Can incorrect RAM blow a G4 PSU

[CTB]

I have a G4 Gigabit Ethernet and accidentally put 5v RAM into two of the slots. It booted however the power light went off after about 3 seconds and then I could smell smoke coming out of the PSU. I unplugged it, removed the RAM and rebooted. Same thing, Power light goes out after 3 seconds and I can still smell smoke.

Is the bad PSU just a coincidence or a result of the wrong RAM?

Have I likely done any more damage?

Will a B&W G3 PSU work as a replacement?

 

[waynestewart]

The G4 Gigabit Ethernet has more pins on it's connector than the G3 B&W.

 

[Byrd]

Whatever you've done probably isn't good, you might want to open up the PSU and inspect for damage, along with damage around RAM slots/nearby components.

The Gigabit PSU isn't an ATX standard but you can hobble up a harness from a standard ATX PSU:

ATXG4

 

[CTB]

I found another G4 in my collection with a lot more RAM than the one I was trying to upgrade anyway. So I might just out this one on the “maybe later” shelf.

 

[Unknown_K]

Isn't the RAM keyed?

 

[CTB]

No. The ram fitted fine. However when I checked after the “incident” the ones I installed were 5v instead of 3.3v

 

[Unknown_K]

Putting a 5V part into a 3.3V socket means it could still work at lower voltage or just not work assuming that the wiring for the RAM is the same (no idea). Putting a lower voltage part into a higher voltage socket lets out the magic smoke.

In the morning I will go look if the RAM is keyed the same (shouldnt be).

 

[CTB]

Exactly what I thought and then even with removing the EAM the PSU is still smoking. They system definitely doesn’t like it as the power light comes of for about 3 seconds and then turns off the whole the system still tries to boot with PSU smoking it’s head off.

 

[Phipli]

Sometimes the chips support both voltages, or even have voltage level shifting on the SIMM/DIMM. But 5V in 3.3V sockets is less bad than the other if mentioned.

Got a photo of the DIMM? To check the keys.

 

[CC_333]

Exactly what I thought and then even with removing the EAM the PSU is still smoking. They system definitely doesn’t like it as the power light comes of for about 3 seconds and then turns off the whole the system still tries to boot with PSU smoking it’s head off.

That's definitely not right!

Have you looked inside the PSU to ascertain where the smoke is emanating from?

It's possible that the PSU just coincidentally blew on its own (it's been known to happen), and would've done the same regardless of what RAM you installed, because putting RAM rated for 5V – assuming the pin out is otherwise the same – into a 3.3V slot shouldn't blow things up! The worst outcome should be simply that it doesn't work.

c

 

[CTB]

That was my original question in the thread. I had come to the same conclusion, how could RAM with higher voltage break something rather than it just not work? The only answer was that is was coincidence that the PSU blew at the same time I opened the machine to put the RAM in.

 

[AndiS]

Maybe, just maybe the RAM sucked that little more current to push the PSU over the edge.

It's a possibility but more likely it was just a coincidence. 5V RAM in a 3.3V socket should not break anything otherwise.

 

[CTB]

That makes me feel better that a “coincidence” was possible. I just realised I had also been stressing the PSU out earlier with a new SSD-IDE drive copying off the original ATA hard drive. Maybe a combination of both sucked a little too much for it to handle.

 

[cheesestraws]

Yeah, I suspect this is a marginal PSU that would have gone when you did anything to the machine at all: the fact that the RAM was wrong is probably coincidental.

 

[CC_333]

This reminds me of a time when I had built a PC for myself during summer 2008, and I had paid something like $50 to a local shop for a PSU to install into it because the one I had been using belonged somewhere else.

Anyway, it worked fine for awhile, and then I went to turn it on one day, and I heard a pop, then smelled a slight whiff of smoke.

Fortunately, it didn't take anything out with it, but that was a big waste of $50, considering I have PSUs I bought for half as much off NewEgg from around that time that, to my knowledge, are still working to this day.

c

 

[Unknown_K]

Cheap power supplies can be crap. I used to buy some PS from a defunct company called ComputerGeeks. One of the supplies was supposed to be for gamers and was 880W which was more than what I needed. Well I connected it to a dual Opteron system with a Radeon HD 4870x2 card which was a power hog back in the day but would be power efficient these days. I ran 3DMark Vantage for some benchmarks and halfway into it I hear a big boom and the machine shut down. Voltage regulators in the supply blew but oddly enough the rest of the machine was fine and still works today.

These days I still with brand name supplies.