PC doesn't get passed POST, fans working, no

September 13, 2009 at 21:43:59
Specs: Windows Vista
Hello, I'm having a bit of a problem here, hope you can help me find what part of the computer is behind this.

For the past month, I've seen my computer restart on its own spontaneously about once or twice a week. Then yesterday I got home to a computer with a frozen window, mouse and keyboard not responding at all so I restarted but the computer would not start, the fans were working but no beeps and no monitor response.

Tried reseating the RAM and unplugging everything but the motherboard but still nothing, so I'm thinking it's either the motherboard or the PSU, but I really can't be sure and I can't really afford to buy both of those things in order to find out who the culprit is. So any help would be much appreciated.

Here are my computer specs or at least, those I couldn't find out :

ACER Aspire M5640-E5511A

- couldn't find the motherboard model/brand name
CPU : intel Core 2 Quad Q6600
RAM : 4GB DDRII
Video : integrated graphics
PSU : no idea.

Thank you,
Francis.


See More: PC doesnt get passed POST, fans working, no

Report •


#1
September 13, 2009 at 22:26:46
Usually there's nothing wrong with the mboard, unless it's got this problem:

Open up your case and examine the mboard to see if you have bad capacitors, and/or other findable signs of mboard damage .

This was the original bad capacitor problem - has some example pictures.
History of why the exploding capacitors and which mboard makers were affected:
http://members.datafast.net.au/~dft...

What to look for, mboard symptoms, example pictures:
http://www.badcaps.net/pages.php?vid=5
Home page that site
- what the problem is caused by
- he says there are STILL bad capacitors on more recent mboards.
http://www.badcaps.net/

Pictures of blown capacitors, other components - power supplies, Athlon cpu's, etc.:
http://www.halfdone.com/Personal/Jo...
........

Unplug the case/power supply.
Power off your monitor.
Open up the case by removing the left panel as seen when you're looking at the front of the case.
Check all the connections of the wiring to make sure they are all the way onto their pins and into their sockets, especially the main connector from the power supply. The wires close to the mboard going into the main power connector/socket should be more or less perpendicular to the mboard surface rather than at an angle. Most mboards require an additional connector from the PS be connected to a socket for power on the mboard, other than the main socket. Make sure all cards in slots are all the way down in their slots.

See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:
http://www.computing.net/hardware/w...

While you're in there, if the cpu fan/heatsink has mung (dust, lint, etc.) on it, clean it off, but DO NOT use a vaccuum cleaner to do that (they produce a tremendous amount of static electricity when running, and anything connected to them can discharge that to your components) - use canned air, or an air nozzle if you have access to an air compressor, or an artist's brush that can be used in small spaces, etc. It may be difficult to clean the top of the heatsink under the cpu fan - the most likely place to have mung on it - and the bottom side of the cpu fan blades unless you remove the fan. If you have a case fan, clean that too if it needs it.

With the cover still off, restore the AC power, start the computer and make sure the cpu fan spins
- if it doesn't spin, if you're sure the power supply is working okay, don't use the computer until you have found out why it doesn't spin (see next below).
- if it doesn't spin, if you're sure the power supply is working okay, don't use the computer until you have replaced it.
If it spins too slowly, and/or if it makes rattling or screeching noises, most likely to be noticed when the computer has cooled to room temp, has not been used for a while, and then is started up, the cpu fan's bearings are failing - replace it as soon as you can.
.......

There's usually nothing wrong with the processor - cpu - unless the cpu fan failed.

If the cpu fan does not spin,
- if it's blade moves easily when you try to spin it with your finger, there may be nothing wrong with it. Try removing it and connecting it to another desktop mboard's 3 pin header for a case or power supply fan - if it spins, your processor is probably okay - if it doesn't spin your processor MAY be burnt out.
- if the cpu fan is difficult or impossible to spin when you try to spin it with your finger, your processor is probably burnt out.
.........

Failing power supplies are common and can cause your symptoms.
Check your PS.
They often partially work, fans and hard drives may spin, leds may come on, yet you may get no video and the mboard will not boot all the way.
See response 4 in this:
http://www.computing.net/hardware/w...

If it is failing, you can usually replace it with any decent standard sized standard ATX PS with the same capacity or greater.

Standard (PS/2) power supply size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.

Don't buy an el-cheapo PS.
See response 3 in this:
http://www.computing.net/answers/ha...

Your power supply must have at least the minimum capacity required to support a system with the graphics card you are using installed, or the max graphics card you might install in the future.
(Onboard video - video built into the mboard - IS NOT A CARD!)
You can go to the video card maker's web site and look up the specs for the model - often under system requirements - the minimum PS wattage, and, more important, the minimum amperage the PS must supply at 12v is stated. If you don't find that, any card with the same video chipset including any letters after the model number has very similar minimum PS requirements.
Some power supplies have more than one +12v amperage rating - in that case you add the rated max amperages to determine the total +12v amperage rating.
.......


Report •

#2
September 14, 2009 at 05:02:05
Start by turning off the "automatically restart" feature.

Report •

#3
September 14, 2009 at 08:49:35
"Start by turning off the "automatically restart" feature."

In Vista, probably Windows 7 too
Control Panel - System - Advanced System Settings - Startup and Recovery - System Failure section - click on the small square box before Automatically Restart to remove the checkmark if it's there.
Click on OK at the bottom of the same window.

If you then get a blue screen error message, look at and note all of it's details.
......

A failing power supply is the most likely cause of your problem, if don't get blue screen errors messages and nothing else seems to be wrong with your hardware or connections.


Report •

Related Solutions

#4
September 17, 2009 at 17:12:19
Thanks you all.

Turns out it was the motherboard that fried, I changed it for an ASUS P5KPL-AM SE, and except for the front panel connections, everything went smoothly.

But since this new motherboard's been up and running the fans have been working crazy making them far from silent, does that mean any problem of some sort ?

Thanks,
Francis.


Report •

#5
September 17, 2009 at 19:05:52
"Turns out it was the motherboard that fried,..."

What symptoms? Bad capacitors??

"...except for the front panel connections, everything went smoothly."

The markings on the mboard can be confusing - it's easy to do that if you READ THE MANUAL! If you don't have it, download it!

"But since this new motherboard's been up and running the fans have been working crazy making them far from silent, does that mean any problem of some sort ?"

Did you install the drivers for the mboard?
If you didn't, DO THAT!

The same applies when you change mboards and use an existing Windows installation:

Whenever you load Windows from a regular Windows CD (or DVD) from scratch, after Setup is finished you must load the drivers for the mboard, particularly the main chipset drivers, in order for Windows to have the proper drivers for and information about your mboard hardware, including it's AGP or PCI-E, ACPI, USB 2.0 if it has it, and hard drive controller support. If you have a generic system and have the CD that came with the mboard, all the necessary drivers are on it. If you load drivers from the web, brand name system builders and mboard makers often DO NOT have the main chipset drivers listed in the downloads for your model - in that case you must go to the maker of the main chipset's web site, get the drivers, and load them.

What cpu are you using?
Your cpu must be on this list. This mboard may not be able to handle cpus that use more than 130 watts:
http://www.cpu-upgrade.com/mb-ASUS/...

The blue highlighted links on the left beside each cpu listing show you which specific cpus work, and near the bottom of the info there it specifies how many watts it consumes.

Did the cpu fan/heatsink come with the cpu, or did you buy that separately, or use a combo for/from a previous cpu?

This mboard isn't a brand new model. If this is a used mboard, did you check in the bios Setup to see if the system is being overclocked? If you're not sure, load Optimized defaults. Also check the manual - sometimes there's a jumper on the mboard that adds .x volts to the cpu core voltage, and on another Asus model I installed, the increase in cpu voltage did NOT show up in the current voltage readings in the bios Setup - the brand new mboard was set that way!



Report •

#6
September 18, 2009 at 01:58:52
Thanks for the help !!

"The markings on the mboard can be confusing - it's easy to do that if you READ THE MANUAL! If you don't have it, download it!"

No biggie, the plastic connector wasn't compatible with the new motherboard, also, it's cables were too short so I had to solder my own. I searched everywhere for an ACER inspire manual, doesn't seem to exist, very strange thing.

"What symptoms? Bad capacitors??"

I don't know why the motherboard fried, it didn't look damaged at all, I wouldn't know where to start to figure this out.

"Did you install the drivers for the mboard?
If you didn't, DO THAT!"

Drivers for the new motherboard are fully installed.

"What cpu are you using?
Your cpu must be on this list. This mboard may not be able to handle cpus that use more than 130 watts:"

Q6600, seems to be handled by the motherboard.

"Did the cpu fan/heatsink come with the cpu, or did you buy that separately, or use a combo for/from a previous cpu? "

Well the whole computer was a pre-assembled, ACER Inspire M5640, I only changed the motherboard so the CPU and heatsink/fan are the same as with the old motherboard.

"This mboard isn't a brand new model. If this is a used mboard, did you check in the bios Setup to see if the system is being overclocked? If you're not sure, load Optimized defaults. Also check the manual - sometimes there's a jumper on the mboard that adds .x volts to the cpu core voltage, and on another Asus model I installed, the increase in cpu voltage did NOT show up in the current voltage readings in the bios Setup - the brand new mboard was set that way!"

I bought it new, but I will still check this, you can never be too sure with some small computer stores.

Thanks for all the help, I'll update here when I check this.


Report •

#7
September 18, 2009 at 07:32:38
"No biggie, the plastic connector wasn't compatible with the new motherboard, also, it's cables were too short so I had to solder my own. I searched everywhere for an ACER inspire manual, doesn't seem to exist, very strange thing."

That's typical for a brand name system - usually a one piece connector for the front panel, zero info on the brand name builder's web site about which pin on the mboard on the header is for what, what wire is for what on the one piece connector. It's compatible with the specific mboards used with the particular case by the builder, but not necessarily compatible with other mboards. It's as if the builder assumes those are things the buyer of a brand name system doesn't need to know.
Good for you for doing what you needed to do to fix that.
In many cases, at least for desktop systems, if one digs around one can find who actually made the mboard, and often find the manual and the pinouts for the front panel header, which tells you what the wiring of the one piece connector from the case must be.

Okay then, according to your supplied info, I don't know what would cause the fan(s) to behave differently than they did before with the same components as before. Case fans usually have no temp controlled speed control in the bios, but some have a temp control in the case wiring for them. A power supply fan's rpm, if it has a temp control, is determined within the PS, not by the mboard - you could check to see if there's a buildup of lint etc. inside of it - if there is it's obvious at the back of the case where it's cooling air is exhausted, perhaps where air is sucked into it on the inside of it too. The cpu fan might have a feature that can be turned on in the bios, if the particular cpu supports it, that reduces the rpm according to temp when the fan doesn't need to run as fast.


Report •


Ask Question