Dell Optiplex 3040 SFF keeps rebooting

How does the system work with the i3 6100 CPU installed? I ask because the power draw on the i5 is almost exactly the same as the i3. How much RAM do you have installed and how many drives? 

Re: don't know what to do since it is impossible to use the pc shutting down every 20 minutes

at least pc is able to POST, although it sounds like it has a stability issue.  agree w JOcean that ram is one common source of system instability.

often when users service their pc and encounter new issue they think it is due to the new components such as cpu etc.  sometimes the underlying problem may be corrupted cmos settings that had been dormant for some time.  try replace cmos battery with a new cr2032 then clear cmos settings via motherboard jumper.

The pc works excellent with the intel core i3 6100, I also tried to test the gt 1030 with the i3 but the same thing happened, the pc would reboot, I have both memory slots occupied, each one has a module of 8gb of ddr3l ram at 1600mhz , for a total of 16gb of ram, and the consumption of i5 similar to i3 makes it even rarer, for example, when I played gta 5 without a graphics card and with my i3 the pc was fine, but now after a few seconds playing it with the i5 and the gt 1030 the pc reboots, just like with any other game, https://www.youtube.com/watch?v=syHUVtFRsTw here is a video of a guy using my same settings, and without any problem, so I'm almost sure it's the psu, since the 16gb of RAM never gave me any problems, they are from different brands but they work at the same speed, I don't know if this information is enough so that you help me to find a solution

I understand, I'm going to try to test with a single RAM module to find if any of the 2 is causing problems, if it doesn't work I'll try your solution, do you have any video or guide that shows me how to clear the cmos configuration through the jumper motherboard? thanks, another thing, when i use the pc for normal tasks like browsing google or watching netflix or playing light and old games like gta san andreas or age of empires, it works quite well, however when opening games like gta 5, fall guys and more modern games the pc restarts, in both cases the same thing happened, only using intel core i5, or using i5 with the gt 1030, it never happened before with the i3, could you confirm if it is an energy deficiency? Because the truth is that it doesn't make sense for the PC to turn off just by opening a game that requires a little more power, I'm sorry if my questions are redundant and repetitive, but the truth is my budget is tight, and I invested a lot in this PC and this problem it has me worried.

The pc works excellent with the intel core i3 6100, I also tried to test the gt 1030 with the i3 but the same thing happened, the pc would reboot, I have both memory slots occupied, each one has a module of 8gb of ddr3l ram at 1600mhz , for a total of 16gb of ram, and the consumption of i5 similar to i3 makes it even rarer, for example, when I played gta 5 without a graphics card and with my i3 the pc was fine, but now after a few seconds playing it with the i5 and the gt 1030 the pc reboots, just like with any other game, https://www.youtube.com/watch?v=syHUVtFRsTw here is a video of a guy using my same settings, and without any problem, so I'm almost sure it's the psu, since the 16gb of RAM never gave me any problems, they are from different brands but they work at the same speed, I don't know if this information is enough so that you help me to find a solution

you have provided cpu ram and gpu spec but you may not be aware that hdd and dvd cost power too.  assuming you have 1 sata hdd + 1 sata ssd + 1 dvd rw, basic psu calculator for

• i5-6500 alone

Load Wattage:178 W

• for i5 and gt1030

Load Wattage:209 W

so it does seem the i5 with gt1030 is overloading the 180w psu causing crash/restart.

compared to

• i3 alone, 180w psu is safe and happy. it explains "The pc works excellent with the intel core i3 6100"

Load Wattage:165 W

• i3 + gt1030, 180w psu too weak again. it explains "I also tried to test the gt 1030 with the i3 but the same thing happened, the pc would reboot"

Load Wattage:196 W

some suggestion:

disconnect sata power to hdd and dvd, only use sata ssd,

• i5 + gt 1030

Load Wattage:167 W

try the above config (if you have OS and game installed on a ssd), if pc becomes stable during game, you are all set and no need to upgrade psu.

what you just told me makes a lot of sense, I hadn't thought of it, this is a bit reassuring for me since it is possible that I don't have to change the psu, a possibility that the font may be fine and the real problem is my exaggeration power consumption, ok, maybe you can help me calculate the watts and see if it is possible to use my configuration, I would remove the cd player and the mechanical disk, so without these things, this would be my current configuration: intel core i5 6500 at 3.20 GHz, nvidia geforce gt 1030 2gb gddr5 graphics card from the MSI brand, 2 ram memory modules each of 8gb ddr3l, for a total of 16gb, an ssd data of 480gb, two 60mm fans, one is the one in the tower , the other is the processor, a wireless network card that goes into the smallest pci port (I don't know what it's called), and a 20-inch led monitor, that would be all that is in my PC, the 180w are enough? How much would you consume all of that? And in case of exceeding 180w, by how much is it exceeded, is it an acceptable surplus? I await your response and thanks for the help so far good man

no need to be concerned about fans network card or led monitor.  just use basic psu calculator.  167w is the estimated load wattage for the config, which is the max system may consume in typical real world scenario including gaming. as long as you do not run stress test on system, 180w psu should be all right. having said that, it is recommended you try this config and see yourself.  If you still had issue with that config then a psu upgrade would be warranted.