# Unusual behavior of P2ADDH462-KVM-SWITCH HID ports and front PC light **URL:** \ **Category:** Racks, Shelves, KVMs\ **Tags:** usb\ **Created:** [February 4, 2026, 6:30pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881 "2026-02-04T18:30:53Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![gmarler](https://avatars.discourse-cdn.com/v4/letter/g/f14d63/32.png) [@gmarler](https://community.startech.com/u/gmarler)\ **Post date:** [February 4, 2026, 6:30pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881/1 "2026-02-04T18:30:53Z")
After setup of this KVM to a Mac (PC 1) and a Linux machine (PC 2), noticing a couple of unexpected behaviors: - I’ve got a USB-C to USB-B cable from both computers to their respective PC USB-B Host connection - The Console HID USB ports don’t work with my wired USB keyboard at all - have to plug it into one of the Console 5Gbps Hub Ports instead to get the keyboard to work with either PC - When I select The PC 1 (MacBook) button on the front both the PC (green) and Hub (red) lights come on solid and stay that way - but when I select the PC 2 (Linux) button on the front, only the Hub (red) button comes on solid, but the PC (green) button continuously blinks. Is this an indication of a problem I should fix? What does it mean? ---
**Author:** ![DavidF](https://yyz2.discourse-cdn.com/flex012/user_avatar/community.startech.com/davidf/32/23_2.png) [@DavidF](https://community.startech.com/u/DavidF)\ **Post date:** [February 6, 2026, 4:34pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881/2 "2026-02-06T16:34:33Z")
Hello @gmarler , Thank you for taking the time to ask your question here on the [StarTech.com](http://StarTech.com) community page. I am sorry to hear about these issues on the P2ADDH462-KVM-SWITCH. We will take some time to review each of your points and consider troubleshooting options. - Thank you for confirming the USB connectivity between each computer and the KVM. - We expect standard USB keyboards to work well with our KVMs. If the keyboard is not standard; a gaming keyboard, has USB ports, has other features, we suggest the workaround that you have found. - Thank you for confirming the USB function on PC 1 (the Mac). - The LED blinking probably indicates that the host connection is not fully detected. This behavior is described in the P2ADDH462-KVM-SWITCH manual and technical specifications. Please let us know if this helps you isolate what is happening with this KVM. We can do our best to help you further if these symptoms persist. Sincerely, @DavidF ---
**Author:** ![gmarler](https://avatars.discourse-cdn.com/v4/letter/g/f14d63/32.png) [@gmarler](https://community.startech.com/u/gmarler)\ **Post date:** [February 8, 2026, 5:10pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881/3 "2026-02-08T17:10:16Z")
My keyboard is a WASD CODE Model V2B - not a Gaming keyboard, and has no other ports or a USB hub - just a plain USB keyboard. I swapped all the ports/cables/PC 1&2 connections, and the blinking green light problem follows the Linux machine where ever it goes. I even tried swapping the USB-C to USB-B cable with a USB-A to USB-B cable from the Linux machine along the way - no difference. ---
**Author:** ![DavidF](https://yyz2.discourse-cdn.com/flex012/user_avatar/community.startech.com/davidf/32/23_2.png) [@DavidF](https://community.startech.com/u/DavidF)\ **Post date:** [February 9, 2026, 4:09pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881/4 "2026-02-09T16:09:03Z")
Hello @gmarler, Thank you for replying with your keyboard model and the results of the swap tests. The specifications found online for the WASD Code Model V2B show that it has some special features, but it should work as a standard HID device. This keyboard has dip switches and QMK firmware, perhaps these expose some functions that do interact predictably with a hardware based KVM like the P2ADDH462-KVM-SWITCH. Consider checking WASD CODE support to confirm. Perhaps there is a configuration that may help it better accommodate the hardware based KVM? As a basic check for the HID ports on the P2ADDH462-KVM-SWITCH, try testing with an OEM or other standard keyboard just to be sure the ports themselves work. Regarding the USB flashing indicator: since you have isolated it to the Linux system let’s focus there. The front panel LEDs on these KVMs should be rather simple. The flashing LED could indicate that the KVM is not quite detecting powered USB connections from the Linux machine for some reason. We can dig a bit deeper with you. Can you share more about that computer? For example: - What is the make and model of the system? - Could these ports be lower power ports? - Are there any hubs or docks used between the KVM and the Linux machine? - Do you see any errors regarding USB connections in your distribution’s logs? (dmesg) Please let me know if this helps you answer your questions, or if you would like to work with our support team directly. Sincerely, David F. ---
**Author:** ![gmarler](https://avatars.discourse-cdn.com/v4/letter/g/f14d63/32.png) [@gmarler](https://community.startech.com/u/gmarler)\ **Post date:** [February 9, 2026, 5:24pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881/5 "2026-02-09T17:24:55Z")
WASD is no more, sadly. But, the DIP switch settings are set to be a completely HID device (no extra functionality enabled, like rollover keys, etc) - works on all other HID type ports. As to the Linux computer: - The make is an MSI Mag B650 Tomahawk Wifi motherboard, and I’ve tried the following connections: - Connected the USB-C to USB-B port to the USB-C port on [\* this](https://www.amazon.com/GRAUGEAR-microSD-Internal-Connector-Required/dp/B0DHGVNDPZ/ref=pd_rhf_dp_s_ci_mcx_mr__d_sccl_1_1/141-7506328-6544323) front port assembly, which is connected to the JUSB1 jumper on the motherboard, which is a USB 3.2 Gen 2 Type-C Connector. This should have PLENTY of power. - Connected the USB-A to USB-B cable to a case provided USB port that connects to the JUSB3 USB 2.0 header. - In all cases, no errors regarding USB connections in dmesg - I’ll try connecting the keyboard to the HID port again, just to see if there’s an error, nor simply no message at all when I plug it in. Oh, and the HID ports don’t work for _either_ the Mac or the Linux systems connected. ---
**Author:** ![DavidF](https://yyz2.discourse-cdn.com/flex012/user_avatar/community.startech.com/davidf/32/23_2.png) [@DavidF](https://community.startech.com/u/DavidF)\ **Post date:** [February 10, 2026, 3:52pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881/6 "2026-02-10T15:52:55Z")
Hello @gmarler, Thank you again for sharing more about the keyboard and LED troubles. I am sorry to hear that it may be hard to gather more support data about the WASD keyboard. I would certainly expect a standard USB HID keyboard to work fine on the P2ADDH462-KVM-SWITCH. Testing with another keyboard could be worthwhile sanity check, and might help us isolate an issue with the KVM port too. This may be a good time to consider trying the KVM reset / Power cycle steps that I have added to this forum earlier. - [KVM Reset / Power Cycle](https://community.startech.com/t/monitors-keep-disconnecting/1145/2) This modified power cycle has helped me resolve USB connectivity many times in the past. Regarding the power for the USB port. I suspect USB 2.0 power would be more than enough power for the KVM to recognize the port correctly. Between the two connections tried on the MSI system I suspect the USB A connection from the computer case port to the KVM may be more reliable for testing. I am curious if the steps linked here help, or if you find any clues in the logs after your test. If the issues persist for you after these steps we may have to consider the KVM further. I can reach out to you directly by email too. Sincerely, @DavidF ---
**Author:** ![gmarler](https://avatars.discourse-cdn.com/v4/letter/g/f14d63/32.png) [@gmarler](https://community.startech.com/u/gmarler)\ **Post date:** [February 10, 2026, 11:11pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881/7 "2026-02-10T23:11:19Z")
Going through the KVM Reset / Power Cycle procedure, I stumbled upon the problem: - If you plug the keyboard into the **bottom** HID port, the backlighting comes on, but the keyboard doesn’t work (i.e., doesn’t respond to keystrokes) for either PC 1 or 2 - If you plug the keyboard in the the **top** HID port, both the backlighting comes on and the keyboard works for both PC 1 and 2, **AND** the green light stops flashing for PC 2 (the Linux box). - Using the USB-A to USB-B or the USB-C to USB-B don’t make a difference. Everything works great as long as you only plug the keyboard into the top HID port. So either the bottom HID port on the KVM has a problem, or the HID ports differ somehow. ---
**Author:** ![DavidF](https://yyz2.discourse-cdn.com/flex012/user_avatar/community.startech.com/davidf/32/23_2.png) [@DavidF](https://community.startech.com/u/DavidF)\ **Post date:** [February 11, 2026, 3:27pm UTC](https://community.startech.com/t/unusual-behavior-of-p2addh462-kvm-switch-hid-ports-and-front-pc-light/1881/8 "2026-02-11T15:27:50Z")
Hello @gmarler, Thank you for trying that reset procedure. I am glad to hear that it gave you enough clues to help diagnose the HID port issues. We can certainly help some more with the bottom HID USB port. You may want to try another simple USB device on that port, like a standard wired USB mouse any other simple USB device. If that bottom USB device still doesn’t work with a different device, try those reset steps once more. Let me know how that test goes and if the port is still not behaving for you I will connect you directly with our support team for the next steps. Keep me posted and we will do our best to get this resolved for you. Sincerely, @DavidF