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Replaced PSU after a power failure killed it. Now system doesnt come up.

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December 7, 2010 11:45:58 PM

Hello,

1. Yes I have read and done all of the "Perform these steps" boot camp :-)

2. System Config A8S-X MB AMD4600 CPU with Air Cooler, 3GB PC3200 OCZ 2-3-2-5 Memory, Currently Apevia 680W PSU, couple of 500 GB SATA HDD's a couple of 160 GB IDE disks, Nvidia GeForce GT240 1GB display, Sony DVD writer - that's it. The entire system is in an acrylic sarcophagus so accidental short circuits can be mostly ruled out.

3. Problem. System was fine and fully functional. Major power failure due to storm. Next day when I turned the system on - I got nasty smelling smoke and a dead system.
To the best of my knowledge the smoke came from the PSU ( a Logisys ) so I replaced the PSU.

4. Observation. On hitting the power on switch the fans of the chassis, the PSU, and the CPU spin for a second and a half and then everything stops.
The LED on the motherboard is glowing.
This is not a repeatable event - I cant press the power on switch and make then spin again. I have to shut down power - till the MB LED goes off.

5. Frustrated freak out efforts.
I isolated the PSU and shorted the MB actuator ( green cable ) with ground - gave it a fan load to start it up and checked the rails power - especially the ATX 12 V 4 connector. ( it was 11.85 v ) So PSU was OK.

I have stripped the motherboard down to nothing but the chip and fan - and memory ( had even taken the memory away ) - No use - the MB led glows but no response otherwise.

Ah yes - I of course did discharge the CMOS early on in the game - but of course as you can see makes no difference.

6. Question.

This peculiar combination of symptoms - The motherboard LED glowing, the momentary burst of life where the CPY fan, chassis fans and PSU fans all spin for about a second and then all die, and cannot be revived in that power session - is completely baffling me. Will some wise soul take pity on me and advise me on the next course of action please ?
a b B Homebuilt system
December 8, 2010 1:04:33 AM

I think I would verify that all the PSU leads are firmly seated, including the CPU 4/8-pin lead. Since an over-heated CPU will shut the motherboard down to protect the CPU, I would then verify that the CPU HSF is firmly seated on the CPU - I might even re-seat it with new thermal interface material like Arctic Silver 5 after cleaning the old material with rubbing alcohol applied to a clean coffee filter.
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a b B Homebuilt system
December 8, 2010 1:17:17 AM

Oh god, this sounds all too familiar, but it looks like you've done my suggestion. Did you pull CMOS, pull power, and hit the power switch a few times?

I literally had the exact, to a tee, symptoms you had recently with a brand new PSU. The CMOS/Cap dump and a few more CTFO lines, and it booted fine, and hasn't had a single issue since.
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December 8, 2010 5:21:53 PM

treefrog07 said:
I think I would verify that all the PSU leads are firmly seated, including the CPU 4/8-pin lead. Since an over-heated CPU will shut the motherboard down to protect the CPU, I would then verify that the CPU HSF is firmly seated on the CPU - I might even re-seat it with new thermal interface material like Arctic Silver 5 after cleaning the old material with rubbing alcohol applied to a clean coffee filter.


Hello treefrog07, thanks for the suggestions. yes i have ensured the seating of the leads. I have been waffling about the TSF though so I will take your suggestion and clean out the old thermal contact crud and give it a new coat of artic silver - re-seat the fan and see how that goes. Honestly I am a little skeptical about the efficacy of this - but right now I am so distracted and baffled ... Hey I appreciate the good thoughts - I dont want my chip to get fried now :ouch: 
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December 8, 2010 5:32:28 PM

jack_attack said:
Oh god, this sounds all too familiar, but it looks like you've done my suggestion. Did you pull CMOS, pull power, and hit the power switch a few times?

I literally had the exact, to a tee, symptoms you had recently with a brand new PSU. The CMOS/Cap dump and a few more CTFO lines, and it booted fine, and hasn't had a single issue since.


jack_attack my good man ! you bring hope ! :bounce: 

Ok - first off - I just removed the power cable - waited for drain ( 2-3 min ) and then hit the power switch quite a few times to "discharge" the psu "charge memory". Unfortunately I did not see anything ( in terms of the fans jerking - led's briefly coming on - or any such activity ). I assumed it would be due to very low power so anyways - after some attempts plugged in power and tried starting up - same problem - brief moment of full activity and everything stops. Second attempt at pushing power on switch elicits no activity - until the power switch on psu is turned off for at least 30 seconds.

Next I removed power cable and discharged cmos ( for a full 20 seconds ) and reconnected power cable - to psu - same problem. :pt1cable: 

All this time I have made sure that the reset cable from the front panel is disconnected to the motherboard jumper "just in case"

Question : Do you want me to Hit power on/off button when the CMOS is being discharged and power cable is off ? Share the beans of wisdom
o mighty jack !
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a b B Homebuilt system
December 8, 2010 10:16:08 PM

When you remove the CMOS battery and power from the PSU, a touch of current is stored in capacitors on the mainboard. When you attempt to turn the machine on, it tries, and dumps what it has in reserve. CMOS does what it can to not reset :) 

Try unplugging the PSU and sliding the 120/220 switch on the back of the PSU a few times. Make sure it's set back to 120 if you're in the states before you power it back up. That's worked on a few dying PSU's before. Don't ask me how I know this.
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December 11, 2010 1:43:31 AM

Hello jack_attack - complete failure of efforts ! :heink: 

1. After my initial efforts failed I even suspected the Cr2032 may be suspect and it registered 2.62 V - eeh - I didnt like it and replaced it with a brand new one which registered 2.86 v out of the packing ( go figure ! )

in any case .. I did disconnect the power cord so the system was isolated from the mains

and did the 120 / 240 switch flip quite a few times

when this did not work on its own,

I expanded this process to doing a cmos drain first ( jumper ) and then having restored jumper did the psu switch flip - and then plugged the power cord and attempted a boot up - no luck a brief moment of actiivity and all stops.

MB led glows strong and steady

Next I went all out. I removed power cord - did the psu switch flip a few times 12 - 15.
Then I did a cmos drain.

Then I removed the cmos battery and did the power switch on off for a few times 10 - 15.

Then,

I replaced the battery, ensured the cmos jumper is in the correct position, connected power to psu, ensured power is in 110 v position and turned the psu switch to on, waited a few seconds before hitting the start switch.

same junk - brief spurt of activity and everything flips to dead. It seems like some heavy duty capacitance charge is building up that is triggering a shutdown.

I am fresh out of ideas.

Oh btw I pulled out the fan and cleaned out the gook and gave a nice thin layer of thermal paste and reseated the fan - did I already mention this ?

Any suggestions ? I am thinking of taking a sledgehammer to the motherboard may fix this problem quite nicely because failing which I may take the sledgehammer to my head - which I dont think is a very good upgrade idea.

Your time and suggestions are much appreciated.

:sarcastic: 
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a b B Homebuilt system
December 11, 2010 3:38:57 AM

I hate to say it to you sir, but it might be your mainboard. You've tried all my standys to get a finnicky system to boot, and that's a common symptom of a bad board. Look carefully at every part of the board, and look for burns, popped/leaking capacitors, anything that shouldn't be there. If it's a burn, it will usually be tiny. We're talking very minute amounts of electricity, they don't arc much. You wouldn't happen to have another board you could swap in there, would you?
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a b B Homebuilt system
December 11, 2010 3:44:28 PM

One other thing you might try, pull the cmos battery and power the system on. Try a single stick of ram. Maybe even try booting with no ram. If you pull ram and or video card, does the board make any noises? Because if you try booting without those the board should beep if it is even half alive.
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a b B Homebuilt system
December 11, 2010 4:15:32 PM

ohiou_grad_06 said:
One other thing you might try, pull the cmos battery and power the system on. Try a single stick of ram. Maybe even try booting with no ram. If you pull ram and or video card, does the board make any noises? Because if you try booting without those the board should beep if it is even half alive.



He's tried all that. I'm pretty sure the board is dead.
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a b B Homebuilt system
December 11, 2010 5:28:46 PM

If hes done those things then I would agree. Best bet then would be grab a new mainboard and chip combo and move on.
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December 11, 2010 5:46:59 PM

jack_attack said:
I hate to say it to you sir, but it might be your mainboard. You've tried all my standys to get a finnicky system to boot, and that's a common symptom of a bad board. Look carefully at every part of the board, and look for burns, popped/leaking capacitors, anything that shouldn't be there. If it's a burn, it will usually be tiny. We're talking very minute amounts of electricity, they don't arc much. You wouldn't happen to have another board you could swap in there, would you?


I tend to agree - You are right. I think it may be a fried board. Matter of fact I do have a spare board lying around ( what are the odds eh ? ) :hello: 

So, I will do the replacement - fire it up and will let you know how that goes - so that we have some conclusion.
I will also look through the current MB for burns, cracks and popped components and let you know. Should take me a day or two. Thank you also to ohiou_grad_06 for advising me here. :wahoo:  I deeply appreciate the same As you can see treefrog07 and jack_attack have ensured I have done the boot camp diagnostics.

Its time as we all agree to do a new MB and put the old one to rest after an autopsy. I must say that was some power failure - I just did not reckon it fried the MB. Well Gee Thanks PG&E.
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a b B Homebuilt system
December 11, 2010 5:47:52 PM

Make sure you Office Space it if you confirm it's done for.
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