F5F Stay Refreshed Hardware Desktop Dell OptiPlex fails to power on while PSU and CPU fans exhibit erratic behavior. Assistance needed!

Dell OptiPlex fails to power on while PSU and CPU fans exhibit erratic behavior. Assistance needed!

Dell OptiPlex fails to power on while PSU and CPU fans exhibit erratic behavior. Assistance needed!

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seirey
Junior Member
4
02-26-2025, 07:48 AM
#1
Hi, your Dell OptiPlex 7040 was installed into a different cooler case. You managed to get the power button and all necessary components working, but it still won’t turn on. The fan is making a faint noise, yet there’s no power. Both of your power supplies are functioning correctly, but the system remains unresponsive. It seems there might be an issue with the motherboard itself. I’d like you to double-check before spending more money on a new board and CPU. Your Movie 1.mp4
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seirey
02-26-2025, 07:48 AM #1

Hi, your Dell OptiPlex 7040 was installed into a different cooler case. You managed to get the power button and all necessary components working, but it still won’t turn on. The fan is making a faint noise, yet there’s no power. Both of your power supplies are functioning correctly, but the system remains unresponsive. It seems there might be an issue with the motherboard itself. I’d like you to double-check before spending more money on a new board and CPU. Your Movie 1.mp4

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Butterfly1416
Senior Member
701
02-26-2025, 09:18 AM
#2
It seems like the issue might be simple. Remove the board from the case and check connections. Verify everything is properly aligned and attempt to power it on. If it starts correctly, contact might be missing somewhere between the case and board—consider adjusting or modifying the case if needed. Try connecting it to the original power supply to see if it works. If it still fails outside the case, you may need to return it and replace the adapter.
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Butterfly1416
02-26-2025, 09:18 AM #2

It seems like the issue might be simple. Remove the board from the case and check connections. Verify everything is properly aligned and attempt to power it on. If it starts correctly, contact might be missing somewhere between the case and board—consider adjusting or modifying the case if needed. Try connecting it to the original power supply to see if it works. If it still fails outside the case, you may need to return it and replace the adapter.

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ISY_0815
Senior Member
566
02-26-2025, 11:09 AM
#3
Welcome to the discussions! Aisle holds the responsibility. Work outside the enclosure and diagnose there. I think there might be a bad PSU or a short circuit, so you've probably tried jump-starting the power supplies using the paperclip method to check if it even powers on. You could also attempt booting without the GPU to observe whether the PSU's output is decreasing. Does the motherboard lack a standard 24-pin connector? I assumed they didn't have a custom power interface...
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ISY_0815
02-26-2025, 11:09 AM #3

Welcome to the discussions! Aisle holds the responsibility. Work outside the enclosure and diagnose there. I think there might be a bad PSU or a short circuit, so you've probably tried jump-starting the power supplies using the paperclip method to check if it even powers on. You could also attempt booting without the GPU to observe whether the PSU's output is decreasing. Does the motherboard lack a standard 24-pin connector? I assumed they didn't have a custom power interface...

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CCS2001
Junior Member
21
02-26-2025, 03:12 PM
#4
I'm not sure how to jump start the PSU, but I understand they function. It's an unusual 8-pin proprietary design from Dell, and I have an adapter to use a 24-pin ATX PSU. I'll follow what Aisle suggested and reach out to both of you again.
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CCS2001
02-26-2025, 03:12 PM #4

I'm not sure how to jump start the PSU, but I understand they function. It's an unusual 8-pin proprietary design from Dell, and I have an adapter to use a 24-pin ATX PSU. I'll follow what Aisle suggested and reach out to both of you again.

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Angeli4234
Member
158
02-26-2025, 04:41 PM
#5
I connected my original Dell PSU and it started up perfectly. However, the other two PSUs in the video didn’t work and kept shaking. Once I removed the faulty ones, I noticed they only reacted when connected to the CPU cable, even without the 8-pin power cable. I’m unsure what this means moving forward but appreciate your assistance. I didn’t realize I had the original PSU and I’m glad I didn’t damage my motherboard.
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Angeli4234
02-26-2025, 04:41 PM #5

I connected my original Dell PSU and it started up perfectly. However, the other two PSUs in the video didn’t work and kept shaking. Once I removed the faulty ones, I noticed they only reacted when connected to the CPU cable, even without the 8-pin power cable. I’m unsure what this means moving forward but appreciate your assistance. I didn’t realize I had the original PSU and I’m glad I didn’t damage my motherboard.