Hi,

My computer recently stopped working. There is no power to the CD drive, Floppy Drive or the keyboard. When I press the power button I don't hear the usual beep. Monitor LED stays amber. Nothing comes on the monitor. The computer technician told that the motherboard is gone bad. Before I replace it, I would like to check it my self. Could any one tell me how to determine if the motherboard is the problem. Any help would be appreciated. Thank you.
smahar

Hi,

Sounds more like a PSU (power supply unit) failure to me, as there is no evidence of power getting to any of the componets. Depending on the make/model of the computer, I would at least expect some power still going to say the CD rom drive, even if the motherboard is dead.

Again, depending on the make/model of the computer, look at the back of the computer to see if the fan is spinning in the power supply unit, located where you plug the power lead in.

More details of the make/mmodel of the computer would be helpful.

Hope this helps.

Slim

If all fans and lights do not work(except for the monitor amber light), and the monitor's power cord is connected to a surge arrestor, then there's a problem with either the computer's power cord, the power supply, or the MB.
Check the power cord's output connection for the correct voltage. If the voltage is incorrect or there's no voltage, then replace it.
If it's ok, then check the power supply's leads where it connects to the MB with a voltmeter making sure that it's connected to the MB with the system turned on. You should get the following readings:
Yellow wire and black wire- +12 volts
Red and black- +5 volts
Orange and black- +3.3 volts
If any reading is way off, then replace the PS.
If the readings are ok, then the MB is probably bad.

If the monitor is not connected to the surge arrestor, then check the arrestor's output voltage.
If it's the incorrect voltage or there's no voltage, then replace the arrestor.

If the fans and lights work, then the problem can be due to a bad MB, CPU, memory, or video card.
However, this does not appear to be the case since you say that the lights for the HD, CD-ROM drive, and KB are not coming on.

Welcome to http://www.pcguide.com/ubb/pcgubb.gif

I agree that it sounds much more like a power problem to me than a motherboard problem, but the computer guy can make more money selling you a new motherboard than a power supply. If you can get the power going and it still has problems, let us know since there are a number of steps you can take to test the motherboard before giving up on it.

The easiest way to check if the power supply is the problem is to try a known good power supply and see if the computer boots up.

Budfred

Hello smahar.

My diagnostic charts may add a point or two [they were not designed for ATX systems].

START UP
1. Is the PC dead? Yes.
2. Got to SYSTEM test.

SYSTEM
1. Does the fan run? No.
2. Are the power supply voltages correct? If they are then the fan in the PSU is faulty.
If they are not then disconnect all peripherals adaptors and the system board.
3. Does the fan now run? If it does not then your power supply is faulty [non-ATX system].
If it does run then:
4. Re-connect the system board. If the fan does not run then the system board is faulty.
If it does run then:
5. Reconnect ONE device. If the fan does not run this last device is faulty. If it does run then:
6. Are all devices connected? If they are re-test the system. If they are not then repeat from step 5, adding one device at a time until all faulty devices are found and excluded and all good devices are connected, then re-test the system.

Hi Sylvander,

Sorry for the slight off-topic question

Do have a diagnostic chart that can be emailed, this is a cool idea as my memory is not that good and I forget things to test? I am having a somewhat similar problem with my devices, my secondary controller is not reading know good devices or if it does it takes forever to recognize them. I am having a time remembering what to test next. This flow chart would be a great idea in system testing. If you don't mind I would like to get a chart like this.

Many thanks

Ron

I wish, I wish, I wish Ron, that I could but I cannot as things stand.

1. The charts are on paper and I have no scanner.
I tried again asking my wife to use Word to make charts in doc files using the paper copies as a guide and she's understandably reluctant but says she might try do complete them over a longer period.
2. They are not up-dated to cater for ATX systems.
Perhaps if I did produce them someone would update them.

There are the following test charts:
START UP
SYSTEM
DISPLAY
NO POST
BOOT UP
HARD DISK DRIVE
FLOPPY DISK DRIVE
SERIAL PORT
PARALLEL PORT
POWER SUPPLY TEST

What they do is give you a systematic way to home in on the likely cause of a problem by giving answers to key questions.
You start with a general chart and it tells you to go to another chart and possibly a third.
It will give possible causes along the way.

Everyone who would like a copy should send me their e-mail address and I'll put them all in a folder marked "Charts" and send out copies if they ever get made.

Sylvander,

Many thanks, if you do get them together my email address is:

email address removed.

In the mean time I am going to try to put one together myself from what I know, maybe that will help me to remember.

Kind Regards

Ron

It's not such a good idea to publish your e-mail address like this, you should have sent me a private message enclosing it.

I'll put your address in the special folder in my address book [you're the second].

to spell it out:
The address is rgrosenwald at yahoo dot com [since you've already published].

Thanks every one for the reply. Thanks budfred for the welcome. I am grasping all the replies in. About my computer:
Intel 200 MHz Pentium Processor w/MMX technology.
Casing: ATX midtower with 200 watts powersupply
MB: LAWMAN (Part#: MBDSAC092ABWW)

I don't have a voltmeter at home to do the recommended tests. I may have to buy one. By the way I bought this comp. 6 years ago from gateway. So the comp. guy who tested this was from gateway and he said that they don't have this motherboard any more and his recommendation was to buy a new computer which he said may cost approximately 500 $ or to replace the MB if I could find one.

smahar.

If you can borrow or even buy a power supply to try instead of the one in there now, you can determine if that is the problem without a multimeter. If it does turn out to be a bad motherboard, you can replace it with a compatible one for very little, if you are willing to do the replacement. However, it sounds like the tech wasn't as interested in fixing it as he was in getting you to buy some more equipment. If you can test the power and it still isn't working, let us know and we can give you whatever suggestions you might need to replace the motherboard or the whole computer.

Budfred

Hello everyone,

I tried to boot the comp. for the first time since it was brought from repair shop. I noticed that the CD LED comes on momentorily. However, like before, it does not read the floppy drive (no LED comes on). No power to the keyboard. Monitor stays at amber (monitor is connected to the power surge). Fan at the PSU works. Does this tell that the PSU is OK?

Sylvander: Mine is ATX according to gateway. Also since fan at PSU works, I can't use your diagnostic chart right? do you have another one appropriate to my situation?

smahar

It makes it more likely that the PSU is not the problem, but it still could be. How extensively do you want to get into trying to sort this out? The next step I would do is take the board out and do a minimal boot on a nonconductive surface.

Budfred

Budfred,

I am eager to solve this problem. Can you explain a little more about 'Take the board out and do a minimul boot on a non conductive surface'? Thanks a lot .:)

smahar

First disconnect all of the drives and then you have to unscrew the motherboard from the case, but keep the power supply connected. Set the motherboard on a piece of cardboard or wooden table so that is won't short out when you test. Keep the power switch connected too (there is a way to start without it by briefly touching the power pins with a screwdriver, but it is easier to keep it connected to the power switch).

With only the CPU, power, video, keyboard and one stick of RAM, try turning on the system. If it POSTs, meaning that it starts to boot and gives at least a beep, then the CPU and board are probably ok. If it shows something on the monitor, it means the video is also ok. If it doesn't POST, either the motherboard, CPU or power supply is bad. If your fans in the power supply and on the CPU are running, it means that the power is probably ok and that leaves the motherboard or CPU. The only way I know to test them is to find a known good compatible system and test the CPU in that motherboard and/or test your motherboard with that CPU.

Hope this helps, let us know if any of it isn't clear.

Budfred

Budfred,

Thank you for the reply. I will try this.

smahar.

Hello smahar.

You said: “I can't use your diagnostic chart right?”
Yes you can. It is still of use but you need to bear in mind the things which would not apply.
Others may alter it to suit ATX PC’s and give me a copy I hope.
If that happens quickly you’ll be in luck.

Well I got them finished quite quickly as it turns out and have sent copies out to various people.
The files occupy 814 kB but one person’s ISP reported a failure to deliver because AFTER COMPRESSION the e-mail total was 1,146,062 Bytes! GO FIGURE!
Another problem has been that some people have their e-mail client’s security settings set to block files that COULD include a virus. I assure you these do not. Outgoing e-mails are checked by AVG.
I could send them one file at a time if necessary, but it would increase the difficulty since I’d need to devise a system to keep track of it all.
Send me an e-mail address [not necessarily your personal address] in a personal message and I’ll send them there.
They were made in “Microsoft>Office 97>Word>File>Page Layout” and should be opened, I believe, in this or better [remember to use the “Page Layout” view or you’ll only see the text heading].

Budfred,

I did a minimal boot. When I first turned on the computer, Power LED came on. Fan at PSU was working. No power to Keyboard. Monitor remained amber. I then turned off the computer and turned it on again. After doing this 3-4 times, i believe it's the fifth time I heard the beep once. Fan was working. There was power to the keyboard. Monitor displayed the following:

"A:Drive Error, Press Esc to resume"

Pressing esc did not do any thing. I turned off the comp and turned it on again and again (was trying my luck :rolleyes: ), nothing happened expcept for the fan.
What could be wrong? :confused: :confused:

By the way, I see the fan at PSU. Is there another one? You said:
"If your fans in the power supply and on the CPU are running, it means that the power is probably ok..."

If every thing is OK should I also see the LED on floppy and CD? I did not see those lights coming on either.

smahar.

Sylvander:

Thanks. I did the math. I don't have the luxury of getting a big email right now. I need to ask my significant other if i can use his/her email address.

smahar

O Budfred,
I didn't mean to put that blue face. it was an accident. The error message was
"A : Drive Error, Press Esc to resume"

smahar

It makes sense that you had an A: drive error if the A: drive wasn't hooked up. It doesn't make sense that it booted once and not other times. This brings us back to the power supply. Power supplies can die slowly compared to CPUs and motherboards. Usually if either the motherboard or CPU is dead, you won't get POST and certainly won't get as far as you did. We are back to trying to find another power supply you can try to see if it will work with a known good power supply.

I said fans because most computers these days have several, particularly on the CPU. However since you have 200Mhz Pentium, it is possible that you do not have or need any additional fans.

The good news is that your CPU and motherboard are more likely to be ok, the bad news is that you will need to find out if your power supply is bad.

Budfred

My old P150 had a fan and so did my AMD 200. Are we sure that there isn't one on the processor?

If the power supply IS bad, I would try to think twice about replacing it unless it was at or near free. What are the rest of the specs of the pc? A 4x CDROM? pc66 memory motherboard? Surely usable but watch how much you end up putting into them. Look at what the rest is prior to spending much

Hi,

Thank you for the replies.


I could not use the internet for last couple of days because of the recent virus situation. I am back now. I will look for a used power supply. When I look for one what are the things that I should consider? My current ps says 200 Watts Max on is surface. Further a bunch of wires comes out of ps which go to each of the drives and MB. When I buy one, does that come with all these wires and connectors? What is the price range?

Ted:

I did not understand your comment because if the PS is bad then only thing I need to buy would be a ps right? Why worry about cdrom and stuff? I use this computer to surf the internet, send/receive emails, and babysit my 3 year old (She mess around with it for hours) Here are my PC info:-

P55C-200 Pentium Processor and MB
Mitsumi 12x/24x cdrom

I would urge you to get a new power supply rather than a used one. Power supplies can be tricky and a used one may give you more grief than service. If you are in the USA, I have gotten a couple of decent Allied power supplies for a good price and you can get by with probably only 250 watts on that system. I would go the extra just to avoid any other problems in the future.

I think what FTT was trying to say is that your system is obsolete, so be careful about how much more you invest in it, it may not be worth it.

Budfred

Edit:

Sorry, I forgot to address your main question. If you have an ATX board in an ATX case you will want an ATX power supply. It should come with the right connections and probably more connections than you will actually need.

Budfred again

Hello smahar.

You say your fan is working.
A clue!
Hence:

START UP TEST
1. Is the PC dead? No. [There is a fan running]
2. Did POST appear to run? No.
3. Were there any audible beeps? No.
4. The Power-On Self-Test failed to complete. [NO POST]

NO POST
1. Are the PSU voltages correct? Check them if you can. If they are not you may have a faulty PSU. Assuming they ARE ok then:
2. Disconnect all peripherals and system adaptor cards except the keyboard and video card/monitor.
3. Does the POST now run? If it doesn’t then your system board [or something on it (video card, CPU, memory)] is faulty. If it does run then:
4. Re-connect the floppy disk drive and run advanced diagnostic software from a floppy disk. Get “TuffTest-Lit” from http://www.tufftest.com/free.htm, or better if you can. This is simple and basic.
5. Does the system board pass? If not then it is faulty. If it does pass then:
6. Switch of and re-connect ONE peripheral/adaptor card.
7. Does POST now run? If it doesn’t this last device connected is faulty and should be disconnected. If it does run the device should be tested using the diagnostics and if it fails is faulty and should be disconnected. If it passes it's ok and should be included.
8. Repeat from step 6 until all devices are tested, all faulty are excluded and all working included, then re-test the system.

You also said that one time POST succeeded at the fifth attempt.
When once I had an intermittent failure to complete the POST it turned out the cause was an old and failing CPU FAN.
The fan would make screeching & and howling noises at start up.
I suspect that it was intermittently shorting the power supply.
If I kept trying it would eventually POST.
I replaced the heat sink and fan and the problem magically disappeared and has never since returned.

Hi,

I bought a new powersupply; CompUSA 250W ATX (25$). I found that this one doesn't fit in my case!! Anyway I tried it without mounting it in the case. Comp. did not boot. So now I suspect the motherboard may be bad. But the thing I don't understand is that the computer booted once randomly with my old PS which suggested that MB and CPU are probably OK.

A manual came with the computer showed the location of the reset button in the Mb. there were no any buttons. rather they are two pins. i touched them with the end of a screw driver to reset. I don't know whether it is a right thing to do. Any way, it did not help either.

If the MB is bad, what are my options now? Does the whole computer go to the Junk yard? Obviously there is nothing wrong with the case or monitor. If I am to build a new computer, what are the components that I can save?

Thanks, Smahar.

Does your old power supply have a place on it to plug in the monitor?? If so, it is an AT power supply and I am not sure if your motherboard will work with an ATX power supply. Actually, I am not even sure it will plug in properly. Given the age of the system and the fact that the ATX power supply didn't fit, I would bet it is an AT board in an AT case with an AT power supply. If so, I would try an AT power supply before giving up.

Also, I haven't heard of ATX boards with a reset button (doesn't mean that they don't exist, I haven't been building that long), but this would further suggest the AT option. If it is a typical ATX Clear CMOS jumpers, there should be 3 pins. I am not sure shorting them would work either.

As far as what you can use from that system, if it is AT, you will probably be pretty limited. Floppy and other drives, maybe a little RAM. Of course if you want to use things in another AT system, more would be usable.

Thanks for the prompt reply. I found that my board and case is ATX through Gateway customer service rep. I confirmed this by an independant second call to GW customer service. Is there any other way of determining this?

smahar.

If it is an ATX case, it should be able to handle an ATX power supply. AT power supplies have the plug for the monitor, so if it is AT, it should have that. If it is ATX, you might want to double check that power supply install. Of course, it could also be a proprietary case from Gateway, but they should have been able to tell you this. A mystery this is.....

6 year old computer??? Has the MotherBoard battery ever been replaced??