Hi, I'm Andy from SC. I know very little about electronics and I have a question. The resistor in the pic is open. Can anyone tell me the wattage and resistance? Thank you.
Whirlpool Oven/Microwave board repair
Hi, I'm Andy from SC. I know very little about electronics and I have a question. The resistor in the pic is open. Can anyone tell me the wattage and resistance? Thank you.
Last edited by surfref32; 1st December 2009 at 08:44 PM.
Edit, lazy error.
Last edited by ke5frf; 4th December 2009 at 03:13 AM.
BTW, buy several of them if you are attempting a repair yourself. Chances are you have another problem that is causing a short and burnt the resistor by overcurrent. Is that diode the magnetron diode? Is the resistor part of the magnetron circuit? I would be concerned with the voltage doubler circuit which includes a capacitor having a shorted component. If you are going anywhere near this stuff, please be careful and discharge the capacitor with insulated tools.
are you sure about the resistance? The info I have says the three bands that are together are the value and the one spaced away is the tolerance? I'm not saying you're wrong, just checking. I don't want to fry this thing. Thanks, Andy
Actually, no I'm not sure.Originally Posted by surfref32
First mistake I made was using an online calculator and plugging in the colors instead of doing the calculation myself. I didn't notice that an error message popped up because the colors I entered were an invalid combination. The default value on the calculator is what I offered earlier by mistake. It fooled me. I didn't even check. My apologies.
However, the 1st stripe in a 4 band resistor cannot be silver or gold. So, the resistor has to be read, on your photo, from right to left.
But, this is why it is important for you to verify the colors. I am seeing black, red, white, gold. This combination is invalid. white is 10 to the 9th power in that case. No way.
Please look closely and tell us what the colors are, in order. If the picture is not picking up another stripe, please detail it.
Again, my apologies for not catching my lazy mistake.
After taking the time to actually consider this instead of going on autopilot, I believe this is not a resistor. It is an inductor.
The first band must be grey. Is it not? It appeared silver or gold to me on my monitor.
This is the only way it makes sense, because if this were a resistor, the last band of a 4 band resistor can't be black. But black indicates +/-20% tolerance for an inductor, so it is valid.
Grey,white,red indicates 8.9 millihenries.
If this is the color combination you see, unless I am blind or crazy this must be correct.
I would not want to venture a guess about the power rating.
I had the same trouble with the colors and my eyes see the same things your's do. The board is marked R175 in that spot and I can only guess that means resistor number 175 on the board. The colors didn't make sense to me either. This thing got very hot as you can see so I can only assume that the heat changed the colors a bit from what they were originally. This is where experience comes in and that's something I don't have. The factory schematic would be nice but I have no clue where to find it. The board is a Whirlpool #4448877. There's a pic of a new one online but the resolution isn't good enough for me to ID the resistor.
Even though we haven't come to a conclusion yet, I want you to know that I appreciate you taking the time to check on this for me.
Edit, I hope this pic is a little better.
Last edited by surfref32; 4th December 2009 at 12:48 PM. Reason: add pic
That 1st band
Hi, the first colour band might have been brown . That will give you brown ,white , red ( 1.9 kΩ ). Not sure about the last band as a black does not add up for a resistor. What I do in a situation like this is to use a sharpie or file and file the resistor open. Then use my multimeter on the carbon track to try and make out what the resistance should be.
That is definitely a resistor and further supported by the fact that the PCB indicates it as R175. The band on the far end may be the TEMP Coefficient band as list in this chart:
Don't make me reach through this monitor to slap you a good one!
I will not explain electronic theory. For those who know, no explanation is necessary. For those who do not, no explanation is possible!
I hadn't even noticed that the resistor had a board label. Panning the picture out helped.
So, it has to be a resistor, but the colors don't make sense to me. Very confusing.
HiTech. I'm definately not arguing that this is a resistor for obvious reasons. But how what would you judge the value to be based on the "Violet Gives Willingly" rhyme? i.e the chart.
