Mechanic short killer vc04 seems dangerous - Page 1
Forum section: electronics / beginners

author: psxpetey1
author_rank: Regular Contributor
timestamp: July 25, 2023, 08:12:59 pm
content: I just bought one of these and recently used it. After maybe 1 minute of use it shorted out. Lol 😆 the short killer short killed itself. Now I took the ends off and this thing does NOT look safe to be delivering more than a couple amps for a few seconds. The wires definitely shouldn’t be carrying 25amps at anytime at all. In order to remove it from its case I’d have to desolder some things which I am not anxious to do as it’s still charged up. I’m currently in the return processBut I’m wondering if anyone’s done I tear down of one of these things or knows how to discharge it without burning my house down.I am quite curious what component it burnt out so fast tho especially because it claims 25amps ya maybe at 0.0000000000000000001v lol 😂.Anyway if people have any experience with these let me know YouTube got absolutely attacked by showcases but I haven’t seen any tear downs of the gear itself.

author: Veteran68
author_rank: Frequent Contributor
timestamp: July 25, 2023, 08:34:33 pm
content: Not sure, but I'd just say these short finders always seemed gimmicky to me. I would expect any half way serious electronics bench to have a bench PSU (preferably linear) with constant current/voltage control. Even a cheap one. All a short finder/killer is is a power supply used to inject voltage with a current limit while showing the voltage drop and current consumed by the DUT. Almost any adjustable bench PSU should do the same thing. And it would be far more robust than these little SMPS units.I follow a repair guy that runs a Discord server, and he recently went on a rant about people discussing these short finders. It made him irrationally angry for some reason, and he added a rule that discussion of them is now prohibited on his server, lol.Sounds like you might need a short killer to diagnose your short killer?

author: Benta
author_rank: Super Contributor
timestamp: July 25, 2023, 08:39:32 pm
content: That gadget is a joke. But OK, you're $50 lighter, and the seller is laughing on the way to the bank.

author: psxpetey1
author_rank: Regular Contributor
timestamp: July 25, 2023, 08:45:48 pm
content: He probably shouldn’t ban it tho the only way you can expose bad/ scammy ideas is by talking about them. I do have a psu but I’ve always been curious about these because like you said they seem scammy. The scam seems to have come from India. All it is, is 2 batteries like you said with a wimpy motherboard inside with components (from what I can see) THAT CAN ABSOLUTELY NOT DO THE JOB. From what I can see from the side it looks very dangerous and poorly made I have seen better ones like the grey model.Seems like they are made from stripped out old laptop parts with a small machined metal case. Definitely can’t deliver 25amps tho mine maxed out at 4 and that was only for a few seconds.

author: Veteran68
author_rank: Frequent Contributor
timestamp: July 25, 2023, 09:01:14 pm
content: NorthridgeFix is another YouTuber I watch that uses these. Granted the one he uses (and shills, as he sells it from his online store) seems better built than this one, but he has a perfectly good Rigol bench PS across his desk. He said something once about preferring the short finder to the Rigol, but he'd also just blown one of the outputs on the Rigol somehow and wasn't using it anymore. I expect he "prefers" it more to push his high margin sales on the thing since he can't or doesn't sell Rigol gear.Personally, I'd reach for the bench PS everytime.

author: psxpetey1
author_rank: Regular Contributor
timestamp: July 25, 2023, 09:08:48 pm
content: I’ve watched him for a couple years now. Past the time where he advertised it that he was selling it I’ve seen him use it maybe once I doubt he uses it tbh but he does have a constant supply if they break lmao. I think I’m going to desolder mine and get the board out and see what broke.you can’t take the motherboard without desoldering the switches on the face plate it’s pretty ridiculous.

author: psxpetey1
author_rank: Regular Contributor
timestamp: July 25, 2023, 09:38:08 pm
content: Bodge city as suspected

author: psxpetey1
author_rank: Regular Contributor
timestamp: July 25, 2023, 09:43:27 pm
content: I assume they are using the case as ground with the big screw switches howtokillsomeone.com also very strange they are just using a resistor labelled r500 to keep things from grounding out which is only good for up to 2watts there is one 101 labelled fuse have yet to look up what that’s rated for but holy lord this device is a complete scam and a death/fire hazard.

author: coppercone2
author_rank: Super Contributor
timestamp: July 25, 2023, 09:49:40 pm
content: if you want a short killer just use a car battery its safer. Like just tap it on the terminals, possibly through a resistor.Why? Because a lead acid battery is designed to crank and is short circuit resistant. A lithium battery is supposed to be current limited. Even a power tool battery is likely not going to have a load impedance of shorted copper, the motor is substantial in comparison IMO.

author: psxpetey1
author_rank: Regular Contributor
timestamp: July 25, 2023, 09:52:56 pm
content: Really tho jesus luckily they can’t keep the money the return policy is still in affect I think I’m gonna make a couple YouTube videos on this because this thing is super unsafe and could definitely hurt someone and or burn their. House down. I’ll have to show it to north ridge as well he should not be selling these.

author: Veteran68
author_rank: Frequent Contributor
timestamp: July 25, 2023, 10:53:09 pm
content: Quote from: psxpetey1 on July 25, 2023, 09:52:56 pmHe doesn't sell that one (anymore). He sellsthis onenow. For $119, wow.

author: psxpetey1
author_rank: Regular Contributor
timestamp: July 25, 2023, 11:01:31 pm
content: https://northridgefix.com/product/mechanic-short-circuit-finder-detector-voltage-injection-power-supply-battery-operated/Still on his website. He’s always out of stock on everything god knows why he must have really small orders or something. Both the one you linked and the one I linked are out of stock as usual tho. That one looks a little nicer for sure no idea why the alligator clip is so large tho hard to use on small devices when they are so big.Hopefully that one’s better than this peice of trash.

author: Veteran68
author_rank: Frequent Contributor
timestamp: July 25, 2023, 11:16:50 pm
content: Yeah he doesn't always remove old devices from his store but I don't think he's sold that Mechanic model since he got the new one, especially since he's had this one white labeled as a NorthridgeFix (NF) brand (which he's doing with a lot of his gear now). I think he talked about it in a video awhile ago that this new one replaced that old one and was so much better. And Ihaveseen him use this new one in several videos, it just seems obvious to me he's trying to push something with obviously a pretty high markup over recommending a proper bench PSU. And the sad thing is I think he does get a lot of customers -- this and many of his other overpriced tools come in and out of stock very often. His microscope, for example: $700 for a run of the mill Chinese HDMI microscope with 180x lens and a couple of Barlows, but no light ($90 extra) and no stand ($400 extra). Really? I can buy an AmScope trinoc scope with double boom stand, HDMI camera, and ring light for what he charges for just the base camera and lens. Heck you can pick up a 30v/5a Tekpower linear bench PS for less than he charges for this short finder and have far more functionality out of it. Yet he regularly runs out of stock of both. And no way he's just getting 3-4 of these at a time with his custom branding. I've seen his videos where he shows these stocked by the case. People really do buy his stuff.

author: --Oz--
author_rank: Regular Contributor
timestamp: September 22, 2025, 12:13:04 am
content: Quote from: coppercone2 on July 25, 2023, 09:49:40 pmThat is the worst advice I have read on EEV.

author: Buriedcode
author_rank: Super Contributor
timestamp: September 22, 2025, 06:25:01 am
content: I suddenly feel old .. I can't be the only one who has never used more than 1amp at 0.4V to find a short? Why the need for such high current? Is it to "blast" the shorts out? - which is frankly not something you should be doing around electronics.

author: tszaboo
author_rank: Super Contributor
timestamp: September 22, 2025, 09:41:58 am
content: Quote from: Buriedcode on September 22, 2025, 06:25:01 amThere is a community of people, who watch laptop repair videos, and try to learn electronics that way.The general consensus is that engineers are idiots, because MOSFETs always blow up. Certain brands are better or worse because some guy uploaded videos and he had to repair like 3 of them. There seems to be an entire category of repair tools geared towards these people. Yes, this is definitely a tool to "blow up" the short, usually a bad idea. I've seen this demonstrated only once where it was useful, but that was in the time where PCB etching was still an issue, and you could "repair" a board by blowing microscopic shorts up.

author: mikerj
author_rank: Super Contributor
timestamp: September 22, 2025, 02:46:18 pm
content: Quote from: Veteran68 on July 25, 2023, 10:53:09 pmQuote from: northridgefixIf a bench supply can't handle a short circuit without blowing up it has no business being called a bench supply.