lenovo smps repair , trouble identify the resistors

[BeetleJuice]

hi there ,
i try to repair that smps , these two resistors (R10/R15) show 0.2ohms when desoldered from pbc.
i try to decode the colors but i am confused ! that silver in the middle doesnt make sense at all..

the smps had a mosfet burned , you see the x in the HS (IRF740).the other mosfet far left is K3934 and in the middle is a B129N diode.

thank you for the help in advance!

[BeetleJuice]

I believe its:

brown black gray gold green = 10.8 ohm 0.5%
black purple gray gold green = 7.8 ohm 0,5%

can someone verify this? it looks more like silver band but probably its gray.

[PKTKS]

I believe its:

brown black gray gold green = 10.8 ohm 0.5%
black purple gray gold green = 7.8 ohm 0,5%

can someone verify this? it looks more like silver band but probably its gray.

The first one should be OK - in doubt I would measure it
The second one makes no sense.

Paul

[wraper]

0.1 OHm and 70 mOhm. These are not 5 band resistors. Green band should indicate resistor type, nothing to do with resistance. FYI resistors don't fail short.

[PKTKS]

0.1 OHm and 70 mOhm. These are not 5 band resistors. Green band should indicate resistor type, nothing to do with resistance. FYI resistors don't fail short.

Hmmm  they look like old style classic wire wound type
in something like a "new"  2Watt rating..

Do you have some table for these color codes?

Paul

[wraper]

0.1 OHm and 70 mOhm. These are not 5 band resistors. Green band should indicate resistor type, nothing to do with resistance. FYI resistors don't fail short.

Hmmm  they look like old style classic wire wound type
in something like a "new"  2Watt rating..

Do you have some table for these color codes?

Paul

Most likely it's not power rating or any parameter. Say you can find in datasheet that this particular resistor series have green band. Consider this band non standard.

[wraper]

Here is example http://www.farnell.com/datasheets/87422.pdf.

MARKING
The nominal resistance and tolerance are marked on the resistor using four colored bands in accordance
with IEC publication 60062 “color code for fixed resistors”. There is a fifth white band in order to indicate the
type of resistor. Standard values of nominal resistance are taken from the E24 series for resistors with a
tolerance of ±5%. The values of the E24 series are in accordance with IEC publication 60063.

[BeetleJuice]

0.1 OHm and 70 mOhm. These are not 5 band resistors. Green band should indicate resistor type, nothing to do with resistance. FYI resistors don't fail short.

Hmmm  they look like old style classic wire wound type
in something like a "new"  2Watt rating..

Do you have some table for these color codes?

Paul

omg how is this possible! since I don't have a milliohm meter I guess the 0,2 ohms i read with my multimeter shows that these resistors are ok.
they drive the two mosfets I think, I am not sure I should make a schematic to see the wiring.

i cant understand why these are not 5 band resistors, i mean what tells us that these are not? maybe the silver band that makes no sense?
you must be right, cause its impossible to have 2 resistors short to 0,2ohms the same time, so the most logical explanation is that they are sub-ohm resistors so my multimeter and the resistor table i am looking is wrong.

thank you for the reply!

[BeetleJuice]

0.1 OHm and 70 mOhm. These are not 5 band resistors. Green band should indicate resistor type, nothing to do with resistance. FYI resistors don't fail short.

any idea what these resistors are doing with so small value?

[wraper]

0.1 OHm and 70 mOhm. These are not 5 band resistors. Green band should indicate resistor type, nothing to do with resistance. FYI resistors don't fail short.

any idea what these resistors are doing with so small value?

Likely current sense at MOSFET source.