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Bad ATX PS? Bad RAM? Bad MOBO?

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November 25, 2010 8:55:03 PM

I just returned from 4 weeks away & powered up my desktop. No beep/POST, screen dark, only fans. Cutting things very short here, with only the MOBO/HD/DVD connected to PS (no RAM) I get beeps. But with any of four RAM sticks installed, no beeps. (Symptoms seemed flaky before, but now have settled into the above description.)

Measurements:

1) with 24-pin MOBO connector taken out, green/blk jumper installed, DVD & HD connected as loads:
Orange: 3.34
Red: 5.02
Yellow: 11.81

2) 24-pin connector installed to MOBO, other loads as described above still in place:
Orange: 3.33
Red: 5.05
Yellow: 11.65
(two long beeps)

3) Now with first stick of RAM installed, otherwise as above:
Orange: 3.33
Red: 5.05
Yellow: 11.66
(but NO beeps)

I've tried individual sticks of RAM in each slot, never getting a beep as long as any stick is installed anywhere.

Given my limited knowledge, I would think my measurements/tests suggest bad RAM. But...four sticks of RAM going bad simultaneously doesn't seem right, either. Are there other tests indicated here to complete a proper diagnosis?

Hardware: ASUS IPIBL-LB, all stock stuff in an HP m8307c other than a replacement vid card and warranty-replaced HD that's over a year old.
a b ) Power supply
November 26, 2010 12:37:16 AM

11.66 volts is low. may be a bad psu. Do you have a video card? or is it on board video? Do you normally keep the PC on all the time? Its common for capacitors to die if that is the case and the have then been left off for a prolonged period. Any bulging/leaking capacitors on the motherboard?
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November 26, 2010 3:02:23 AM

iam2thecrowe said:
11.66 volts is low. may be a bad psu. Do you have a video card? or is it on board video? Do you normally keep the PC on all the time? Its common for capacitors to die if that is the case and the have then been left off for a prolonged period. Any bulging/leaking capacitors on the motherboard?


Thanks, iam2thecrowe - to answer your questions:

11.66V is low, but... significantly? Is 12.0V the ideal? If so, that's only 3% low, so I would think it would be within tolerance. I'd like that solution if the voltage really dipped a lot when PS connected to loads, but it's only dropping from 11.81 (no load) to 11.65 (adding HD, DVD, & with/without RAM) so gut feeling is that's not unreasonable. Not so?

Yes, I have a PCIe video card - though not installed now or during listed testing.

Yes, normally I don't shut down. No bad-looking caps on the motherboard.

I'm wondering if substitution of a probably-good PS would be worth doing if I can get my hands on one (none scroungeable that I know of right off, but I've not really looked.)
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a c 144 ) Power supply
November 26, 2010 3:53:13 AM

Work through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-postin...
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.

I have tested the following beeps patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different.

Breadboard - that will help isolate any kind of case problem you might have.
http://www.tomshardware.com/forum/262730-31-breadboardi...

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. You do have a case speaker installed, right? If not, you really, really need one. If your case or motherboard didn't come with a system speaker, you can buy one here:
http://www.cwc-group.com/casp.html

You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU.

Motherboard LED's mean very little. When on, all they are telling you is that the computer os plugged into a live power socket and the PSU is switched.

Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

If no beeps:
At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.
http://www.youtube.com/watch?v=5FWXgQSokF4&feature=yout...

This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card. Silence or long single beeps indicate a problem with the memory.

Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.

Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step.

It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
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November 26, 2010 7:56:42 AM

jsc said:
Work through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-postin...
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.

I have tested the following beeps patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different.

Breadboard - that will help isolate any kind of case problem you might have.
http://www.tomshardware.com/forum/262730-31-breadboardi...

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. You do have a case speaker installed, right? If not, you really, really need one. If your case or motherboard didn't come with a system speaker, you can buy one here:
http://www.cwc-group.com/casp.html

You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU.

Motherboard LED's mean very little. When on, all they are telling you is that the computer os plugged into a live power socket and the PSU is switched.

Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

If no beeps:
At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.
http://www.youtube.com/watch?v=5FWXgQSokF4&feature=yout...

This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card. Silence or long single beeps indicate a problem with the memory.

Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.

Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step.

It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.


^+1
I follow this procedure often and it works.
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November 26, 2010 8:34:06 AM

Quote:
Work through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-postin...
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.

<edits here & below>

At this point, you can sort of check the PSU...<I don't currently have access to a spare PS>... use a DMM to measure the voltages....If it looks like the PSU is good <yes>, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card. Silence or long single beeps indicate a problem with the memory.


Yes, I was indeed working through that list, at least to the extent that it applies to my not-just-built system, though I am not breadboarding - mobo/PS are still in the case.

That last sequence brought me to where I am stuck: as soon as I install any of the RAM, the beeps cease. Prior to any RAM installation, I get two long beeps, the second longer than the first. As far as I can see from the troubleshooting checklist, there would be no point in continuing without being able to install at least one stick of RAM.

So - are there circumstances wherein four memory sticks get smoked simultaneously? Or is it more likely that this is a borderline PS problem, say? Or... something completely different?

Thanks for your attention, jsc.

[bump/edit]

To be thorough, I pulled mobo/PS from case and now just breadboarding. Same symptoms: any RAM installation => no beeps. PS voltages are still within tolerances, measured with or without RAM. Can PS be bad regardless of these measurements? Or is all my RAM suddenly toast? Or some other cause?
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November 26, 2010 8:38:01 PM

<another bump attempt.>
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November 26, 2010 11:46:06 PM

New data: I connected a new-out-of-box PS - and got the EXACT same symptoms.

Do I now have to conclude that the RAM (all four sticks) went bad during my absence? That would seem...spiteful and unlikely, no? But installing any of the four sticks results in "no beep" condition.

I really don't want to buy replacement RAM, only to find that this is actually a mobo problem. Is that possible, or perhaps even more likely?

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November 27, 2010 1:23:16 AM

is that one of the hp's that was affected by the bad caps problem? Those are pretty much the symptoms you get.
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November 27, 2010 2:34:49 AM

Thanks, rand_79. Wikipedia gives an interesting read on this (http://en.wikipedia.org/wiki/Capacitor_plague) - I guess I was on a non-electronic planet when people were having these capacitor issues (myself included, perhaps - replacement of one bulging PS cap in my c.2003 LCD monitor fixed it).

But there are two things that make me think this isn't likely really my problem, aside from the lack of visible evidence of any bad caps on my mobo:
1) "HP reportedly purged its product line in 2004" (can't find anything on HP's website to corroborate this, but it may be worth a call or twelve to verify)
2) I got my HP as a refurb in April of 2008, so it "should have been" well clear of such problems by then.
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a b ) Power supply
November 27, 2010 7:35:19 AM

well, since your system is stripped down to just motherboard ram and psu.. you have tried another PSU to no avail, and its not likely all ram sticks are bad, the last 2 things left are CPU and motherboard. CPU's rarely fail (i have seen about 3 faulty CPU's ever which were all new celerons with dead shorts), so my conclusion would be a fault with the motherboard.
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November 27, 2010 10:08:31 PM

Sounds like a similar issue with my asus P7P55D-E Pro motherboard. All other components were fine and exact same symptoms. Sent the board back for RMA. Also checked asus forum to find multiple cases all the same, though there were some on new boards.
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November 27, 2010 11:22:22 PM

At this point, since I'm well past RMA days, my choices are:
a) get an $88 refurb mobo (delivered) from Chinese ebay firm, and hope that my CPU is really OK, or
b) spend, well, somewhat more on a new mobo & CPU bundle, but have less worry - maybe. (That also opens up a whole new set of decisions I'm ill-equipped to make.)
One key deciding factor: I assume there's no way around having to reload Windows regardless, right? That alone costs me about a day in aggregate, if history repeats.
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Best solution

a b ) Power supply
November 28, 2010 12:50:38 AM

well you should be able to replace the motherboard with any socket 775 board which you can get cheaper than $88. But yes if you dont replace the motherboard with the same model you will likely need to re-install windows. If your using the HP recovery disks/partition it may not work with different hardware, you will need an original windows cd and load drivers manually. I would take my chances that the CPU is ok, it would be 99.9% safe to assume its ok.
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a b ) Power supply
November 28, 2010 10:15:50 AM

808dude said:
<another bump attempt.>

Quote:
Don't...

* Bump posts, claim "first!"


Source.
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November 28, 2010 5:04:16 PM

Thank, iam2thecrowe - I wasn't thinking along those lines at all, but happy to hear it's not likely my CPU is toast, AND that alternative mobos can be cost-effective, since a refurb from China sounds like something potentially capable of creating hair loss. Tiger has over 100 mobos, but when I narrow by criteria that include '775, DDR2 (to re-use my old RAM), and uATX,' I end up with but one option - again, $85, but perhaps better for my purposes since it's got two onboard video outs. If there's an awesome 'other supplier' I'd like to know.

BTW I gave up on HP's discs anyway when I went to Windows 7...weeks before this happened...sigh.
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a b ) Power supply
November 28, 2010 5:32:32 PM

are you sure there are no bad caps on the motherboard. since i know quite a bit about capacitor stuff, just a few question:
are the capacitors on your current motherboard either chemi-con KZQ? (brown color, Y vent top, says KZG on the side)...or nichicon HM or HN, (black, X vent top, says nichicon Hm or Hn on it), both are known to have problems even though they are from a good capacitor brand...check out badcaps.net and click on "technical forums" on the left honestly this sounds like something they could help you with.

on a personal note, im kinda pissed at them for permanently banning me from theyre forums a few days ago :( 
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November 28, 2010 6:42:30 PM

shovenose said:
are you sure there are no bad caps on the motherboard. since i know quite a bit about capacitor stuff, just a few question:
are the capacitors on your current motherboard either chemi-con KZQ? (brown color, Y vent top, says KZG on the side)...or nichicon HM or HN, (black, X vent top, says nichicon Hm or Hn on it), both are known to have problems even though they are from a good capacitor brand...check out badcaps.net and click on "technical forums" on the left honestly this sounds like something they could help you with.

on a personal note, im kinda pissed at them for permanently banning me from theyre forums a few days ago :( 


shovenose - thanks - no, I am not sure of anything...at all...

But yes, electrolytics are all brown "KZG", plus a type that's new to me that look like old-school transistors - in drawn aluminum cases - 'least I think they're caps... None of either type looks bulgy, though, and of course I don't see any leakage. Without having exotic test equipment, is there a reasonable way to test in-circuit? One or two times I was able to spot a bad cap by just testing resistance in situ, but that was on a board with obvious 'stereo' layout that allowed for comparative measurements. Here, I am not even sure which of the 25+ caps to suspect first. I'd surmised that since the no-POST problem crops up as soon as any RAM stick is installed, that there's a common power-feed to all RAM sockets that's got a defective component of some kind in it. If that's a reasonable suspicion, then...maybe one of the caps physically close to the sockets would be a likely suspect. But I loathe the idea of shotgun-replacing caps for a few hours only to have the problem remain. If you can steer me right on this, I'll use my vast political influence to get you reinstated at badcaps.net (yeah, right...) Going there next.

--'pants
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a b ) Power supply
November 28, 2010 8:54:19 PM

um those are probably mosfets if theyre black and square...

yeah chemicon kzg are very failure prone, and they like to fail without showing any signs of failure...i would suggest replacing them. whats the uF value and voltage?
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November 28, 2010 9:09:27 PM

yikes...all 25+? Around the RAM sockets, I see values like 1800uF, 330uf, 6.3V - most I can't read due to tiny size and my eyes crapping out.

I really don't think I would go this route without being able to test them first - hours of parts ordering, board-toasting...only to possibly be rewarded with failure. I could screw up a lot of adjacent stuff in the process of wholesale replacement of caps, in my opinion.

The other devices aren't mosfets - they're two-terminal, round all-aluminum cans that look like old bulky transistors, except with the tops printed with 7X1 / 561 / 6.3V , which I could only guess to be capacitance values.
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a b ) Power supply
November 28, 2010 9:11:42 PM

you mean polymer capacitors? those dont need to be replaced they last forever. i would start with replacing the capacitors around the ram slots. or you send your board in to chris (ownder of badcaps.net) and he'll do a good job recapping the entire thing. and if you do tell him shovenose sent you. :) 
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December 10, 2010 12:39:00 AM

Well, it's been a bad couple of weeks for electronics in my immediate vicinity...amazing, really, and held this repair up by a week or so, but... that'd be another post-rant.

The new mobo with my transplanted original CPU went in about as smoothly as I could have hoped for as a first-timer. The only brief issue was that something must have made the RAM get all verklempt between my sucessful breadboard-pretest and the real, in-case installation. Re-seating RAM did the trick, and... I'm Sure That Will Never Happen Again. Intel's new mobo has a shocking lack of documentation - as a newbie, I'd expected to check a few things during the process, but there was only a huge foldout pictorial with a lot of almost-useless number-keyed views, and virtually devoid of any corresponding written information (yeah, the 'don't work on this while in the shower' warnings were present in a dozen languages, though...) That new snap-in panel for the back connection...<shudder> reminds me of something I sliced my fingers open on when I was a kid.

One item I am sure someone here would know the answer to: there's one odd (HP) connector that's supposed to go to the external-memory console (SD card, Smartmedia, etc) on the face of the PC. It's like half of the standard 9-pin USB-style mobo connector. I was tempted to connect this (four pins, plus one 'blank') to the one-blanked-off 4-pin side a USB jack on the mobo, but...not sure. Is that right?

But most importantly now: I'd of course expected to reload Win7. The original HP mobo (ASUS) came with Vista, which I immediately reformatted out of my life in favor of XP. After 'deciding' to upgrade from a nongenuine XP version, I got HP's Vista recovery discs, in order to have to pay only for the upgrade from Vista to 7 - an installation which, as it turned out, lasted me about a month before the board went up in smoke. Then, in getting the replacement mobo, I'd assumed, perhaps foolishly, that I would just repeat the process of offering it the Vista System Recovery discs, then the Win 7 upgrade discs - but of course my Vista discs were looking for an HP (Asus) mobo, and my replacement mobo is an Intel, so... I get nowhere with the Vista recovery discs. (the product key wouldn't work when I first tried to install directly from the Win7 upgrade discs). Is there a no-cost way to recover the Win7 functionality I had a couple of months ago before the old mobo died?
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a b ) Power supply
December 10, 2010 1:14:00 AM

dont post about "non-genuine" windows-thats against forum rules to even mention it (not that i care i do it too)...
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December 17, 2010 3:38:31 AM

Best answer selected by 808dude.
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a b ) Power supply
December 17, 2010 3:59:17 PM

This topic has been closed by Mousemonkey
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