they should be correct.

How i would do it is, solder the new resister onto the old axel leads, than after everything is soldered,

snip the old resistor off. that way you wont bother the traces hopefully.

I have learned this from experience, the hard way.

Using the old resistor as a sort of heat sink until you are done.

I hope this helped.