r/pcmasterrace • u/Front_Cookie_1198 • 1d ago

Hardware PSU fails dramatically

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447

u/maxwells_daemon_ Ryzen 7 5800X, RX6600, 16GB (Arch, btw) 1d ago

Seems suspiciously like a PSU set to 110v and plugged into 220v

136

u/Busy-Distribution-45 1d ago

Was going to say, last time I saw something like that was when I thought a power supply was auto-switching and plugged it into a customer’s machine. Turns out it was manual, and had been on 110 power as we are in the US (industrial machine was stepped up to 220).

58

u/Krell356 22h ago

What kind of trash PSU explodes into flame over that though? Every one ive ever seen blow from that just makes a loud pop and starts breathing the mysterious blue smoke of death.

4

u/falcrist2 7h ago

the mysterious blue smoke of death.

It's called "magic smoke", and there's a whole wikipedia page about it.

10

u/Busy-Distribution-45 22h ago

The flames were very short lived and it looked like it was the label or case that actually caught. When it happened to me, the caps (I assume it was them, anyway) exploded sequentially and sounded like a Chinese firecracker string going off, but louder, and there was like thick black smoke that smoked out the lab. As for if there were flames, well, it was inside the pc case, so there probably were, just we couldn’t see them.

7

u/TheRealFakeWannabe 18h ago

bro but what kind of trash PSU explodes into flames over getting plugged?

2

u/FoxyBastard 17h ago

Back in about 2001, I got handed a shitty comp with a switch on the back to switch between 220v and 110v.

Here in 220v-land in Europe.

I wrote the PC off as a write-off (from the 80s, probably).

I couldn't help but to hit that switch while it was running and see what happened.

A pop, and a puff of smoke.

Killed the machine.

1

u/the_harakiwi 5800X3D 64GB Noctua 5080 18h ago

When I did that to a PSU it made a loud

POP

and a bit of magic smoke but no fire. This was before auto switch PSUs.

1

u/NoConfusion9490 5h ago

Usually they just don't operate at the wrong voltage. Maybe they source unpredictable DC to the other components and do damage, but they should NEVER do this.

1

u/Busy-Distribution-45 2h ago

If you put a manual switched one on 220v when it is switched to 110, it does more than not work. The other way around, yes, it just doesn’t turn on, but double the voltage causes issues unless you get one they bothered to put fuses in

1

u/NoConfusion9490 36m ago

I've done that plenty of times and the built in protection circuit handled it fine. Just an LED blink code.

104

u/Nyakuru Hello my computer has virus 23h ago

I don't think that's the case. The PSU (VSP Megamax) doesn't have the voltage switch as it has active pfc. In fact, most PSUs can adjust the voltage accordingly.

80

u/sanYtheFox 23h ago

Yea, i haven't seen a voltage switch on a PSU for at least 15 years, maybe even longer.

35

u/Emu1981 23h ago

In fact, most PSUs can adjust the voltage accordingly.

Plenty of cheap PSUs that don't have active PFC and require you to set the 110v/220v switch properly. That said, they are becoming rare enough that it isn't something that you would think to check these days...

13

u/reddithooknitup Asus Rampage VI Extreme 23h ago

You are right, now imagine that's the part that failed.

3

u/Ordolph 7700X, RTX4080 22h ago

Also, if that ACTUALLY happened with PSUs just because the switch was in the wrong position, it would be a pretty big and easy-to-win lawsuit. A minor user error should not result in an electronic device catastrophically exploding.

2

u/SoulWager 22h ago

I don't think it has active PFC, it's just a 240v only model.

26

u/Toraadoraa 23h ago

My thought too! But when's the last time you saw a black modern PSU with a voltage selector? Most now are auto ranging.

3

u/OmegaAngelo 23h ago

Idk all the micrometer ones are manual, and I had one explode the other day when it was plugged into a 220 step up outlet by accident

2

u/Toraadoraa 23h ago

Oops! I hope it wasn't an expensive

3

u/willstr1 22h ago

Might be a super cheap one? Not a computer power supply but the power supply for my 3D printer had a manual voltage selector (and they made quite a point in the manual and setup instructions to make sure you set it correctly)

15

u/Repulsive-Clothes-97 RTX 5080| R9 5900x| 64GB 3200 22h ago

That PSU is the Megamax VS750D, it does not have a 120-240 switch, the label says it operates 180-240.

120-240 switches are mostly a thing of the past.

2

u/RincewindTVD i7-12700 20h ago

I went to check, and yeah 180-240. 180? what. Who uses 180?

1

u/MelangeBot 15h ago edited 15h ago

Nobody but that's not the point. The range tells you that under 180v it does nothing, and above 240v it might blow up.

It's probably a variant of their powersupply that is only sold to markets that are 220v or 240v like the European market and not to the US. It makes sense to save a bit of money on building them because appart from North-America and some countries in middle and south, all other countries use 220v-240v

Especially now that with the high shipping fees and tarrifs there ain't much money to be made selling to the USA anyways.

3

u/Ithuraen 23h ago

I've seen that happen from about 15cm away. There was a loud bang, blue smoke, and me on my arse as a class full of students peered through the door to see if I was dead. 

No flame though, maybe it was the lower wattage. 

9

u/LocalBeaver 22h ago

Dude it’s not the early 90s anymore.

-1

u/TaxHazyShade 20h ago

well, stupidity lives on forever ... OP is testing PSU's in his bare feet instead of at least wearing rubber-soled shoes ...

5

u/ItsSpaghettiLee2112 23h ago

Do PC PSU's not come equipped with fuses?

3

u/Zaffox_ 21h ago

They should. And it should have blown

2

u/RedShift9 14h ago

Fuses protect against overcurrent, not overvoltage.

1

u/NumNumLobster 17h ago

That would add like 23 cents to production costs though

2

u/Exotic_Fortune5702 23h ago

Look like a capacitor fail for me

2

u/HaydnH 21h ago

I worked for a major US hardware company back in the 90s, but in a 240v country. Every PSU that arrived was delivered with the voltage selector switch set to 110v... Sooo many pops happened.

4

u/GenXWaster 23h ago

Many, many years ago I worked in the burn-in dept for a PC manufacturer here in the UK who exported PCs to the US and Japan. The assembly line would load up 10 PCs onto a trolley which had all the leads necessary and a KVM. The trolley had a switch for 115V and 230V and 2 power leads. One, a standard BS1363 UK plug and the other was an IEC660309 which plugged in to a special mains run.

When the trolley came to us, we would look at the inventory slips which were in orange sleeves for 115V devices so you would flick the switch to 115V before you did anything more.

Young me, on 2 occasions, did this but then plugged the UK plug in and started switching everything on. Nothing happened. So then I reach over and turn the switch to 230V. Everything goes bang. The whole factory is aware that someone fucked up.

Point of the story, this video ain't that.

2

u/red286 22h ago

If you set your PSU to 110V and plug it into 220V, it should just trip the OVP and fail, not explode and catch fire.

1

u/Ziegelphilie 22h ago

Nahh I've done that, they just do a loud bang and they're done. This is straight up arcing, I wouldn't be surprised if a large capacitor or something had a loose leg

1

u/Adezar 22h ago

I remember that period of time when you had to flip a switch. I saw so many power supplies go boom/spark/smoke.

That transitional period of time was an interesting time.

Specifically during the early dotcom days when computer rooms/data centers started moving to 240 in the US. IT people would plug in new machines without verifying the setting and this type of light show was quite common because when you ordered systems in the US they shipped defaulted to 120.

1

u/house343 22h ago

Most are capable of both these days. 

1

u/TerribleBottle6847 21h ago

I remember this. We plug a 110v Playstation 2 to a 220v wall plug. It exploded like in the video. The PSU was the only one that was harmed.

1

u/Miiohau 21h ago

In that case it should have shipped from the factory set to 220v. Better it under powered than cause a fire.

1

u/IAmWeary 21h ago

Virtually any modern PSU can handle both automatically.

1

u/SelmaFudd 20h ago

Yep, about 35 years ago I flipped one of these switches while it was plugged in and sparks blew everywhere. Never fucked with a voltage switch again

1

u/Cool_Ad_9745 20h ago

I did that, but it didn't end up like this one. It just smoke and boogshhh.

1

u/jonnyGURUgerow 17h ago

PSU has not 110V support. It's so cheap it only supports high line.

1

u/Marty_McFlay 16h ago

I plugged a T1 switch into 220 once. it was actually super anticlimactic. one cap in the PSU popped and it made a little smoke and nothing else happened. My lesson that day (other than to always check voltage in customer demarc rooms going forward) was that power supplies made by reputable manufacturers, and purchased from reputable vendors, have tons of safety features built in as part of being UL Listed (or equivalent) and if we had been using an amazon special mystery chinese power supply that day might have been much worse.

1

u/NuSurfer 15h ago

Didn't know that was still a thing, like, since 2005 the power supplies I worked on in industry (consumer and commercial) were auto-ranging, rated 100-240V ac, 50/60Hz; all you change is the cord set provided with the pc.

1

u/alkor86 2h ago

I did this once. I'll never do it again.

1

u/ShiddyFardyPardy 23h ago

Yep, they used to have a switch, and Hoo boy when some kid came in and flipped it.....

0

u/AKA-Pseudonym 1d ago

That was my first thought, but I've never seen it do anything quite that dramatic

0

u/ZeroCleah 22h ago

You wouldn't be able to do that without an adapter or modified cord

0

u/FlatwormAltruistic 7h ago

You haven't switched PSU to 110V when it is plugged in to 220V from your post.

It doesn't do that if you were to switch it. I did when I was a kid. Fuse blew, had to reset it, PSU was fine.

OP PSU has most likely some protection mechanisms and insulation missing and it was just shorting out and since missing various protection mechanisms, then they didn't trigger.