After a sudden blackout, the computer does not turn on. The computer does not turn on after turning off the lights, help

The computer does not turn on after turning off the lights, help!

First, try to sniff to see if there is a burning smell from the power supply unit (PSU).
If there is no smell or you cannot hear it, do the following:
1) Pull out the power cable from the computer (the one that goes into the power supply) and insert it back, and do the same where this wire is connected to the outlet.
2) If it doesn’t help, open the system case and take out the small round battery on the motherboard, and then try to start the computer without it in a couple of minutes.
3) If it doesn’t help, try to remove everything unnecessary from the computer, without which it will be able to work. For example, leave only one RAM, and remove the second stick if there is one, remove the network card, sound card if there is one, hard drive and video card. Try starting your computer without them.
4) If all else fails, put everything back in and pull all the connectors inside the system unit and all the wires going into the system unit and into the socket.
5) If it doesn’t help, borrow any power supply from a friend and try to start your computer with it.
BP died. In general, when a computer that previously worked normally suddenly stops turning on at all (i.e., after pressing the button, absolutely nothing happens, stupid silence), then the reason is almost 100% in a dead power supply
The power supply is probably burned out

If the computer does not turn on, this does not mean that something in it is necessarily broken or that you need to call a specialist, open the case, etc. The computer does not turn on for other reasons. Let's, according to tradition, look at this point using several examples from practice.

I’ll make a reservation right away: everything that will be described below should be considered as the simplest version of the situation when the computer does not turn on. It is very likely that the reason for this may lie in something else:, or something else. If you have, then we also have an article for this case on our website.

Here I want to talk about the fact that behind all these harsh “hardware” problems, people sometimes do not see the most basic and obvious things, and if the computer does not turn on, they can do a lot of unnecessary and unnecessary work.

First, let's look at the most common case when the computer does not turn on, which plunges the average user into a catatonic stupor and forces him to press the “power” button to no avail, and then call the technician :) This happens at our work regularly when there is a sudden power outage.

The master comes, puts one hand behind the system unit, does something there and “the car starts.” The user is happy and happily distributes inexpensive candies and cookies :)

At certain intervals after The lights go out and the computers don't turn on.. Let's figure out why this happens. At the moment of a sharp drop in voltage, the power supply protection is triggered. The voltage drops quickly, but due to the capacitors in the unit itself, it does not drop quickly enough for the protection not to react.

Note: A high-quality power supply has different degrees and types of protection. Here are the most common ones.

OCP (Over Current Protection): against power surges;
OVP (Over Voltage Protection): against power surges;
OPP (Over Power Protection): overload protection, sometimes called OLP;
OTP (Over Temperature Protection): against overheating;
UVP (Under Voltage Protection): against low voltage;
SCP (Short Circuit Protection): against short circuit;

In this case, the computer does not turn on due to the protection against power surges. It turns off the current flow through the power lines. This occurs by charging a special capacitor of the protection circuit, which, when charged, does not allow the system to turn on. In order for the system to turn on, all we need to do is pull out the power supply cable (220 V) from the power supply for 3-5 seconds and plug it back in (we will discharge the corresponding capacitor).

Thus, we “reset” the protection of the power supply and it can continue to work.

This is what they call a “classic of the genre” :) Now I would like to talk to you about more atypical cases when the computer does not turn on. In my practice, they met several times and I thought that this was quite enough to talk about this possibility.

So, let's begin the “memory session” :) On one of the working office machines, a USB mouse was installed with the following adapter to the PS/2 port:

Apparently this same adapter, over time, began to cause a local short circuit (short circuit) in the connector, which automatically triggered the corresponding power supply protection circuit. As a result, the computer did not turn on, it did not turn on at all. It is not clear who connected the mouse through the adapter and why, but after connecting the device directly to the USB connector, everything worked fine.

So - keep that in mind.

Another example: the management department calls - " The computer won't start". I come - it really doesn’t start. I try a couple of them, which I usually sort through on the spot. No result. I take the system unit to our IT department for a “debriefing” :) I only take the “box” itself (without cables, keyboard and mouse) I bring it to my place, connect cables and input devices - everything works!

Using the trial method, it was revealed that the reason that the computer did not start was a non-working keyboard (more precisely, its microprocessor). The keyboard has been replaced. It happens that when the keyboard is not working, the internal system speaker emits three short beeps in a row.

And here is another case from my practice. A security guard from our work brings his home PC and says: computer won't turn on, I don’t know what the reason is, please look. Why not help a good person, let's see!

I bring it into my office, take it out of the box, put it on the table and do an initial visual inspection. What should I tell you? I'd rather just show you a few photos:

What was the man doing with the car!? And this mysterious phrase of his: " won't turn on, don't know why?..." :)

What do I want to draw your attention to by giving these examples? When diagnosing, try to consider all possible options. Think more broadly, do not focus only on some “standard” list of faults. If the computer does not turn on, first disconnect all its external peripherals and input devices, what if they are the reason? Well, if the computer is not yours, do you take into account the degree of technical adequacy and literacy of its owners? :)

I sincerely wish you good luck in this painstaking task!

Question: The computer does not turn on after a power outage

In our house the electricity is often cut off, and then I can’t turn on the computer for a long time, I don’t understand whether it’s a problem with the power supply or with the power button. If the problem is in the button, then what can I do to make the contact better? If PSU, then what should I replace it with (mother gygabyte 915P GA-81915PC Duo) and what UPS should I take?

Answer: It happened like this: the lights were turned off, when the lights were turned on, I decided to turn on the computer, pressed the button and suddenly the cooler started spinning, the lamps lit up, the hard drive and the video heater got hot, in general, everything worked, but on the monitor there was nothing, just a dark screen and I solved the problem as follows. Turn off the computer, open the cover of the system unit and look for the chassis jumper on the motherboard, pull it out of position 1-2 and insert it into position 1-3, turn on the computer after a minute, turn it off, move it back to position 1-2 as it was, turn on the computer and EVERYTHING worked!!!

Question: After a power outage, the RAW system on the disk

After a power outage, one of the screws on the computer went sour. I use it as a media center, watch movies on TV from it, download everything to it. The first call had already happened before, there were recording errors, the checkdisk helped, bad sectors were found, I thought it would live, but somehow it quickly died...

Before I read this topic I had already tried different options. I tried chkdsk /f. Did not help. testdisk scanned, but did not correct anything.

What’s interesting is that there are 2 identical screws in the computer; the soured one always had a lot of information, movies, games, etc. stored. And the second one was practically not used, well, you don’t need so much space. 33 gigs out of 2 TB was the maximum that was used. Moreover, according to SMART, he has the same condition as the first one. And during scanning there were also bad sectors.

But it still works and there is no important information on it, but I would like to get photos from the first one, everything else can be downloaded again. Tell me what I can try? Thank you!

Answer: Someone please advise something useful...

Question: The network settings in the printer are lost due to regular power outages. What can be done?

Hello.

At work I have an HP LaserJet 400 M401dn network printer, which, apparently due to power outages, loses the manually entered network settings (IP, mask, gateway) and, as a result, it becomes impossible to print on it. In the hope of stable operation and exchange of information, I gave all computers on the network a fixed IP, as well as the printer. How to overcome the described failure in the printer settings, so that even after a power outage you can always print on it?
I found two interesting points in the troubleshooting instructions:

2. If you installed the product using the HP standard TCP/IP port, select the Always print from this printer, even if the IP address changes check box.
3. If the device was installed using a standard port for Microsoft TCP/IP, use the host name rather than the IP address.

They seem to contain a hint of an answer, but it’s not enough for me.
2. What is the standard HP TCP/IP port?
3. How can I check whether the device (as I understand the printer) was installed using a standard port for Microsoft TCP/IP? Is this checked on a computer or in a printer?

Answer: The answer to the second question is absolutely obvious: look at the properties and name of the port; Regarding the first question - if in 3 weeks you haven’t found 10 minutes to Google the answer - wait until more active participants have free time to copy-paste you the answer from the Google page to the topic page.

Question: Started freezing in games after a power outage

The power went out while playing Battlefield 1, after which, when I turned on the computer and entered the game, artifacts began to appear. I decided to reinstall the drivers for the video card. The artifacts are gone, but friezes have appeared. I would like to know what the problem could be. Please tell me. Fps drops from 120 to 9 instantly

Answer: Maybe try reinstalling Windows?

Added after 1 minute
The first time I logged in after shutting down, yes, there were artifacts, after reinstalling the video card drivers they went away, but in the middle of the game they started freezing for 3-4 seconds

Question: After disconnecting the router, the Internet connection is not restored

Good luck to everyone. In general, after disconnecting the router, the Internet connection is not restored...
On the right, below, the icon is lit - without Internet access.
Although it goes into the router settings without any problems.

The only way to restore the connection is to reconnect the twisted pair cable in the PC.

Tell me why the connection may not be restored and what to do?

Totolink N300RT router

Answer:

Message from CrusherHeads

The router cannot work after disconnecting

Most likely, the operating system cannot connect to the router.

Added after 3 minutes

Message from CrusherHeads

distorting twisted pair cables in a PC

In the topic "Wi-Fi, wireless networks".

Question: Selecting a UPS that turns on when power returns

You need a UPS without any software. The only thing that is needed is that after turning off the electricity, completely discharging the UPS and then returning the electricity, the UPS turns on and supplies current to the computer. Those UPSs that I have, after a complete discharge and return of electricity, require you to hold a button on them and turn them on manually, and this is not convenient. Tell me, thanks in advance!

PS. We need the cheapest ones

Answer: These uninterruptible power supplies, which I used to buy in large quantities - "IPPON Back Office 400", definitely do not return online on their own. When I found out this, I began to buy Cyberpower uninterruptible power supplies. They came back online when the power came back, but one day it didn't happen on one important server. So I started searching and asked the question here. But when I then did a test of the uninterruptible power supply on that server (Cyberpower was installed there) - I could not reproduce the problem - for some reason the UPS came back online. But despite this, just in case, I followed the advice here and bought an APC, this one - “APC Back-UPS BX650LI”, because this is the cheapest APC that I found. And in the future I will buy this brand just “just in case,” because even one case of non-return causes great inconvenience. But APC is of course more expensive.

Question: acer v5-551g (DAOZRPIB6B0 REV: B) does not turn on after turning off ram

This laptop came to me after an unqualified repair. The memory has been removed from it, and all legs of the SPD are sealed off from the board. However, it does not start. If you solder the SPD legs, there is a start, but there is no boot from any device, neither in legacy nor in UEFI. After reading the forum, I realized that a modification was made so that the laptop would boot from devices, but it was done crookedly. I would have done everything right, but the R613-R614 nickels were torn off. There are no normal service centers, because I live in a small town. His hands are still in place. Tell me what to start doing and in what order?

Answer: yes, I understood this, and that they are for switching ram, I also understood this, only my nickels were torn off (you can see in the photo), I realized that the resistors there should be 10 kOhm, but I don’t understand how to determine where these contacts from the nickels go, because I can't restore it. Another interesting thing is r614-r613, are they duplicated r626-r625?

Question: PC turns on only after disconnecting from the network 220

Hello.

I have this problem. I was playing a game, the computer froze, the blue screen of death popped up,
After that the download started and the computer rebooted.
I go back into the game and everything happens again.
And from that moment on, when you restart the PC, the fans are still humming as usual,
but the monitor is black. I turn off the power 220. I press the ON button and the computer is completely de-energized.
I turn on 220 and the computer boots to Windows and works fine.

Sometimes when I reboot, Windows appears and then freezes (black screen, instead of logging into Windows)
Only complete disconnection from 220V helps.

Answer:

Message from HotBeer

max1488, there are “jokes” with the electrical circuit, that with a certain power supply and electrical circuit, the computer can turn on or not, of course you won’t change the wiring, but you can try with another previously working power supply.

Initially, the joke started with the fact that a blue screen appeared... then the computer stopped turning on after a reboot, and then after sleep mode it went out. (The MB has cooled down?) How then is it understood that if the problem is in the “power supply”, then why did the computer start working after removing the battery?

I'm sinning on the hard drive or processor.

Now the computer rebooted 6 times normally without glitches)
but it is worth putting it into sleep mode. It can only be removed from there by removing the battery.

Added after 8 hours 27 minutes
Is it only the power supply that can screw up like this? Are other options excluded? with the process

Added after 4 minutes
Tell me, what program can I use to check the Processor?

Added after 2 minutes
and what to look for? what is the optimal temperature for the processor?
intel pentium 4 3.2