[SOLVED] Should I RMA my Seasonic M12ii PSU or buy a new PSU since my Seasonic M12ii failed on me?

Aug 8, 2019
Should I RMA my Seasonic M12ii PSU or buy a new PSU since my Seasonic M12ii failed on me? My Seasonic M12ii PSU is under warranty.

My system specs:

Ryzen 7 1700 didn't OC
16GB DDR4 2400mHz RAM
MSI Armor RX 570 8GB
Gigabyte DS3H B450M mATX Mobo
Seasonic M12ii 620 Watt PSU
1TB WD Blue Hard Drive
250GB Crucial MX300 SSD
4x120mm fans
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if it's still under warranty, do both - always good to have a spare, and the good-old S12 / M12 usually never disappoint...

Newegg has a pretty good sale going on with Rosewill Capstone series, the 650w is $70 which is really good price for a top-tier SuperFlower OEM unit.


Jun 13, 2015
RMAing is essentially turning in a faulty unit to the manufacture in exchange for a brand new, or almost brand new unit. RMAing is your best option. You can always buy a better quality unit, and still have the M12ii as a backup secondary PSU.
Looks like you're going down the "Why you shouldn't buy" rabbit hole - and will agree to a small extent, it is sad that is Seasonics budget answer to the new CX series with the Great Wall OEM is to use the old design in both these and the new S12iii lines. I do admit I largely prefer the CX for intel or if you want any sleep or hibernate modes, and that is more about the group regulation issue over the protection issue.

Regarding the protection issue, truth is I have a few S12ii/M12ii as well as several Antec NEO eco / earthwatts / HCG models still going in a few older rigs still running 24x7 to this very day in core2 / Athlon X2 and higher rigs. They are still reliable despite the lack of protections the better units provide, the few failures I have seen on them has never resulted in component damage that I can recall (suspect you will find exactly the same with yours). TL;DR not enough of an issue for me to allocate budget to go out and replace all these units. It's up to you to decide if it's worth the cost and hassle to have it shipped out for RMA replacement, I probably would.


Nov 3, 2019
I heard that the Seasonic M12ii PSU lacks modern protections like Over Current Protection (OCP) and Over Temperature Protection (OTP). Do I need those protections?
the main problem with the S12/M12II is how they perform in load transient response compared to modern PSU's , and this is not ideal for how modern gpu's work
OTP though it doesnt have.
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The M12-II is a single rail, group regulated psu. It generally doesn't require OCP because by the time that would kick in, the OVP would have long since tripped. The smaller 520w was tested and didn't fall out of spec on the +5v rail until it hit 584w output, not something many modern dc-dc units can do. The most worthwhile protection it does lack being OTP.

There's really only 2 issues with group regulated designs, the first being that the +5v rail is basically powered by the 12v rail, and in a majority 12v pc, that can cause issues, 1 rail load affecting the other. The other issue being lower power states like sleep modes, that mainly affects Intel Haswell or newer cpus, but can also affect Ryzens on Balanced power settings.

That and rated wattage is rarely close to what the 12v rail actually supplies, in a dc-dc psu they are very close, if not the same, by comparison the 520w M12-II is 480w 12v, and many are farther apart than that.
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