I’ve stumbled upon this forum in a search for a replacement part for a PCB that makes up a digital ballast for a HPS light used in basil clone production.

I’m handay with a soldering iron but I am no electrical engineer so I’m finding it hard finding a way to source the replacement part.

From what I’ve gathered it’s a slow blow fuse, 10a / 350v as stated in the picture below. The ‘F1’ led me to believe it’s a fuse... (I know, a true amateur) ha!

Is this a speciality piece? I’m in the UK and which is 230/240v supply. With the ballast rated to 1200w I believe the 350v is to fascilitate the inrush of current... (excuse me if terms are spaghetti).

Any ideas on how to identify this component? You can see in the pic it has burnt out / blown and there’s also evident of a bit of water damage isolated to this fuse and the incoming L and N terminals.

Can I replace the fuse?

blown PCB fuse

  • \$\begingroup\$ Here’s a photo of the part I’m trying to source! I found text and what looks like a logo on the underside... ibb.co/QnVT7XM \$\endgroup\$
    – PCBSteve
    Commented Oct 24, 2019 at 15:41

1 Answer 1


You are correct, it is a fuse.

You could potentially replace it with another 10A/350V fuse. The problem with doing so is the timing of the fuse is not known, which could be a problem with inrush current. When I have found myself in this situation, and the inrush current is not known (because I was in a hurry), I started with fast blow fuses and worked my way to slow blow (but that was also with replaceable fuses).

The best thing to do would be to find a BOM (Bill Of Materials, with all the parts and manufacturers listed on it) to find a direct replacement, if that can't be done, then experiment.

Another note: The inconsistency in the circuit could still exist, so even if this is repaired the fuse might fail again.

  • \$\begingroup\$ Thanks for the response! The terms are good to know so I’ll ask the manufacturer for this information. I hear you on the circuit still potentially having other problems - this is one I’ll attempt because visually it looks like it could be the cause, of more work required I’ll retire it to practicing desoldering! \$\endgroup\$
    – PCBSteve
    Commented Oct 22, 2019 at 18:03
  • \$\begingroup\$ Your welcome, if you consider the answer as answered, then mark as such (or wait for more) \$\endgroup\$
    – Voltage Spike
    Commented Oct 22, 2019 at 18:07
  • 1
    \$\begingroup\$ If you're in the UK, Farnell (just Google it) should have the part. Little through-hole fuses like that are pretty common. The manufacturer won't talk to you unless you're buying a thousand at a time, and even then you'll be small beans; your best bet is to get a selection of speeds at the 10A/350V rating and experiment. \$\endgroup\$
    – TimWescott
    Commented Oct 22, 2019 at 20:24

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