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POST problem 3

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qmann

IS-IT--Management
May 2, 2003
269
CA
I have a friends computer that i am trying to fix. It goes into a post beeping error when it starts up. Long continuos beeps. I have reset the CMOS and it actually works. I go through everything and it seems to be fine. Then I power it down. After about two hours I check it again and same problem. Could this be the CR2032 battery located on the motherboard?
 
as for the temperature monitor.. it does have one but it has been disabled. But that was after the defaults were loaded so maybe that could have been the problem, i'm just going to unplug for half an hour or so and see if that does the trick.

I'm also trying the screwdriver trick to see if it is the power button.
 
nope.. no go on above mentions...

I have tried to change the following in the bios.. maybe this will do something

I actually turned on the heat alarm to 90 degrees
RAM was set to auto.. i actually selected DDR 266, which is the RAM that is installed.. maybe for some reason it wasn't autodetecting the RAM correctly
 
No go on BIOS settings change.. i am running out of ideas... at this point does it not have to be the motherboard?

 
At this point, here's what you need to do unfortunately.
Take the mobo out of the case and take out all pci cards that are not needed. If you have onboard sound and video then you dont need any pci cards.
Only have monitor,keyboard,ram, and power supply connected, and make sure all power supply connections are connected to the mobo. If its P4 that means to connect the extra 4 pin 12 volt connector. And dont have any case connectors connected to the mobo.

So you have the mobo and power supply out on a table-top with foam underneath it and only the above-mentioned connected, with no unnecessary pci cards installed.

Now re-set the bios and then try and boot.
I dont blame you for not wanting to take it all apart, but at this point it may be the only way to find out if the mobo is bad for sure. And, if so, you will likely be taking the mobo out anyway.
Do you have a digital multimeter to test the power lines on the power supply if you still have problems?




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No I do not have a digital multimeter to test the power lines. I also wanted to make you aware that resetting the cmos sometimes takes multiple tries before it actually works
 
Hey, just noticed, thanks for the star!

Well, i do suggest you take the mobo and power supply out of the case. For one thing, if we can get it going then you can also clean the dust and dirt out. More importantly, shorts often develop between the case, the mobo, and the case to mobo wiring. Taking mobo and ps out of the case eliminates all these as potential problems, along with taking out all pci cards not needed to boot. In addition, it forces a re-install of all the ide and power connectors.

The multimeter, well, all us tech-heads, geeks, or nerds need to have one. Often a power supply will be bad and we dont know as it still boots up the computer but it can still cause problems. In your case it could be the problem and you cant even boot. So, for the sum of around $10 you can get a digital(not analog) multimeter that will test the 3.3,5, and 12 volt lines from your power supply. I can supply you with a diagram tutorial on how to do this and its easy! You can also google it yourself. But get the digital not the analog, the analog has a needle instead of the numbers on the digital. Analog, i have heard, is not good for computers. I could be wrong but i figure why take a chance, its what i have read and i believe its likely true.


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I forgot, try the big-box warehouse-type lumber stores, or perhaps walmart. Sometimes you have to work a bit to get a good deal on one. Where i live its Canadian tire that always has them on sale, lol.


Good advice + great people = tek-tips
 
Garebo,

Great advice thanks! I would really appreciate that diagram. I'll head out and get a multimeter today.. (what section would that be in). Then i'll test the power supply.

One more word on this issue. There was a section on the bios that allowed me to change DRAM status, i changed it to 'safe', it was on normal before... the thing that is bothering me with this is when i initially went in to change it the first time it actually froze on me. I had to reset to get into it again. I have never had the bios screen freeze on me before.

I am also trying to leave the computer on standby.. (just a regular shutdown) that way power is still being supplied to the motherboard, this should tell me whether there is possibly a bad connection between the motherboard and the CMOS battery. Is it possible to test that CMOS battery with the multimeter as well?

If you can send me that diagram it can be sent to qsprik@yahoo.ca. Once again thanks for all the help. Your promptness and ideas have been extremely helpful.. actually learning a little bit more than i originally knew.. thank you so much.

 
You're welcome, people here have helped me out a lot!

The diagram can be googled so i will do that.

You can get the multimeter in the electrical department of the big-box, lol. Or the hardware, tools, electrical section of, say, walmart. I can see it hanging there, lol.

Yes, you can test the battery with the multimeter. Just set it to 3 volts and test it. If there isnt an exact 3 volt you then set it on either ac or dc, i always forget, lol. Look at the manual, but yes you can test the battery for sure.
Oh, ya, i get blasted when i put my email addy in, so maybe you shouldnt, the bad guys can possibly farm for it and find it here. Best to put garebo (at) geek-in-training (dot) com.

The "safe" setting on your ram is just fine for now, its the default, minimum, safe setting.



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By the way, you can use a multimeter on your puter and house wiring, cars, batteries, etc.

great one here, you sign up for free membership, great info place too!! They dont bug you either.
Plus, here is there multimeter tutorial:

looks like a good one:







- they have info but you have to find it

I have one somewhere but i cant find it. it comes from the mueller book and it can be googled, just cant find it at the moment. Wait a minute, i do know, its in the tec republic listing above, they got it from Mueller book!!!

You have more than you need there, lol.


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What is my connector type called??? It is not the p4 p5 connector, it is a, how can i explain it.. 4 prong connector - from power supply to motherboard - two black, two yellow.
 
the 2 yellow, 2 black, white 4 pin connector is the power for the Pentium 4 cpu. This is new, started with Pentium 4 and not needed for AMD cpus.
This connector connects to the other fitting for it, its also white and its on the mobo right near the cpu\heatsink\fan. It only plugs in one way, you cant go wrong. If you didnt have it connected before then that is the whole problem right there!!

The other connector is your standard ATX mobo to power supply connector, its white plastic and has 20 pins total, 2 rows of 10 pins each.



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it was plugged in before with no problem.. when it is unplugged, it won't boot of course but not POST beeps
 
If its P4 it must be plugged in and i believe you are saying it was plugged in all the time, which i believe as it wont boot if not plugged in and it did boot before.

Let me know when you have taken the mobo and power supply out of the case as per my suggestion above.
Or when you get the multimeter.


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I don't know how to work this stupid thing. I've set it up just to test the battery for now. I got a mastercraft 52-0055-6 deluxe. I'm just not sure how to set it up.

There are several different voltages to set-up as well as the red having several options - 10A, A/mA, and v/ohms
Which one do i select? and i'm pretty sure i need to set it up at 20.
 
Ok, then take the mobo and power supply out of the case and set up as described as above.
Then try and boot. If no good then reset the bios and try and boot again. Do you have a manual so you can see how to properly re-set the bios as some are different from standard, some even want you to boot when jumpers are on pins 2 and 3, but most want you to put jumper back on pins 1 and 2 and then boot.

Good advice + great people = tek-tips
 
Ok, before i take out the motherboard i tried a couple of things and found some interesting results.

The purple wire, which is the standby, should have 5 volts going to it.. the most i see is 3.20 volts. While i was doing the testing and it was beeping several times.. after about the 12th beep or so it automatically started loading.

Is it safe to say it is the power supply?? Would 3.2 volts to 5.0 make that big of a difference.. especially since it is the standby power?

Let me know what you think!
 
The multimeter strikes again!

Heres what the book says on the standby power:

The motherboard (under operating system control) can use the FanC signal with variable voltages to control the operation of the power supply's fan, shifting it into a low power state or shutting it off completely when the system is in sleep or standby mode. The ATX standard specifies that a voltage of +1v or less indicates that the fan is to shut down, whereas +10.5v or more instructs the fan to operate at full speed. The system designer can define intermediate voltages to operate variable-speed fans at various levels. If the power supply does not include a variable-speed fan circuit, any voltage level higher than +1v on the FanC signal is interpreted as a command to run the fan at its full (and only) speed.

Some high-quality switching power supplies have built-in load resistors and can run under a no-load situation because the supply loads. Other high-quality power supplies, such as those from PC Power and Cooling, have no internal load resistors. They require only a small load on the +5v line to operate properly. Many of the cheaper clone supplies, which often do not have built-in load resistors, might require +3.3v, +5v, and +12v loads to work.

So far it doesnt look good.
Maybe you want to do some more testing but it could be we have the culprit here. Do you have another power supply you can hook up to this mobo? It does sound like the power supply is failing.






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Be sure you have enough +5v power to run all your expansion cards, especially PCI cards. It pays to be conservative, but remember that most cards draw less than the maximum allowed. Today's newest processors can have very high current requirements for the +5v or +3.3v supplies. When selecting a power supply for your system, be sure to take into account any future processor upgrades."

I get this stuff from a book i have on power supplies.


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