COOLMAX CX-400B 400W ATX v2.01 Power Supply

Pros: Coolmax has been "updating" this model of PSU, but mostly downgrading it further. It does have some pros though...barely. It uses a nice quality fan, and even though it's wired straight to the 12V all the time (No thermal fan control whatsoever) it stays quiet, and the bearing has plenty of grease so it shouldn't fail. The older revision of this PSU used the infamous two transistor circuit for the +5VSB, which wasted a lot of electricity and killed lots of motherboards. They updated it with an 8 pin IC to generate the +5VSB which is a lot more efficient and isn't prone to frying your motherboard.

Cons: Everything else... The old revision (Circa 2009) could pump out about 350W, this one is capable of about 275W (With a very mixed rail load). It claims two 12V rails capable of 348W. HA! It only has one rail, and it uses a 16A ultra fast rectifier. Since the fan runs fast keeping it cool, I bet it could do the full 16A, but that's only 192W...Almost 90% of your computer uses the 12V. That makes this basically a 200W PSU in a modern system. And if you load it up, that 12V rail is going to sag quite a bit...

Overall Review: Don't give these guys your money, they don't deserve it.

Pros: This power supply looks good. It has a nice black finish and large fan. I like the air outlet grill on the back. Plenty of power connectors. Provides voltage within +/-0.5v on all channels and passed our high current load testing. Those that don't develop problems work well for up to or over 2 years.

Cons: We have built over 20 computers with this power supply and about three (15%) of them developed the same problem. They would randomly turn themselves off (latch). The problem started to show after a few months (customer support call records show this) and the problem got worse. If the problem starts it only lasts about 1 year or less. RMA if this PSU starts to latch on you.

Overall Review: If you have this power supply there are a few things you can do to improve the life expectancy. Use the current provided. I beleive the voltage regulation circuits become over sensitive or the power supply cannot maintain voltage at low currents. One PSU worked fine with extra DVD-ROM drives connected but if they were removed it would latch in less than one minute. Also keep it cool, set the fan on High instead of Auto or Low. This problem is worsened by >25C ambient temp. We have swapped to Rosewill PSUs for our custom builds.

Pros: Is quiet. Provides good power. Inexpensive.

Cons: Coolmax has to have the worst quality control ever. I have RMA'ed back 2 of these power supplies already (first one cooked after 3 months, second one the fan was banging and broke within first 10 minutes of installation) and I am about to RMA the 3rd one they sent me because as I opened the shrink-wrapped box, I looked and the wire ends of two of the runs are exposed...as in not even in thier respective connectors (they didn't crimp them well enough). Absolutely unbelievable!

Overall Review: I have built many machines and have NEVER had this sort of problem (3 bad items in a row). I can easily accept one with a problem, heck, it happens. Maybe even 2, but I'd be getting leary by then, but now getting 3 in a row? Unacceptable!

Pros: Quiet

Cons: Power supply failed after less than 2 years of service. The 5 volt standby curcuit in the power supply stopped working,unable to start the computer.

Overall Review: Instead of spending an extra $xx for the extended warranty, buy a better quality power supply. I salvaged the cooling fan out of the power supply

Pros: Low price, looks nice, and it powers the computer.

Cons: Not silent. VERY cheaply built - metal casing and connectors feel flimsy. Too many Molex connectors and not enough SATA connectors. One of the Molex connectors wouldn't fit on the optical drive, but I tried another one and it fit fine. One of the SATA connectors (of which there are only 2) broke when I connected it to the HDD. Used the other one and it was fine.

Overall Review: The only reason I bought this PSU to begin with was because of the mail-in rebate. I would not buy it again.

Pros: Plenty of cables for a socket 754 board. Seemed to run fine for ages. It seemed to run a bit hot.

Cons: Died after 2 years. Began resisting the initial power-on. Eventually died while running and took my 6600GT with it. I don't think it was a surge.

Overall Review: My CX-350 recently died, too, which I bought a year earlier. It did not take any hardware with it. Buying all other brand PSUs these days. Buying an inexpensive PSU is _not_ worth it. I spent easily the $50 I saved not getting a $100 PSU on replacing parts on the failed box to see what was causing it to BSoD; and that was after replacing the dead PSU! 100% stable before the CoolMax died.

Pros: works well and is not loud

Cons: since i was replacing an old powersupply i had a little bit of trouble with connecting the power to the DVD Drive. the cable was to short so i had to move my dvd into one of the lower slots in order for it to reach

Pros: It keeps a computer in a den that stays warm running all the time. I replaced a stock power supply with this one. I updated the video card and moved the computer into the den which is only cooled when someone is in there, thus it rebooted inseasently w/o notice for a while. It now runs cool as a cucumber and no power spikes or lulls.

Cons: None.