Smoke or mist emerging from the PCIe x16 port (note: melted chassis fan wire observed)
Smoke or mist emerging from the PCIe x16 port (note: melted chassis fan wire observed)
The old H110m board stopped working, so I purchased a second-hand Asus ex-b250m-v3 from an online shop. It appeared clean and new. I installed it in the box with an i5-7400 processor and MSI MECH 5600xt GPU, but there was no boot drive. Eventually, it started asking for a boot drive. After reassembly, everything except the 8-pin GPU connector was connected. When I tried to power it on, the display flickered and the PCIe slot released smoke. I removed it right away. The smell wasn’t burnt—it felt more like it had been cooked, similar to when I first got my GPU and used it for a short time. I inspected everything carefully and found no signs of damage. My main concern now is figuring out how to safely test components without causing further harm. Could there be any parts that failed? Also, I’ve forgotten several times to connect the 8-pin on my old board, and it kept refusing to start. Once I finally plugged it in, it worked perfectly. Shouldn’t there be a power limit for the PCIe x16 slot? I’m open to using the PC without a GPU if the PCIe slot is still functional. Parts used: i5-7400, MSI MECH 5600xt, T-Force 3200, CL-16 RAM, 500GB Kingston A400, 1TB WD Blue. Edit added: I was mistaken earlier. Perhaps my first attempt was correct—I ran a second test without the GPU and noticed my chassis fan wire melted. The board itself looked fine, but I had to skip that part. I’m sure it wasn’t a total failure. I’ll rebuild the whole setup from scratch for safety.
The PCIe port typically supplies 75 watts. This amount is sufficient to reach the smoking or burning temperature of grease, dust, etc. It’s likely the store where you purchased it or the previous owner cleaned the board, leaving behind some residue such as packing material. I’d recommend returning it if you’re concerned. To proceed safely, you could run the board with the iGPU on the CPU (if available) and ensure there’s at least an HDMI or VGA port connected; otherwise, avoid powering it unless connectors are intact despite debris or damage.
Could the motherboard be the issue and might it affect your GPU? Remembering the 8-pin plug helps. You could return the motherboard if it’s defective, though GPUs are costly.
The same issue occurs with my Subaru, I just brush it off and continue driving, everything seems okay.
No way if it was a dodge—it should have been cooked before the smoke. Subaru smokes, rattles, knocks, oil comes out of nowhere, and the plugs are fouled after 250k miles. Still running down the road okay.
You found the smoked wire used for case fans. The bad ones are the cheapest parts in your setup. Swap out all similar components first.