Doesn't boot but the fan comes on at high speed

@brian34791 let's see what your motherboard looks like. We need to see what you are referring to as transistors. Post a picture of your motherboard etc. with your question. That way we can see what you see. 在已经存在的问题里加入图片

Alos, clarify this "unplug things". Let us know what kind off things you unplugged. Let us know which fan is on steroids. I assume you are referring to the CPU fan. That could be because of bad/failed sensors.

Next download the user guide for your computer from here and let us know what your computers form factor is.

Try to enter the BIOS. Unplug your computer. Remove one or even two RAM modules and/or disconnect the HDD. Then plug your computer in and try to turn it on. Restart the computer, press F2 while the Dell logo is on the screen. Let us know what happens.

is there any hope? H E double hockey stick, yes! Let's keep the vintage equipment going. It might take some work and some research but I am pretty optimistic with this.

While you work on your computer, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!