Yes. The probe detects the switching activity of a power inductor, so the board must be live: battery connected or bench power supply, device attempting to boot. On an unpowered board no light comes on, and that's normal.
2+2 FREE TODAY | CircuitSenseā¢ - The dead inductor found in seconds!
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Specifications and what's in the box
| Type | Inductor activity probe for circuit boards, one button, one green light |
|---|---|
| Size | 3.5 Ć 1.4 in (88 Ć 36 mm), 1/4 in (6 mm) tip, about a third of an ounce: fits in a pocket |
| Power | 5 V via USB-C: charger, a PC's USB port or a power bank. No battery |
| Principle | Detects the switching activity of a power inductor on a powered board |
| Reading | Green light on: rail alive. Dark: open inductor or rail with no activity |
| Detection zone | About 1 inch (2 to 3 cm) around the tip; aim at the inductor, avoid shields and heatsinks |
| Compatible | Smartphones, tablets, laptops, game consoles, TVs, chargers, automotive ECUs |
| Limits | No ĀµH value, no capacitors, no diodes, and no direct short-circuit detection |
In the box
- ✔ 4 CircuitSenseā¢ probes (2 bought + 2 free)
USB-C cable not included: any USB-C cable you already have will do.
244
reviews
An iPhone that wouldn't turn on, two evenings with the multimeter for nothing. Board powered, probe in hand: the inductor with no activity showed up in thirty seconds. Replaced it, the phone booted. I gave two probes to my brother.
Max W.
- ✔The dead inductor found in seconds, no desoldering
- ✔The $39 to $80 for a repair shop diagnostic stays in your pocket
- ✔One button, one light: the multimeter waits its turn
- ✔Plug in via USB-C, no battery to replace
As seen in
Going viral on Pinterest with weekend repair hobbyists
Over 1.2 million views on the "motherboard won't turn on" videos. The 2+2 pack goes first, and stock is limited.
Know that moment?
The phone stays black. You know it's an inductor or a power rail. But which one?
🔌
Two evenings with the multimeter in diode mode, rail by rail: 15 to 30 minutes per board, readings that drift, and the doubt that's still there at the end.
💶
The repair shop charges $39 to $80 for the diagnostic, $80 to $200 for micro-soldering, and $450 to $600 for a replaced motherboard. Often for an inductor worth a few cents.
🔥
Swapping the wrong component: a part, an hour of soldering, $80 to $180 in labor if you have it done, and the fault still there.
It's not the method you're missing. It's the first pass that eats all the time.
Repair shop diagnostic: $39 to $80. Micro-soldering: $80 to $200. CircuitSenseā¢: $24.99 for 4 probes, reusable on every board you own.
The dead inductor shows up in seconds, not in two evenings
Board powered, tip near the inductor: green light, the rail is alive. Dark, you've found the fault. No desoldering, no multimeter.
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Triage in seconds
Every visible inductor checks in 2 to 5 seconds, instead of 15 to 30 minutes rail by rail.
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No desoldering
Nothing to remove, nothing to solder: the tip gets near the inductor and the light answers.
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Zero paid diagnostics
The $39 to $80 for a repair shop diagnostic stays in your pocket: the part is identified before you buy.
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USB-C, no battery
Plugs into a charger, a PC or a power bank. Nothing to recharge, nothing to replace.
The laptop won't turn on, and you no longer have to guess
Board powered, run the tip from inductor to inductor. The one that stays dark points to the dead rail. You know what to replace before you buy.
No more guesswork replacements that cost $80 to $180
A part swapped for nothing is a part, an hour of soldering and the doubt that remains. The light isolates the faulty rail before you heat the iron.
The multimeter stays in the drawer for the first pass
No more slipping probe tips or drifting readings. One button, one light, and you only pull out the multimeter to confirm.
What our customers notice
96%
located the dead rail in their very first session
94%
do the first pass without pulling out the multimeter
92%
avoided a paid diagnostic at a repair shop
One USB-C port, one button, one light
No settings, no calibration, nothing to desolder.
1
Plug in
Connect the probe to a charger, a PC or a power bank with a USB-C cable (5 V). Power the board under test: battery connected or bench power supply.
2
Hover
Button held down, bring the tip close to each power inductor, 2 to 5 seconds per inductor, away from metal shields and heatsinks.
3
Read
Green light: the rail is alive. Dark: open inductor or dead rail, that's where to look. Confirm with the multimeter before you solder.
CircuitSenseā¢ in our customers' hands
Photos sent with their reviews. Real workbenches, real kitchen tables, no studio.
CircuitSenseā¢ vs. a repair shop diagnostic or the multimeter alone
All three find the fault. Only one does it in seconds, at home, for under $25.
| Criteria | CircuitSense | Shop or multimeter |
|---|---|---|
| Price | ✔ $24.99 for 4 probes, reusable | ✘ $39 to $80 per diagnostic, $80 to $200 for micro-soldering |
| Time | ✔ 2 to 5 seconds per inductor | ✘ 15 to 30 min rail by rail, or days of waiting |
| Effort | ✔ Nothing to desolder | ✘ Shields removed, tips on every pad |
| Reading | ✔ Light green or dark | ✘ Drifting numbers to interpret |
| Where | ✔ On your bench or the kitchen table | ✘ Board handed over to a repair tech |
| Skill level | ✔ One button, no training | ✘ Schematic, diode mode, experience |
| Guarantee | ✔ 30 days money-back | ✘ Diagnostic billed, even with no repair |
What people hold against inductor testers, answered honestly
We read the 1- and 2-star reviews across the whole category. Here's what's behind each complaint, and how to avoid it at home.
"It said good when the board was dead."
The number one complaint, and it comes from a false expectation: the probe tests inductors, nothing else. A green light doesn't clear a shorted capacitor or a fried chip. Use it for the first pass, then confirm with the multimeter in diode mode.
"The light comes on anywhere."
Near a shield or a metal heatsink, yes: the detection zone is about an inch. Aim at the inductor itself, keep the tip away from metal, and compare inductor by inductor: the one that stays dark while its neighbors light up is the suspect.
"Nothing lights up, it's dead on arrival."
In most cases, the board under test wasn't powered. The probe reads switching activity: battery connected or bench supply, device attempting to boot. Probe plugged into 5 V, button held down. If it truly doesn't react on any powered board, write to us: it gets replaced.
"No manual, no cable in the box."
True, and we say so before you buy: the USB-C cable isn't included, your phone's will do. The manual is the "One USB-C port, one button, one light" section above, in plain English, with the three steps and the two traps to avoid.
30 days to find your first fault, or your money back
Plug in the probe and test the board that's been fighting you. If the light doesn't save you time, write to us within 30 days: we refund you in full.
CircuitSenseā¢ customer reviews
Verified reviews from our customers across the US and Canada
Anthony B.
Verified
iPhone 11 that wouldn't turn on. Board on the bench supply, four inductors green, the fifth dark: charging rail dead. Two hours of multimeter work avoided.
Thomas V.
Verified
Useful for motherboard troubleshooting, especially the power inductors. The board has to be powered, otherwise nothing lights up, which makes sense.
Cyril V.
Verified
Compact, fits in my mobile tech kit. The light responds right away, it triages the suspect boards before I pull out the heavy gear.
Mehdi N.
Verified
Faster than the multimeter for the first pass. Careful near metal shields, the light can come on: you have to aim at the inductor.
Nicholas R.
Verified
Speeds up my workflow: I confirm the state of the inductors in seconds. 4 stars because there's no USB-C cable in the box, luckily I had one.
Julian M.
Verified
Tested on a PC power supply: the open inductor found in under a minute. The green light stays clearly visible even under the bench lamp.
Hugo C.
Verified
One button and go, stable results after three months of daily use in the shop. Doesn't replace the multimeter for confirming, but what a time saver.
Aaron S.
Verified
Dead power line on a Samsung found in two passes, without desoldering a shield. The green-or-dark feedback is reassuring right away.
Sebastian K.
Verified
After several months in the shop: fast detection, stable readings, fewer parts swapped for nothing. Paid for itself on the first repair.
Oliver A.
Verified
Skeptical at first. I fixed a laptop charger and a console by spotting the inductor with no activity. You have to read the instructions once, then it just works.
Karim P.
Verified
Console that wouldn't boot: 3.3 V rail dark on the light, then a shorted capacitor found with the multimeter. The probe told me where to look.
Ethan Q.
Verified
Intermittent fault on an old amp found without tearing it all down: the inductor that went dark now and then. Perfect for weekend tinkering.
Mark L.
Verified
Four probes for this price: one in the shop, one in the case, two given to colleagues. They all respond the same.
Damian D.
Verified
Quick diagnostics on an automotive ECU and home appliances. Avoids guesswork and pointless replacements.
Fabian F.
Verified
Accuracy as promised once you understand the board has to be powered. The light stays readable in a dark corner of the shop.
Lawrence P.
Verified
For my on-site repairs: reliable spotting, without damaging fragile parts. Bring a power bank to power it.
Adrian T.
Verified
Handy in the shop: light on or off, nothing to interpret, ideal for triaging suspect inductors without taking everything apart.
Your questions before you order
Straight answers, including the ones we'd rather skip.
Does the board need to be powered?
Does the board need to be powered?
Green light on, what does that mean exactly?
Green light on, what does that mean exactly?
Green: switching activity is detected on that inductor, the rail is alive. Dark: no activity, so the inductor is open or the rail isn't starting. That's where to look, then confirm with the multimeter in diode mode.
Do I need to touch the inductor with the tip?
Do I need to touch the inductor with the tip?
Bring the tip close to or lightly touch the inductor, button held down. The detection zone is about 1 inch (2 to 3 cm) around the tip: aim at the inductor and stay clear of metal shields and heatsinks, which can trigger the light falsely.
Does it detect short circuits?
Does it detect short circuits?
Not directly. It shows you the rail that's no longer alive, which narrows the search to a few components. To find the shorted part, keep your multimeter in diode mode or your bench supply. The probe does the first pass, not the final word.
Is a USB-C cable included?
Is a USB-C cable included?
No. The probe plugs in via USB-C to any 5 V source: phone charger, a PC's USB port or a power bank. The USB-C cable you already have will do, no special adapter needed.
Which devices does it work on?
Which devices does it work on?
Any board with a switching power supply: smartphones, tablets, laptops, game consoles, TVs, chargers, power supplies and automotive ECUs. The gain is biggest when the inductors are visible, not hidden under a soldered shield.
Does it give the inductance value?
Does it give the inductance value?
No. It's a yes-or-no tester, not an LCR meter: it doesn't measure microhenries, capacitors or diodes. If you need the exact value of an inductor, you need an LCR meter. To find the fault fast, the probe is enough.
Does it replace the multimeter?
Does it replace the multimeter?
No, it complements it. The probe does the first pass in a few seconds per inductor, where diode mode rail by rail takes 15 to 30 minutes. Once the suspect rail is found, the multimeter confirms and pinpoints the component.
How many probes will I get?
How many probes will I get?
Four. The 2 + 2 offer ships two probes bought and two free for $24.99 instead of $49.98. One on the bench, one in the mobile kit, and two to keep aside or give to a colleague.
How do shipping and the guarantee work?
How do shipping and the guarantee work?
Shipping is free, insured and tracked: you get a tracking number by email as soon as it ships. If the probe doesn't save you time on your first fault, write to us within 30 days: full refund.
Today's offer: buy 2, get 2 free
Order today. Next dead board, you'll know where to look in seconds.
Four probes for $24.99 instead of $49.98, that's $6.25 a probe. The price goes back to $49.98 when the offer ends.
- ✔ Four probes: one per workstation, or to give away
- ✔ USB-C, no battery to replace
- ✔ 30 days money-back
Add the pack to your cart above before today's offer ends.
Heads up! Order before Thursday, 10/01/2026 to lock in the promotional offer.
