Resistor on famicom to nes adapter board

[sonic2041]

The resistor on my Gyromite adapter board is broken. I would like to replace it with a similar resistor, but I am having trouble deciphering the color code. It appears to be Brown Black Red Gray (or Silver) Brown.

This color combination is kind of hard to figure out. I have guessed that it is a 1K 10% 100ppm assuming that the gray is silver, and the last band is a temp coefficient. I am not 100% sure of this.

I was wondering if someone else you has an adapter board could use a multi-meter to read the resistance value for me, to see if my guess is correct.

Thanks

[Hobie-wan]

If someone else doesn't have one immediately handy, I can look later. It is just buried at the moment.

[sonic2041]

OK, so I was able to find another board and thought I would post this here for reference. The resistor on this one appears to be: Brown Black Red White. It reads as 2.92 Mohm on my multimeter, so who really knows what the colors mean. Also, before I got this one, I used an 1/8W 220 Ohm on my other board and it seems to work flawlessly. The resistor just seems to connect 2 ground points. Before deciding on the 220, I had a 2kohm turnpot connected and the board seemed to function with anything above approximately 150 ohm.

EDIT: I don't know a lot about electronics, so if anybody has any ideas of what is going on here, let me know.

[Hobie-wan]

I forgot to post. One cart is still buried, but the other that I used and made an adapter has a pink body and then the colors are brown, black, orange, blue brown. It read 6.17 M Ohms.

The orange is very reddish and is hard to tell against the pink. The blue is greyish. I'd say mine matched yours, but then we got very different measures.

[sonic2041]

I checked the resistance again and I consistently get 2.7Mohm. The thing that confuses me, is how to interpret the colors to get anything near that, whether its 6.17 or 2.7.

Thanks for posting, its nice to have a comparison and I guess we can conclude that its something in the Mohm range, and seeing as how it works with a 220 it probably doesn't matter much.

[darkcat]

they could be diodes? do a diode check on them some older and smaller diodes used color code the 4 colors are decoded to the n1XXXX values. this would also explain the different measures of the resistance if it was a zener since it will have its NOM .7 drop forward bias and a rated drop reversed bias.

[Hobie-wan]

All the diodes in SNES games I've seen were glass zener ones. They aren't black with the silver stripe either. Unless someone knows if the pink body means something special.

*edit*

Seems pink ones are of the 'wire wound' construction.

[darkcat]

all sorts of colors are used for resistors/ capacitors they mean nothing special do a diode check on it the forward bias would be like .7V or so also the anode will be the side with out the bands 70% of the time so put the + to that side and - to the color side. further expection of the colors leads me to beleve they are diodes the brown will be your first number so NXXXXX do the color code of the rest.
Black 0
Brown 1
red 2
orange 3
yellow 4
green 5
blue 6
violet 7
gray 8
white 9

thing with resistors the last color will normally be gold or silver bands in the case it is not and often only larger more precise resistors will have anything else i doubt they would use a very low tolerance resistor in this application.

I'd say with its a 90% chance its a diode

[sonic2041]

Do diodes ever come in packages that look exactly like resistors?



Which, you could be right that it is, cause I too doubted that they would use 1% resistors.

I did recheck the resistance and one direction its 2.72 Mohm, and the other direction is 41Mohm which is similar characteristics of other diodes.

Thanks for the info, I will look into diodes that look like resistors.

EDIT: I used the diode check function on my multimeter and it is in fact a diode.

EDIT 2: The diode check gives me a value of 0.520V.

[Hobie-wan]

Yay mystery solved and learned something.