Hard to read resistor value.

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Guitbox

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Hello,

I'm fixing a Nuwave Induction Cooktop. It blew a fuse, which I replaced. Then, when plugging in, it made a pop and dimmed the overhead lights, and now gives me an error message.

I looked closer and see a resistor (and a transistor) that look toast. But I can't make out the resistor value. Anyone care to make a guess?




 

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It was a fast blow, 15 amp 250 volt glass fuse. When I replaced the fuse and plugged it in, the overhead lights on the same circuit dimmed and I heard a pop. (This unit goes into standby when plugged in, so it draws power immediately. But this was an excessive power draw.) The new fuse is still ok right now.
 
first digit looks like a 4, second digit in one pic looks like a 7 third digit definitely a 1... 47 and a multiplier of 1 is a 470 ohm resistor (multiplier basically= how many "0"s to add). if it's still drawing excessive current, there's more than this resistor and a transistor shorted.
 
starLED said:
I think it's 4701, which is 4700 ohms.
Click to expand...
i doubt they're using a 0.5% tolerance part (or even a 1% for that matter) in an appliance.... 2% tolerance (or better) are very rare in consumer electronics. 470 only appears in the E192 series... for a 1% tolerance part (E96 series) the closest values are 464 and 475 (which with a multiplier would read 4641 or 4751. for a reference and explanation of the numbering system go here: https://www.electronics-notes.com/a...tor-values-e-series-e3-e6-e12-e24-e48-e96.php
 

I think you've had a massive senior moment unclejed? (or I have?), 47 is a standard E12 value so available in all tolerances.
 
here's the E96 chart.... if it were there it would be "4.70" but it's not.... the 1% decade, being 3 digits instead of 2 has a different series of values in it's decade.
yes the two digit series all have 47 in them, but 4.70 is not in the 3 digit E48 or E96 decades, but does return in the E192 decade (for 0.5% or better tolerances)
E96 STANDARD RESISTOR SERIES
1.001.021.05
1.071.101.13
1.151.181.21
1.241.271.30
1.331.371.40
1.431.471.50
1.541,581.62
1.651.691.74
1.781.821.87
1.911.962.00
2.052.102.16
2.212.262.32
2.372.432.49
2.552.612.67
2.742.802.87
2.943.013.09
3.163.243.32
3.403.483.57
3.653.743.83
3.924.024.12
4.224.324.42
4.534.644.75
4.874.995.11
5.235.365.49
5.625.765.90
6.046.196.34
6.496.656,81
6.987.157.32
7.507.687.87
8.068.258.45
8.668.879.09
9.319.539.76
 
RS list 23 4K7 1% through hole resistors and 129 SM versions.

I suspect your list is essentially only the EXTRA ones above those in the lower ranges.
 
interesting... there seems to be a discrepancy between the value tables, and what gets manufactured.... when i worked for a prototyping company, an engineer for one of our customers specified RN55D 1% resistors with a value of 499 ohms.... these were used for TTL pullups... he ordered them specifically because he was color blind and needed to be able to read the digits on the resistors...
 
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