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My vacuum cleaner has a motorised brush head that's just packed in. I've taken it apart and found what I think is the problem part. The part labelled 'F1' on the silkscreen, so presumably a fuse, has about 400kΩ of resistance. The markings on it read "15A 4T3. 1" which sounds pretty similar to a typical fuse spec. Only problem is, I can't find a fuse that looks like this online.

Is this indeed a fuse? If so, am I good to order any 15A, slow blow, through hole fuse? If not, what is it?

(I apologise for the quality of the below images, my camera was refusing to focus. Also, I have since cleaned the PCB from all the muck that may have caused problems.) picture of PCB picture of PCB

EDIT: I've found this page online. The listing seems to have similar writing to the markings on the part, but the picture looks more like a typical fuse. Does anyone reckon this is a similar enough listing that I can put the specs through the part search on a more convenient supplier?

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    \$\begingroup\$ ”has about 400kΩ of resistance” That’s a blown fuse. \$\endgroup\$
    – winny
    Commented Jan 1, 2023 at 14:31
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    \$\begingroup\$ Do you have any idea why the fuse blew? Also, make sure that the voltage rating of the replacement is sufficient. \$\endgroup\$
    – Andrew Morton
    Commented Jan 1, 2023 at 14:34
  • \$\begingroup\$ This motorised head receives power from some connectors built into the hose on the cleaner. I suspect I caused a surge by disconnecting/connecting this part while the cleaner was on (just quickly clearing a blockage). \$\endgroup\$
    – MrMeowMeow
    Commented Jan 1, 2023 at 14:41
  • \$\begingroup\$ I wonder, and it is only wondering, if 4T3 represents the I²T value for the fuse, in the fashion of 4K7 for a resistance value. \$\endgroup\$
    – Andrew Morton
    Commented Jan 1, 2023 at 14:52
  • \$\begingroup\$ I figured T was for 'time' which usually denotes a slow blow fuse, but not entirely sure \$\endgroup\$
    – MrMeowMeow
    Commented Jan 1, 2023 at 15:18

1 Answer 1

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The fuse in question is probably a glass or ceramic fuse with shrink wrap over it. Something like this:

enter image description here

If you cut the shrink wrap off there should be more informative markings on the fuse end caps or body.

Replacing the fuse (which should only be done with the exact equivalent) could possibly fix the issue, but it's also possible or likely that something else has failed in order to make the fuse blow. If you replace the fuse with something that's not equivalent even more damage may result if the latter is true.

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    \$\begingroup\$ Amazing how I was so zoomed into the writing on the wrap that I hadn't even realised that's just shrink wrap, how embarassing! :D I'll give that a shot, cheers. \$\endgroup\$
    – MrMeowMeow
    Commented Jan 1, 2023 at 15:55
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    \$\begingroup\$ Yes, now I’m curious! \$\endgroup\$
    – Old Uncle Ho
    Commented Jan 2, 2023 at 13:04
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    \$\begingroup\$ Apologies for the delay everyone, took a moment to get round to opening it up! As predicted by @AndrewMorton, looks much more like a normal fuse underneath. The markings read "4T T3.15A250V" which I understand to be a slow-blow fuse, rated at 3.15A / 250V. \$\endgroup\$
    – MrMeowMeow
    Commented Jan 2, 2023 at 15:59
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    \$\begingroup\$ @MrMeowMeow Ah! 3.15 A is more reasonable than 15 A! You might want to edit your question to append that you removed the heatshrink and found the correct rating. (And it was Spehro, not me, who noticed it looked like heatshrink.) \$\endgroup\$
    – Andrew Morton
    Commented Jan 2, 2023 at 16:03
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    \$\begingroup\$ @SpehroPefhany I guess they print the markings all down a tube of heatshrink and then cut it "wherever". Or the machine was just having a bad day. \$\endgroup\$
    – hobbs
    Commented Jan 2, 2023 at 19:27

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