Nvidia Tesla S2050 + Tesla K20 - problems.

Good day. I purchased Nvidia Tesla S2050 Server without Tesla M2050 cards and installed Tesla K20 cards in it and I had problems. At first, the S2050 turned on for 10 seconds when the main Dell server that I use was turned on, then it turned off. But I found a button on the board and pressed it. Now the S2050 is turned on, the cards are visible to the nvidia-smi, but the fans of the S2050, as before, turn on only at the start for 5-10 seconds, only the power supply coolers work. How to make the fans work S2050? Cables and Nvidia P797 cards are OK.

±-----------------------------------------------------+
| NVIDIA-SMI 340.107 Driver Version: 340.107 |
|-------------------------------±---------------------±---------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 Tesla K20Xm Off | 0000:0B:00.0 Off | 0 |
| N/A 55C P0 59W / 235W | 12MiB / 5759MiB | 0% Default |
±------------------------------±---------------------±---------------------+
| 1 Tesla K20Xm Off | 0000:0C:00.0 Off | 0 |
| N/A 51C P0 61W / 235W | 12MiB / 5759MiB | 0% Default |
±------------------------------±---------------------±---------------------+
| N/A 54C P0 60W / 235W | 12MiB / 5759MiB | 0% Default |
±------------------------------±---------------------±---------------------+
| 3 Tesla K20m Off | 0000:15:00.0 Off | 0 |
| N/A 49C P0 50W / 225W | 11MiB / 4799MiB | 0% Default |
±------------------------------±---------------------±---------------------+
±----------------------------------------------------------------------------+
| Compute processes: GPU Memory |
| GPU PID Process name Usage |
|=============================================================================|
| No running compute processes found |
±----------------------------------------------------------------------------+

He could make boxing coolers and slots PCI-E 16x 2.0 work. It turned out in order to make the coolers work enough to pull out of the slot or cut and isolate the two blue wires that go to the front panel board to which the coolers are connected that are blowing the video cards.
In order for the 16x slots to work, it is necessary on the board which is located across the box to press and lock the button, or completely solder it and solder 2 wires to its place by closing the contacts. After that, expansion slots start working.
I hope it will be useful to other people besides me.