Power problem??

My computer runs just fine at certain times of the day, such as late afternoon and evening. In the morning and around noon if I'm on the computer, it will just die like I unplugged it. The only way I can get it turned back on is to unplug the power cord so the thing resets itself. Would you say this is a power problem and would a surge protector keep the computer operating? The power company says it has nothing to do with power source.

Thank you

Running Windows XP on a Athlon750 with 256 MB RAM and 20 G and 40 G HD.

 

I can't tell you why it cuts off at those times. But I can tell you why you have to unplug.

Many motherboards today maintain 3 volts in order to better handle wakeups for LAN or modem etc.

I will hazzard a guess that either you have load managment on you eletrical power or you are on a circut with some large Mfg plant that does something at those hours to cause a brown out.

Put it on a filtered UPS.

Mike

 

rogi , I'll have to agree with the power company. It isn't related to your power source from them. Let's face it, how would unplugging it and replugging it affect the power they are delivering to you? No way.

You have some obscure problem that is likely to be within the power supply of your computer. It sounds like you may have a thermal related failure that occurs when the power supply reaches a certain temperature. There are other possibilities of course. Could be the video card overheating.

Thermal intermittent problems are often hard to track down but any good technician can nail it right away. Bench techs use electric hair dryer guns and freon spray to pinpoint the source of the problem. You'll likely be needing one soon. This isn't something the ordinary user can fix. Take it to a tech and if you explain it properly, it'll not cost all that much to repair. Your insight can save him a lot of time and that means less dough you have to pay.

 

Thanks for the advice mflynn & Zephyr. This is the reason I ask BBS because of the prompt knowledgable answers.

 

Clarification of my last post.

I also agree with the power company. That they are providing a stable flow of juice. But that will not stop a small brown out from some close by large industrial electrical process on your circut when it kicks in.

Or as I said if you have load managment on your home. I can tell when my load management kicks in because my UPS beeps at that time everyday.

It is possible that you have a marginal power supply, therefor it has very little tolerance for these small brown outs.

But these have nothing at all to do with the need to unplug. This is designed into those motherboards today that have advanced wake up features.

There is a controller chip for this that maintains 3 volts to the motherboard when the computer is off. Only certain of the newer boards have this feature.

In an abnormal power down it senses the computer to already be on even though it is off. The remedy is to kill the 3 volts. Then the computer will boot.

As an aside. Many people including myself have switched hardware with the case off and power cord plugged in but the front panel power was off. This is not a thing to do on these motherboards. It has damaged many m/b's and modems and such and sometimes both!

One of the guys that works for me did this a few months ago. He was lucky it only scared him. When he pluged in the modem the computer powered up itself. No danger eletrically to him but he just was not expecting it. And in this case no damage was done.

In order for this to occur the power has to blip fast enough that the M/B powers down but the 3 volts does not. Then you have to unplug.

We have many of the M/B's in use at work. Ever so often we have to unpower!

Mike

 

PS

A small inexpensive UPS should correct this shutting off.

Mike

 

We used to Monitor our Power lines with a Synchroscope (so we could see the variations) , and a Chart Recorder (For Concrete proof for the Power Company Engineers), surprisingly we found out that normally, there are a lot of Spikes on the Power Line. I don’t know how good these H/O PC’s Power supply filters we have are, but we had excellent Filtering on our Main Frame & these spikes still got thru and messed up our Data lines. Our solution finally was that the Power company had to replace pieces parts at a substation that fed us the Power. We had low D-C voltages for the Data circuits and these spikes still sent intermittent false data down the lines, in spite of our Filters. (Thru the D/A Converters)

The point of all this, is since most M-boards have lower voltages running things, it seems to me there’ll be more & more weird Power Supply troubles occurring in the future.

So mflynn is right on his posts "¦Mfgr. Plant nearby causing brownout, or a weak, marginal power supply, and the need for UPS.

 

Thanks a lot for the great info. I am buying a UPS to solve my problem.

Jim

 

Great Info indeed. Thanks.

 

It has been awhile, but my understanding is that a 5 volt signal initiated from the menu option cuts the 120 AC and turns the machine off. This 5 DC volts remains and is continous and enables the push button to turn on the 120 that powers up the PC.

From memory, I believe there is 3.3, 5, and 12 volts output. Just curious has the P/S voltage output changed and the state of art PC doesn't require approximately 5 volts to turn on and off? Is the approximate 3.3 volts all that is required?

 

Hi rogi

This was a excellent question with outstanding responses. I do not have your type of power problems, I still run my equipment through a suppressor. No where near as good as what you will be getting. At my business we do use them (large, multi-battery). When implementing the protective power, just plug in the primary computer/monitor (if networked).. NO printers, scanners, ect. It is a good practice to test the UPS equipment. Two to four times a year, with pc at desktop, all app's closed (good backups always)... pull the plug suppling power to the UPS. This simulates a power outage. Also be prepared to "replace" the batteries every two years or less.
FYI... A UPS is a "fast switch" which provides temporary clean power (via battery) when it is not supplied from the 120 line. Your power problems "might be so poor" that you could be force to take the final step. Equipment that provides "constant" filtered power via the battery. A charging system keeps the battery full charged. This would be somewhat unusal need (and expensive)... but a cure.

 

Ken, You'll enjoy reading this nice explanation of that and much more about power supplies .

It seems that with the appearance of the ATX form came some 3.3 volt CPU's and even some total 3.3 volt MOBO's. Some early ATX's are hybrids using 5 volts and regulating that down to 3.3 where needed. That's poor design and to be avoided (produced lots of heat). The newer ATX's and WTX's are 3.3 volt exclusively and it's supplied directly from the PS without need for further regulation.

Anyway, read that article, you'll enjoy it.

 

I still think rogi's problem may lie elsewhere than with the poor quality of the incoming power but a UPS is a nice addition to any installation. I may get one someday myself.

Rogi, Do you ever get that problem on Sunday when all industrial causes would be likely shut down? Think about that and any other time frame that may be relevant. Also consider ambient temperature as a possible factor and even processor usage intensity.

 

Hi rogi

I know you will NOT like this test, but it would eliminate many of the could be's, maybe's and what if's. Take your computer to someone's house NOT being serviced via the same power provider. If it still acts up, you know it's INSIDE your box. If it doesn't, start with the UPS. Be sure they have a friendly "cash credit" return policy.

 

Zephyr, thanks for the comprehensive link on power supplies. I will have to bookmark for future reference, however, I was able to get an explanation for my question regarding 5V for turning PS "on" and "off'.

SOFTPOWER (power on and 5V standby):

"Early PCs using the PC/XT, AT, Baby AT and LPX form factors all use a mechanical switch to turn the computer on and off. Newer form factors, starting with the ATX/NLX, and including the SFX and WTX, have changed the way the power supply is turned on and off. Instead of using a physical switch, these systems are turned on by a signal from the motherboard telling the power supply what to do. In turn, the motherboard can be told to change this signal under software control. This is what allows Windows to shut the power down to a PC, or what allows such features as turning a PC on from a button on the keyboard. This feature is called "Soft Power" and the signal that controls the power supply is called "Power On ", or alternately, "PS On" or "PS_On.

WTX form factor uses 3.3V. "

Another excerpt, "On newer systems, many components, especially the CPU, have migrated to the lower +3.3V, but many components still use +5V. "

 

I sure wish we would get a yea or nay on this. I'm still betting on it not being a problem with the utility company and doubt that the UPS would have made any difference in this case. I hate to be right and not know it.

Rogi, what has happened to you?

 

Hi Zephyr and all at BBS

Sorry I didn't get back to you. I was on vacation for a while. Yes I did get a UPS and it seemed to help for 2 days and I thought the problem was solved. Then it started the same shuuting down again so I still have the same problem. Trying to live with it until Tax time is over (I do Tax preparations small time). After that I will take it to a technician, I expect I will need a new MB. Thanks for all your help and yes I know people at BBS know what they are talking about or I would not ask for assistance in times of need. Thanks for everyone's great input.

 

Thanks for the update Rogi. I'm sorry your problem persists and hope you don't need that computer for your tax work.

The UPS is still good to have although it didn't work any magic for you this time. Good luck with the bench tech approach. Remember, the more information you supply him, the quicker he can get it fixed; time is money.

Best regards.