Need electronics genius.

[buickanddeere]

I know very little about electronics but once fixed a circuit board in my Genie manlift by replacing a diode that had blown. Skip ahead 8 years and Im again facing a similar problem in the same manlift. This circuit board is the speed controller 36557GT for the boom functions. I again see a blown component on it. They want in the neighborhood of $800 for this little control. I figure Ive got nothing to lose by trying to fix it. My problem is i dont know how to ID the components. My guess is this is a resistor. I can see 4 bands on it. Im thinking you read it from left to right in the picture. Its about 15mm long and maybe 6mm in diameter. Im confused as to how to read it if it is indeed a resistor. Looks like brown, brown, silver or white, and black or brown at the end. I can find no schematic for this little board to help ID it. Can anyone enlighten me or offer any help? Thanks

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Suspect that this is a symptom and not the problem . Possibly that something else has failed and ran excess current through the resistor .

 

[Watthour]

Suspect that this is a symptom and not the problem . Suspect something else has failed and ran excess current through the resistor .

Agreed. It looks like a 5W carbon considering the scaling by the 10K 2W pot adjacent to it. It is a higher wattage resistor because it needs to dissipate some heat. Whatever is in the circuit probably exceeded that and caused the overheat (even the conformal coating is cooked off it). The load could be off-board, since there is only one voltage regulator present (VR1) and no other power switching or amplifying devices on board.

If we could see the foil side of the board it might be more telling.

 

[MarkB_MI]

When I google which way to read the bands, I keep getting answers that a wide band is normally the last band on a resistor. This is whats really confusing me. I see what you mean about the silver and gold being at the end though as well. But then there's the problem as to what the colors really were since its burnt. Looking at them in person , I can see them being multiple different colors before being burnt.
This controller controls a proportional solenoid that controls hydraulic flow to regulate boom speed and is supposedly 24 volt DC.

Even if that's true, I don't think it's a hard-and-fast-rule. Really, the bands only make sense if you assume the silver band is really silver and is the multiplier.

But then there's the problem as to what the colors really were since its burnt. Looking at them in person , I can see them being multiple different colors before being burnt.

Yes, as I think about it, I really think that the first two bands are both red, which means it's a .22 ohm resistor, not .11 ohm. Why? Because .22 ohms is a standard value but .11 is not. And both bands appear to originally have been the same color.

 

[RJKeith]

Do you know anyone with a similar model machine? If so, take a picture of the board with the good resistor and use the chart Janicholson provided to figure out the ohmic value of the resistor to get a replacement. Also you need to get a resistor the same physical size as the one you are replacing as that determines the watts the resistor can handle.