Is it possible to have a 100 meg fusible resistor?

[ahodgett]

I'm trying to reset a drive belt unit on a laser printer. Having stripped it down looking for a fusible resistor or similar, have found a big, looks like 1/2 watt fusible? resistor. color coded Brown, Black, Violet, Gold, Black - 100Meg 5% ??? seems very big, and can't seem to source. any help appreciated.
Regards
Arthur Hodgett

 

[Sceadwian]

To get a half watt through a 100meg resistors requires 7000+ volts, and the power is critical for a fusing link not just voltage, I'm somehow doubting that's a fusible resistor. If it is and it fused, something is seriously wrong elsewhere in the electrostatic driver section.

 

[ahodgett]

To get a half watt through a 100meg resistors requires 7000+ volts, and the power is critical for a fusing link not just voltage, I'm somehow doubting that's a fusible resistor. If it is and it fused, something is seriously wrong elsewhere in the electrostatic driver section.

Thanks for that, I've done a bit more research and I'm nearly sure it's an FR100 type fusible resistor as it's dimensions match, but it's the purple or violet 3rd code that's puzzling. I've rebuilt the transport belt without the resistor and it works fine, just still shows end-of-life. The normal way these things work, is the firmware detects a new consumable and blows the fusible link and resets the usage to new, or 100% life. The resistor is just between two contacts on the transport buried way deep to hinder you getting at it, it is not connected to any circuitry on the transport, which sort of confirms my suspicions it's just to make the consumable useless when the manufacturer determines!!. May have to buy a new one, measure the resistor value and then I have a spare, but at £80 sterling, didn't want if possible to do that yet. Any further ideas most welcome. Regards and thanks again for your input. Arthur Hodgett

 

[KeepItSimpleStupid]

It's probably a 10.7 ohm resistor. See: https://www.1728.org/resisclr.htm

Looks like some of the calculators are wrong.

You have 3 digits and a multiplier. It could also be a 0.7 ohm resistor, although It may be wrong too

Brown = 1
Black = 0
Violet = 7

Gold is a multiplier of 0.1 so I get a 10.7 ohm resistor. It looks like some of the Internet calculators are just plain wrong. They say it's an invalid code. It's not.
What's so hard?

100 M resistors would likely be marked different (s1) (s1) (s3) (# of zeros). e.g. 100K = 1003

 

[RODALCO]

Never seen a 100 Meg 1/2 Watt resistor.
It is very likely 10.7 ohms as already suggested.
If the machine works with the shunt which is basically 0 ohms, if it needed 100 Meg the machine wouldn't have worked at all.
10 ohms , hmm 10.7 doesn't fit in the E12, 24 series.

 

[KeepItSimpleStupid]

It fits just fine: http://search.digikey.com/us/en/products/RSMF12FB10R7/RSMF12FB10R7-ND/1687001

A 10.7 1/2 W metal Oxide resistor

 

[Tann-44]

apply your resistor on your meter and set it to 200m range and it will tell you what the value...

 

[ahodgett]

apply your resistor on your meter and set it to 200m range and it will tell you what the value...

The value of the resistor is completely off scale on my DVM > 20 Megs. As I indicated previously it's a fusible resistor which I believe goes to a very high value on being blown. It was the violet 3rd band which confused me and still does. The link from "kiss" to the 1728 site proved very enlightening I wasn't aware just how many possibilities there were to interpret the banding. I had simply been used to the four band scenario of value, value and number of noughts to add on the end and a tolerance band. Anyway, as it's an expensive bit of equipment, so I think I'll buy a spare transport, I'll need one sometime, to measure the value directly. By the way the printer is an Oki C5650 and fooling nearly all the consumables is ridiculously easy and cheap, the print quality is excellent, so have no plans to replace any time soon. Once again many thanks for all the help offered, I never cease to be amazed at the knowledge that's out there.

 

[RODALCO]

Thanks for that link kiss.
I learned something today too.
Didn't know about that R value.

 

[KeepItSimpleStupid]

100 M and greater are typically glass enclosed resistors, although I did purchase a 400 M that was quite large. I've purchased odd resistors at both ends of the scale: a 0.5 ohm 1000 W with taps and a 1 Meg ohm 200 Watt resistor as well as the 400 M resistor.

There are specific "sets" of resistors depending on tolerances, such as 0.1%, 1%, 5%, 10% and 20% and it's the ratios that are generally more important, so a specific value may only be available in say 1%, but decade values are usually available in all sets.