Strange power problem

[IBDoomed]

<FONT face=Verdana size=1>I'm having a strange power problem similar to </FONT><FONT face=Verdana color=#000080 size=1>punkemon1</FONT>'s in this thread but not quite the same:<a href="http://forums.anandtech.com/messageview.cfm?catid=32&threadid=836209">

http://forums.anandtech.com/messageview.cfm?catid=32&threadid=836209</A>

My PC is in our bedroom and quite loud so the wife makes me shut it down at night. During the middle of the night I awoke to that all too familiar smell of a burning power supply. I assumed it was another pc in the room that was running at the time (my server) and immediately shut it off and went back to sleep. The following morning I start diagnostics on the server and it powers up and tests out fine. Not thinking it was my game PC since it was off at the time but low and behold it was. That 350w PS is completely dead.

I grab a brand new Enermax 300w PS I happen to have and throw it in. It works fine except that it won't power all my drives, I figures since it's 50w smaller than the dead one. So I go buy an Antec 400w today. I plug it in and again, it will power everything except 3 of my drives. Once I plug in any of the 3 drives the PC powers up for about 1-3 seconds and powers off. This occurs with any combination of drives. Next I grab a paperclip and rig the 300w PS to be always on, plug 3 of the drives (and a case fan) into it and leave everything else running off the 400w. Everything works fine, I'm actually playing games as I type this. Anyone have any insight? I'm completely stumped.

Specs:
Athlon XP 1800
Globalwin CAK38
MSI K7T266 Pro2-R
2x512mb Micron DDR
GF3
Hercules GTXP
3Com NIC
TVWonder VE
Adaptec SCSI
CDRW
DVD
3 IDE
2 SCSI
2x120mm Fans
2x12" CC tubes (not currently powered)
12" neon (not currently powered)

 

[Magicthyse]

Seems like you're overloading one of the rails...

 

[IBDoomed]

Hmm, that sounds possible. I'll have to check into what these HDs pull. Any guess as to which rail? Obviously either +5 or +12.

According to the data sheet, this Antec outputs 40a on +5 and 12a on +12.

 

[IBDoomed]

I figured it out. Its the +12v rail.

20gb Seagate Cuda IV 2.8a
20gb Seagate Cuda IV 2.8a
60gb Seagate Cuda IV 2.8a
9.1gb WD 1.5a
9.1gb Quantum (unknown but assuming 2.0a or less)
total = 11.9

Now considering I've not alloted for the board or any other device needing +12 there's no doubt I'm way over the given 12a. Now to decide what to do about it.

 

[HelzBelz]

Indeed, with so many drives (high powered ones), you could easily overload one rail (here, the +12V), while not reaching the max output of your PSU (the other rails not being used to their respective max).

Your first solution (2 PSUs) is a good one. You may as well rig the 300W one to power-on with your system.

Or, get an even more powerful Antec (regarding the +12V amps rating...)

Good luck !

 

[IBDoomed]

Using the two PSs causes too much heat in the system and hard locks during the hot part of the day (it's hot in my house) so I can't do that. I'll just return this crappy antec and buy a real PS like an Allied that has 20a on the +12.

 

[HelzBelz]

Well : Allied, Enermax, Delta, Lite-On, Fortron, Sparkle (and even Antec) will do fine; Antec does have quite a good reputation for quality.

So, it's really a question of the current available to the +12V rail for your particular situation. Shop around !

 

[IBDoomed]

I've always had good experience with Antec until now. I guess I just don't see the reasoning behind a 400w PS with such low amps on the +12. That's like making a car with a massive V8 and only a one gallon gas tank, completely worthless.