--solved--- Please help: a 5v rail question (motherboard (not an Epox)or PSU at fault?)

[Vinny N]

Yep, I'm still running a cursed MSI K7T Pro2-A.
It went bad on me in early September (was probably the SC1155 from what I've read during, and after the RMA process), RMAd it back, and I'm running the replacement now.
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CPU was and currently is an Athlon Thunderbird 1.1ghz(100mhzFSB/200mhzDDR).
PSU was and currently is an Enermax 451PVE(431w).
Line Conditioner was and currently is an APC Line-R 1250.
(If wanted, other specs can be seen in system rig profile in signature, Vinny's system)
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Nothing is overclocked.

All readings done with MotherBoardMonitor 5.09 for the K7T Pro2A, it seems reflective of the BIOS indicators as well.

I unfortunately don't recall the voltage readings before the original board poofed in September (that would probably tell me if it more likely the board or PSU at fault).

I do recall that when I first fired up the RMA replacement board (early-mid October), that the 5v rail was 4.98, occassionally drifting down to 4.95, rarely 4.93, and staying at 4.98 very consistently. It behaved like that for several days(3-5).

It's declined since then.

Now I never see 4.98, I think 4.95 is VERY rare (though I haven't seen that in two weeks), 4.93 occurs as rarely as before(though I don't think I've seen it for days(6)), 4.91 is where it sits at on a cold power up if I'm lucky (might have seen one in the last 36 hours), 4.86v or 4.88v is very typical for a cold power on now.

It's gone as low as 4.76. It's at 4.83 now (has seen a high of 4.86v since this cold power on period). It's not uncommon to be between 4.81 and 4.88. Sometimes it sits at 4.78 (I usually do a warm reboot to see if it budges at all, but will opt for a cold power off/on, as I don't want to risk it running any lower).

I have blown the system out with a can of compressed air for the sake of neatness and paranoia (That was the previous off period).

My question is whether or not this 5v rail problem is the Enermax PSU slowly dying, or the MSI K7T Pro2-A slowly dying?

I've already had a bad experience with the K7T Pro 2-A and now that I've been reading one too many bad things about the Enermax PSUs these days...
I worry.

I've been considering just buying an Antec PP403X or a Sparkle FSP400-60GN to see if that fixes this, but that's a lot of money. Unfortunately, I don't have another good quality power supply to test my setup with.

I hate to be thinking about this during the last few weeks of the semester, heck I should be sleeping or reading now, but at this point, it's bothering me enough that I could probably stomach buying a new motherboard and PSU so I don't have to think about it. I could justify buying one or the other but I really can't afford to replace both though

So please, does anyone have any ideas?


Many thanks in advance!

-Vinny


note: I know I didn't describe any problems, that's because I'm not really having any.
But I definitely consider this "5v rail declining rating" a problem especially when it just slowly seems to be happening for no reason I can see.
Besides, if it gets any lower than 4.76v, I'm going to have some real problems as I'm sure some Epox+Enermax owners might be able to tell me.

I don't know what the temperature of the voltage regulators and if that affects the SC1155 chip and somehow the 3.3v/5v readings(I've read somewhere that it might) but cooling is:
1 intake 80mm, 1 exhaust 80mm, CPU is using the default retail HSF (PCTC was never used, Artic Silver I is applied).
MBM 5.09 reports now(pretty much idle) CPU temp: 36 C, System temp: 26 C. Vcore: 1.75v(BIOS is set at 1.70, BIOS reports 1.68. When set at default, BIOS would report 1.72, MBM 5.09 would report 1.80, I've tried the default settings, it has made no difference on the 5v rail).

Please forgive trangressions against the english language, I'm dead tired.

 

[Jiggz]

I can't believe your system is still not having problems despite the very low 5V rail. Most mobo would have hang or rebooted at voltages below 4.9V. At any rate, it sounds like the problem is on the PSU. Enermax is well known not able to keep the 5V rail within +-5% or even 10%. My recommendation will be if possible is to get the PSU tested either with another unit or have a multimeter tester connected to it. The bios and MBM are not always accurate with their readings although they are always in the "ball park". Sparkle and Antec are probably one of the best PSU in the market. Even a simple 350w sparkle or antec can easily beat your 450W Enermax when it comes to voltage regulation. I'll say buy either one of these two brands and then sell off your Enermax at the For sale/trade forum. With it hyped name and high rating it'll go by fast!

 

[Vinny N]

Well I used the Enermax PSU on an Intel D815EPEA with a Celeron 500 for a while, but that was probably a month ago.
All the other components were carried over so only the mobo+CPU were different.
Unfortunately I didn't use MBM 5.09 for measurements, I used the Intel Desktop Management program.
I believe it reported 5.00v(idle), and 4.98v(under load).

Do you still think it's the PSU, that it degraded since then?

Perhaps this is pointing out that the Enermax PSU 451PVE didn't make AMD's approved PSU list for CPUs 1.1ghz or higher for a real reason? (contrary to speculation back then that AMD just didn't get around to testing it with faster CPUs).

Heh. Freaking swings of popularity. Swayed my decision to get the MSI K7T Pro2-A, and the Enermax.
If only I went with an A7V or A7V133 and a Sparkle when I had the chance...

Oh well.

Thanks for any more ideas or opinions people can offer.


edit:

Jiggz, Regarding problems so far:

It's been on since my posts yesterday/this morning.

readings:
low of 4.78v, current of 4.81v, high of 4.86v, average of 4.83v

I just had Outlook Express 6 crash out on me (first program to crash so far), but I'm running 98SE at the moment, so it's definitely not too unusual for a crash like that.
I'm going to reload Windows 2000, but I'm sure that'll just make the crashes less likely to come out (which is a good thing I suppose )

 

[Vinny N]

^bump

I hope this is okay, it's been 24 hours since last post...and it's on the third page of the forum, and my view setting is 100 topics per page...

I need some more opinions before I spend money on a new PSU and/or motherboard.

 

[Mem]

My MSI K7T Pro rig uses the 350w Enermax and I get 4.98v on the 5volt rail,anyway before this I was using a Macron 300w and that was around 4.95v so I guess it could be a faulty PSU that`s not working right.The only way to find out is change PSU.

Side note my other rig uses the 431w(465 VE model) Enermax and I get 4.98-4.99v on my Epox 8KHA+ board.

 

[Vinny N]

Allright, I'm going to kick myself really hard now.

I decided to restart, jump into the BIOS, and open up the case.

I move the really long enermax ATX power cord+connector from the place where I tucked it in.

Yep. 5v rail jumps from 4.83 to 4.97(low of 4.93, avg 4.95, consistent 4.95).

Yeah...must have been forcing a kick in the wire or something...geez...

I can't believe that drove me insane...

I wonder how much power it was really getting then? After all, I didn't have any serious problems even when it went as low as 4.76v.

Oh well, saved myself lots 'o money


edit:

trying to straighten it out a bit more now, 4.98v (avg and consistent!) Slightly impeded airflow is a small price to pay hehe.

 

[Rahminator]

My 300W Antec never dips below 4.89, and in fact, it's running at 4.89 90% of the time. If not, it's either 4.92 or 4.95. How low does the V5 line have to go before one is starting to have stability issues, like random reboots. I've heard it's around 4.7, is that true? Thanks.

 

[RossGr]

Just a note, The ATX specs for the 5V supply is +/- 10% so as long as your 5V reads between 4.5V and 5.5V it is in spec. You motherboard should be able to run anywhere in that range. If it will not then the trouble is with the mobo and not the PS. The ATX spec is available as a PDF file here ATX Formfactor

 

[soulm4tter]

phew, had me worried............mine always sits at 4.88. but it never crashes so i shouldn't worry.