Update on the problem. I blasted some canned air everywhere. Not much dust. Still wont start and fans are blasting!  I was trying to boot up, unplugging and plugging cord back to power supply, when I felt a reset button on the power supply. I discovered while plugged in and reset button pressed, the fans would race. Upon releasing the button the fans stopped. I believe either the button was stuck due to dust or possibly was being depressed by something (a cable or wire). Long story short. The issue is resloved!
I have a Precision T3610 work station, running Windows 10 Pro, 64 bit. Samsung 860 Pro SSD system drive (512GB) and separate SATA 1TB data drive. It's a little more that six years old. Fans are running full speed, power light is solid white, and code is 3. I was able to start up briefly after plugging it in and pressing the power button. I ran some diagnostics from the Dell support assist website. No errors were found. After a while, I shut down using the normal method, then the fans came on full blast. the only way to stop it was to unplug it. Note: Every time I try to start it, I plug in the power cord, the machine cycles briefly, Light is steady white, codes read 3 4, on fan kicks on at full speed, then code changes to 3 only with steady white power button. Then holding the power button, the light goes off, then a second fan comes on at full speed also. All during this, the computer will not boot up. Any solutions?
Precision T3610 fans on full speed, will not turn on.