0

I have set up a new motherboard on an old chassis of a desktop PC. The mb has its own embedded GPU, and I haven't added any additional graphic card. I have connected the mb to the PSU through the 24-pin EATXPWR ATX power supply plug (I couldn't find out of the PSU any 4-pin connector to plug into the mb's chassis-fan plug). When switching on the PC, both the chassis fan and the CPU fan start working, but the monitor doesn't receive any signal. The monitor itself is working on other PCs. I am a bit lost about what steps to take before sending back the mb go the seller.

I have also followed without success the suggestions of the answer below by user3797758:

  • I cleared the RTC ram
  • mb is Asus B150M-C and looks perfectly compatible with CPU which is Intel Core i7-6700 (the CPU itself is shipped with Intel HD Graphics 530)
  • I have tried connecting the pc to a HDMI monitor as well as to a different VGA monitor. Both monitors work well with the same cables, therefore the problem should not be there.
5
  • 1
    1. Sometimes poor contacts on RAM may also result into this behavior. Try reinserting the RAM sticks. Clean the RAM slots and retry. 2. You might have missed CPU EPS connector. Have you also plugged in the 4 or 8 pin CPU EPS Power Connector in addition to the 24 pin ATX on mobo? 3. You mentioned about PSU not having 4 Pin fan plug. How does the socket for that on mobo look like? Is it 4 Pins in a row or two sockets above & two below?
    – patkim
    May 7, 2016 at 19:29
  • Remove the power cord from the PSU and then hold the power button for about 1 minute, then re-plug the power cord and turn on the computer. See if the problem is resolved.
    – iSR5
    May 7, 2016 at 20:08
  • @pat2015 yes I found that the PSU 8 pin plug could be slided and divided into 2 4-pin plugs, and one of them fitted into the mobo's ATX 12v slot. I have also reinserted the RAM sticks but monitor still sleeps. Should I press the DEL key? Is it a problem to use a USB wireless keyboard?
    – perissf
    May 7, 2016 at 20:22
  • 1
    Run with very minimal components, just mobo CPU & PSU. Disconnect all other peripherals including keybaord, mouse, HDD. Also conduct a run without RAM, if your CPU is running & you have built in speaker in cabinet connected to the correct pins on mobo you should hear some beeps. With keyboard connected do NUM / CAPS key LEDs respond when you press those keys even if there's nothing on Display?
    – patkim
    May 7, 2016 at 21:18
  • @pat2015 after following your suggestions I made it! Removed all components, added one slot of ram (without ram it didn't start ) and worked. Then I added back all components one at a time, and it always succeeded, so I don't know where was the problem, but it works and it's enough! You can post your comment as an answer
    – perissf
    May 8, 2016 at 13:25

2 Answers 2

2

If newly assembled or modified desktop PC appears to have started (Fans, LEDs running etc) but does not display anything on screen, try the following.

  1. Ensure that all connectors are firmly attached to the respective components.
  2. In addition to 24 Pin ATX also make sure that 4 or 8 Pin CPU EPS power connector is firmly connected to the respective socket on the motherboard
  3. Run the system without RAM. If cabinet speaker is working & CPU is working you should hear some beeps indicating missing RAM. It also indicates that CPU is running the firmware
  4. Now start the system with bare minimum components, just one RAM stick if you have more than one, CPU & PSU. Try inserting/re-inserting RAM, if needed clean the RAM Contacts & RAM slot as it may help improve the firm contacts of all Pins. Sometimes this behavior is exhibited if all RAM contacts are not making firm contact with respective pins in the slot. Switch between RAM sticks if needed.
  5. Then try adding one component at a time and test if it starts now

Above steps worked for the user in this case. However any issues with PSU or motherboard / graphics or even CPU can not be ruled out as well. Even make sure that motherboard is not accidentally touching the cabinet.

1

some common things that you can try doing:

  1. Reset the CMOS, look in the instructions of the MB for how to do that on you specific model
  2. Try different video out ports, so if theres VGA, HDMI, Display Port, try those...
  3. Try a different cable, the one that your using to test with might be bad.
  4. Depending on the MB and CPU combination the MB may need the CPU to have the integrated GPU (many Intel CPUs are like this). So check that the CPU has this integrated.

Try these and comment bellow on what happens :)

btw, the PSUs fan is controlled by the PSU itself, you don't have to plug it into the MB

1
  • Thanks for the suggestions. I have tried them and updated my question accordingly
    – perissf
    May 7, 2016 at 19:26

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .