A 2W resistor in a pc ps, o/c with no sign of heating at all,so clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would anyone
know what that value should be ? 3 band accuracy in a pc or is there some
other convention not ordinary 5 band coding ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On Sep 28, 10:30 am, "N Cook" wrote:
A 2W resistor in a pc ps, o/c with no sign of heating at all,so clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would anyone
know what that value should be ? 3 band accuracy in a pc or is there some
other convention not ordinary 5 band coding ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list onhttp://home.graffiti.net/diverse:graffiti.net/

PCs are no different than any other device, resistors are resistors.
Red yellow yellow would be 240k according to my calculations.

http://www.bcdxc.org/resistor_color_codes.htm

wrote in message
ups.com...
On Sep 28, 10:30 am, "N Cook" wrote:
A 2W resistor in a pc ps, o/c with no sign of heating at all,so clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would
anyone
know what that value should be ? 3 band accuracy in a pc or is there
some
other convention not ordinary 5 band coding ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list
onhttp://home.graffiti.net/diverse:graffiti.net/

PCs are no different than any other device, resistors are resistors.
Red yellow yellow would be 240k according to my calculations.

http://www.bcdxc.org/resistor_color_codes.htm


But the point is its 5 bands so 24.4 ohms but the third yellow band implies
accuracy between 2.43 and 2.45 ohms but the silver band implies a value
between 22 and 26 ohms or so - illogical as Mr Spock would say

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

correction - between 24.3 and 24.5 ohms

"N Cook" wrote in message
...
wrote in message


marked bands of red,yellow,yellow,gold, silver.


the third yellow band implies

Read your post. red, yellow,yellow,gold, silver. What third yellow band?
If you're talking about the gold, that'd be the multiplier on a 5-band
resistor, or 10E-1. Silver is tolerance.


I read it as 24.4 at 10% tolerance, so 21.96-26.84.

Dave S.

Dave wrote in message
news:CWaLi.28398$nO3.26820@edtnps90...

"N Cook" wrote in message
...
wrote in message


marked bands of red,yellow,yellow,gold, silver.


the third yellow band implies

Read your post. red, yellow,yellow,gold, silver. What third yellow band?
If you're talking about the gold, that'd be the multiplier on a 5-band
resistor, or 10E-1. Silver is tolerance.


I read it as 24.4 at 10% tolerance, so 21.96-26.84.

Dave S.



alright correction , putting in an apostrophe or two
for
the third yellow band
read
the third, yellow band,

it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which are only
10 percent tolerance?


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

In article ,
"N Cook" wrote:

Dave wrote in message
news:CWaLi.28398$nO3.26820@edtnps90...

"N Cook" wrote in message
...
wrote in message


marked bands of red,yellow,yellow,gold, silver.


the third yellow band implies

Read your post. red, yellow,yellow,gold, silver. What third yellow band?
If you're talking about the gold, that'd be the multiplier on a 5-band
resistor, or 10E-1. Silver is tolerance.


I read it as 24.4 at 10% tolerance, so 21.96-26.84.

Dave S.



alright correction , putting in an apostrophe or two
for
the third yellow band
read
the third, yellow band,

it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which are only
10 percent tolerance?


--

We call those commas, not apostrophes, in the U.S., but I understood
your phrasing the first time. I agree that a precision resistor with a
10% tolerance makes no sense. I'd make it 240K. Fifth band is sometimes
used for reliability (i.e. MTBF) AIUI.

" wrote:

On Sep 28, 10:30 am, "N Cook" wrote:
A 2W resistor in a pc ps, o/c with no sign of heating at all,so clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would anyone
know what that value should be ? 3 band accuracy in a pc or is there some
other convention not ordinary 5 band coding ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list onhttp://home.graffiti.net/diverse:graffiti.net/

PCs are no different than any other device, resistors are resistors.
Red yellow yellow would be 240k according to my calculations.

http://www.bcdxc.org/resistor_color_codes.htm

NO. That colour code chart is not complete.

The gold is the multiplier and silver is the tolerance. Odd to have 3 bands for the digits though, that's normally
only on close tolerance parts.

It looks like 24.4 ohms to me.

This is cute ! Check it out.
http://www.samengstrom.com/nxl/10116...e_page.en.html

Graham

Smitty Two wrote in message
news
In article ,
"N Cook" wrote:

Dave wrote in message
news:CWaLi.28398$nO3.26820@edtnps90...

"N Cook" wrote in message
...
wrote in message


marked bands of red,yellow,yellow,gold, silver.


the third yellow band implies

Read your post. red, yellow,yellow,gold, silver. What third yellow
band?
If you're talking about the gold, that'd be the multiplier on a 5-band
resistor, or 10E-1. Silver is tolerance.


I read it as 24.4 at 10% tolerance, so 21.96-26.84.

Dave S.



alright correction , putting in an apostrophe or two
for
the third yellow band
read
the third, yellow band,

it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which are
only
10 percent tolerance?


--

We call those commas, not apostrophes, in the U.S., but I understood
your phrasing the first time. I agree that a precision resistor with a
10% tolerance makes no sense. I'd make it 240K. Fifth band is sometimes
used for reliability (i.e. MTBF) AIUI.

But why a 2W 240K resistor in something that is unlikely ever to have more
than 350V across it.
I've not taken apart yet so it may well never see any high voltages.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:

it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which are only
10 percent tolerance?

Why do you expect it to make sense ?

I'm sure I've seen 5 band 5% resistors.

Graham

Eeyore wrote in message
...


" wrote:

On Sep 28, 10:30 am, "N Cook" wrote:
A 2W resistor in a pc ps, o/c with no sign of heating at all,so
clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would
anyone
know what that value should be ? 3 band accuracy in a pc or is there
some
other convention not ordinary 5 band coding ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list
onhttp://home.graffiti.net/diverse:graffiti.net/

PCs are no different than any other device, resistors are resistors.
Red yellow yellow would be 240k according to my calculations.

http://www.bcdxc.org/resistor_color_codes.htm

NO. That colour code chart is not complete.

The gold is the multiplier and silver is the tolerance. Odd to have 3
bands for the digits though, that's normally
only on close tolerance parts.

It looks like 24.4 ohms to me.

This is cute ! Check it out.

http://www.samengstrom.com/nxl/10116...e_page.en.html

Graham





a fun app.
Interesting the significance of the wide space between band 1 and 2.
In 4 band useage you would normally read the other way around as the space
would be between the multiplyer and the tolerance band

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Smitty Two wrote:

We call those commas, not apostrophes, in the U.S.

We do in the UK too actually.

Graham

N Cook wrote:

Smitty Two wrote

We call those commas, not apostrophes, in the U.S., but I understood
your phrasing the first time. I agree that a precision resistor with a
10% tolerance makes no sense. I'd make it 240K. Fifth band is sometimes
used for reliability (i.e. MTBF) AIUI.

But why a 2W 240K resistor in something that is unlikely ever to have more
than 350V across it.
I've not taken apart yet so it may well never see any high voltages.

How much experience do you actually have in repair ?

From its location in the circuitry you must have SOME idea of its likely value
from context ! A fusible is normally a lowish value for example.

Graham

In article ,
"N Cook" wrote:

Smitty Two wrote in message
news
In article ,
"N Cook" wrote:

Dave wrote in message
news:CWaLi.28398$nO3.26820@edtnps90...

"N Cook" wrote in message
...
wrote in message


marked bands of red,yellow,yellow,gold, silver.


the third yellow band implies

Read your post. red, yellow,yellow,gold, silver. What third yellow
band?
If you're talking about the gold, that'd be the multiplier on a 5-band
resistor, or 10E-1. Silver is tolerance.


I read it as 24.4 at 10% tolerance, so 21.96-26.84.

Dave S.



alright correction , putting in an apostrophe or two
for
the third yellow band
read
the third, yellow band,

it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which are
only
10 percent tolerance?


--

We call those commas, not apostrophes, in the U.S., but I understood
your phrasing the first time. I agree that a precision resistor with a
10% tolerance makes no sense. I'd make it 240K. Fifth band is sometimes
used for reliability (i.e. MTBF) AIUI.

But why a 2W 240K resistor in something that is unlikely ever to have more
than 350V across it.
I've not taken apart yet so it may well never see any high voltages.


Well, that's a half of a watt. Slightly over-engineered but not
inexplicable. You sure aren't going to put 350 volts on a 24.4 ohm
resistor. And there's no such thing as a four band resistor with 10%
tolerance. My supposition stands.

"N Cook" wrote in message
...
Smitty Two wrote in message
news
In article ,
"N Cook" wrote:

Dave wrote in message
news:CWaLi.28398$nO3.26820@edtnps90...

"N Cook" wrote in message
...
wrote in message


marked bands of red,yellow,yellow,gold, silver.


the third yellow band implies

Read your post. red, yellow,yellow,gold, silver. What third yellow
band?
If you're talking about the gold, that'd be the multiplier on a
5-band
resistor, or 10E-1. Silver is tolerance.


I read it as 24.4 at 10% tolerance, so 21.96-26.84.

Dave S.



alright correction , putting in an apostrophe or two
for
the third yellow band
read
the third, yellow band,

it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which are
only
10 percent tolerance?


--

We call those commas, not apostrophes, in the U.S., but I understood
your phrasing the first time. I agree that a precision resistor with a
10% tolerance makes no sense. I'd make it 240K. Fifth band is sometimes
used for reliability (i.e. MTBF) AIUI.

But why a 2W 240K resistor in something that is unlikely ever to have more
than 350V across it.
I've not taken apart yet so it may well never see any high voltages.



Are you sure it's not the startup resistor, and not a fusible type at all ?
240k at a couple of watts is not unreasonable for a resistor in that
location, and they do go open for no apparent reason, but probably due to
voltage stress, as they do have about 350v across them in normal (UK)
operation. I've always assumed that they tend to use these 'bigger' rated
resistors, as they have a better working voltage rating, although sometimes,
you find two more conservatively rated resistors of 120k each, in series, to
double the voltage rating. You can easily tell if it is the startup
resistor, because one end of it will be connected directly to the "+"
terminal of the main filter cap, or the most "+" terminal if it uses two
stacked caps. Beware if it is an open startup resistor, as the main filter
cap(s) will remain fully charged ...

Arfa

Smitty Two wrote in message
news
In article ,
"N Cook" wrote:

Smitty Two wrote in message
news
In article ,
"N Cook" wrote:

Dave wrote in message
news:CWaLi.28398$nO3.26820@edtnps90...

"N Cook" wrote in message
...
wrote in message


marked bands of red,yellow,yellow,gold, silver.


the third yellow band implies

Read your post. red, yellow,yellow,gold, silver. What third
yellow
band?
If you're talking about the gold, that'd be the multiplier on a
5-band
resistor, or 10E-1. Silver is tolerance.


I read it as 24.4 at 10% tolerance, so 21.96-26.84.

Dave S.



alright correction , putting in an apostrophe or two
for
the third yellow band
read
the third, yellow band,

it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which
are
only
10 percent tolerance?


--

We call those commas, not apostrophes, in the U.S., but I understood
your phrasing the first time. I agree that a precision resistor with a
10% tolerance makes no sense. I'd make it 240K. Fifth band is
sometimes
used for reliability (i.e. MTBF) AIUI.

But why a 2W 240K resistor in something that is unlikely ever to have
more
than 350V across it.
I've not taken apart yet so it may well never see any high voltages.


Well, that's a half of a watt. Slightly over-engineered but not
inexplicable. You sure aren't going to put 350 volts on a 24.4 ohm
resistor. And there's no such thing as a four band resistor with 10%
tolerance. My supposition stands.

I've not removed the security screws yet, just the top cover so don't know
what its functional area is yet.

I looked around all the 5 band resistors that I have laying about , all 1/2
or 1/3W , not 2W, but they are all brown , 1percent, tolerance band which is
logical but silver 10 percent makes no sense at all.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote in message
...
Smitty Two wrote in message
news
In article ,
"N Cook" wrote:

Smitty Two wrote in message
news In article ,
"N Cook" wrote:

Dave wrote in message
news:CWaLi.28398$nO3.26820@edtnps90...

"N Cook" wrote in message
...
wrote in message


marked bands of red,yellow,yellow,gold, silver.


the third yellow band implies

Read your post. red, yellow,yellow,gold, silver. What third
yellow
band?
If you're talking about the gold, that'd be the multiplier on a
5-band
resistor, or 10E-1. Silver is tolerance.


I read it as 24.4 at 10% tolerance, so 21.96-26.84.

Dave S.



alright correction , putting in an apostrophe or two
for
the third yellow band
read
the third, yellow band,

it still does not explain the tolerance illogicality
Why and how would anyone stock a 3/5 band range of resistors which
are
only
10 percent tolerance?


--

We call those commas, not apostrophes, in the U.S., but I understood
your phrasing the first time. I agree that a precision resistor with
a
10% tolerance makes no sense. I'd make it 240K. Fifth band is
sometimes
used for reliability (i.e. MTBF) AIUI.

But why a 2W 240K resistor in something that is unlikely ever to have
more
than 350V across it.
I've not taken apart yet so it may well never see any high voltages.


Well, that's a half of a watt. Slightly over-engineered but not
inexplicable. You sure aren't going to put 350 volts on a 24.4 ohm
resistor. And there's no such thing as a four band resistor with 10%
tolerance. My supposition stands.

I've not removed the security screws yet, just the top cover so don't know
what its functional area is yet.

I looked around all the 5 band resistors that I have laying about , all
1/2
or 1/3W , not 2W, but they are all brown , 1percent, tolerance band which
is
logical but silver 10 percent makes no sense at all.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/




and all those 5 band 1/2 and 1/3W resistors , perhaps 20 different values
and from different sources have the wide gap between bands 4 and 5 , not
between 1 and 2

N Cook wrote:
Eeyore wrote in message
...

" wrote:

On Sep 28, 10:30 am, "N Cook" wrote:
A 2W resistor in a pc ps, o/c with no sign of heating at all,so
clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would
anyone
know what that value should be ? 3 band accuracy in a pc or is there
some
other convention not ordinary 5 band coding ?

Could that last band be a gray instead of silver? That would give you a
..05% precision resistor


--
Steve W.

On Fri, 28 Sep 2007 15:30:13 +0100, "N Cook" put
finger to keyboard and composed:

A 2W resistor in a pc ps, o/c with no sign of heating at all,so clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would anyone
know what that value should be ? 3 band accuracy in a pc or is there some
other convention not ordinary 5 band coding ?

The only places I can think of that would require a precision resistor
(but not fusible) would be the voltage sensing inputs of the PWM
controller IC on the secondary side, or maybe the +5VSB supply. In
these cases precision resistors are usually preferred to trimpots.

If you could describe the circuitry in the immediate vicinity, or
provide a photo, perhaps someone may be able to make sense of it.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Franc Zabkar wrote in message
...
On Fri, 28 Sep 2007 15:30:13 +0100, "N Cook" put
finger to keyboard and composed:

A 2W resistor in a pc ps, o/c with no sign of heating at all,so clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would
anyone
know what that value should be ? 3 band accuracy in a pc or is there some
other convention not ordinary 5 band coding ?

The only places I can think of that would require a precision resistor
(but not fusible) would be the voltage sensing inputs of the PWM
controller IC on the secondary side, or maybe the +5VSB supply. In
these cases precision resistors are usually preferred to trimpots.

If you could describe the circuitry in the immediate vicinity, or
provide a photo, perhaps someone may be able to make sense of it.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Now taken apart and no longer viewing this R skew on.
It is 5 bands as stated but is only 1W.
Doing an axial scrape it was obviously 240K and goes between the rectified
mains + to pin 3 of a 4 pin , TO220 device marked
1HO165B and italic f logo so maybe Fairchild power switch KA1H0165R so
plenty of datasheets,
pin 1 of that device goes to mains rectified -ve

So still a mystery of the gold and silver bands 4 and 5

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N Cook" wrote in message
...
Franc Zabkar wrote in message
...
On Fri, 28 Sep 2007 15:30:13 +0100, "N Cook" put
finger to keyboard and composed:

A 2W resistor in a pc ps, o/c with no sign of heating at all,so clearly
marked bands of red,yellow,yellow,gold, silver.
Before I remove it and make an axial scrape along the coating would
anyone
know what that value should be ? 3 band accuracy in a pc or is there
some
other convention not ordinary 5 band coding ?

The only places I can think of that would require a precision resistor
(but not fusible) would be the voltage sensing inputs of the PWM
controller IC on the secondary side, or maybe the +5VSB supply. In
these cases precision resistors are usually preferred to trimpots.

If you could describe the circuitry in the immediate vicinity, or
provide a photo, perhaps someone may be able to make sense of it.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Now taken apart and no longer viewing this R skew on.
It is 5 bands as stated but is only 1W.
Doing an axial scrape it was obviously 240K and goes between the rectified
mains + to pin 3 of a 4 pin , TO220 device marked
1HO165B and italic f logo so maybe Fairchild power switch KA1H0165R so
plenty of datasheets,
pin 1 of that device goes to mains rectified -ve

So still a mystery of the gold and silver bands 4 and 5


So it is the startup resistor, as I suggested it would be. I would replace
it with two 120k 1 watters in series to double the voltage rating. Watch
that cap "+" terminal when you take your soldering iron to the resistor, for
in that cap lurks lightning ...

Arfa

N Cook wrote:

Doing an axial scrape it was obviously 240K and goes between the rectified
mains + to pin 3 of a 4 pin , TO220 device marked
1HO165B and italic f logo so maybe Fairchild power switch KA1H0165R so
plenty of datasheets,

The startup resistor as Arfa suggested IIRC.

Now that info would have made establishing its value so much easier.

Graham