Dell Precision 7510 TB16 Boot Issues

So I got the TB16 to use with my Windows 10 Precision 7510. I've had issues with the USB devices dropping out randomly but I seem to have got that under control (for now).

It might be if the devices are intermittent, they would exhibit problems during a Pre Boot Scan.

I wanted to boot from a USB DVD drive that was connected to the TB16. But when I tried to boot the laptop got stuck on the Dell logo and wouldn't go into POST.

You are wanting to boot a UEFI capable DVD, such as the Win 10 Install media, connected to the TB16?  If that is the case, I can test to see if I can do it.  I am wondering if the Thunderbolt is connected to the PCIe bus if any device there will be checked for boot compatibility.  

I suppose you can boot from that USB DVD when connected directly to your system?

Yes that is exactly what I am trying to do. It wasn't WIndows 10 install media, rather a boot CD for a backup and recovery software but I imagine the Win 10 DVD would have the same result. I haven't actually tried testing whether the system boots with the TB16 connected but no USB devices connected to the TB16. Might give that a go later. Yes when the DVD drive is connected directly to my system or connected to a USB hub that is connected to my system that works fine.

I'm still having the problem with the USB ports on the TB16 being intermittent though. I've got around it in the sense that when it disconnects it automatically reconnected a few seconds later as opposed to remaining disconnected. But it is still dropping out randomly and quite frequently. I haven't tried the USB C port or the ethernet port at the back of the TB16 but going by some of the previous complaints about the TB16 they would display the same issue. Any idea how to fix this issue as well?

I was able to boot my 9365 from the DVD drive attached to the USB port on the TB 16.  I set the Bios for the first Thunderbolt boot option only, not the pre-boot modules.

After selecting the DVD from the F12 menu, the text to hit a key to boot from the DVD was very small on this machine.

I did have a mouse and Ethernet connected to the TB 16.

I don't know the configuration of your system but there usually seems to be only one USB C port usable for Thunderbolt operation.

My USB ports appear normal and will chime when the dock is plugged and unplugged.

I've tested it with Thunderbolt Boot only now and that worked fine so the problem is with the Thunderbolt Pre Boot Modules. Any idea why that is happening?

My USB ports on the dock chime as expected as well. They just disconnect then reconnect randomly. The chime gives away it's happened along with the message saying what to do with my DVD drive and external hard drive. Any idea how to fix that? Is it a hardware issue maybe?

Well I am having a different issue now. I updated the BIOS to the one that was released a few days ago (I was using the previously released one before) and now the USB devices on the thunderbolt dock won't show up in This PC now. When I connect a device to a USB port on the dock I hear the beep indicating that it has been recognised but the device won't show up on This PC. USB flash drive didn't show up in disk management either. Any idea what is happening now? Beginning to think this dock may be more trouble than it is worth.

Have you checked the TB firmware and driver for updates.  The ASmedia USB drivers are loaded and you are plugging the USB device to one of the USB 3.0 ports.

I can only say how my system behaves with the dock.  But if you are hearing chimes, the computer is seeing the connection.  If those same USB devices work when connected directly to your system, they should work on the dock.  If not, maybe the dock is defective..

The fact your system needs the external power even with the dock connected might cause our systems to react differently.  Say, if the 5 volt power was not steady, it might cause USB devices to disconnect.  But I really don't know the answer.  Trying different types of USB devices to troubleshoot is all I can suggest.  

Yeah all drivers are up to date. I installed them manually in the order based on what Dell recommended. I might try testing this on a fresh install just to see if that makes any difference. Will probably need to contact Dell about a replacement if that doesn't figure things out.

Well I've done a bit more testing and have narrowed things down a bit more. Booting from the USB DVD works fine as long as "thunderbolt adapter pre boot modules" is disabled. If I enable that I end up with the same problem of not getting to POST. DVD is booting fine now so that's not really a concern for me.

The USB issues though are still there. I tried it on a fresh install twice and both time I ended up with the same result. When I manually install the drivers, restart then plug in dock as per the instructions the dock works fine without losing connection. I kept it on for a few days, disconnecting and reconnecting devices with no problems. The moment I restarted my computer again the dock started malfunctioning. After a short while all the USB devices dropped out and wouldn't reconnect again unless I restarted computer or disconnected and reconnected the dock to the laptop. The problems are fixed again if I reinstall all the drivers but then they resurface once I restart the laptop. Now constantly reinstalling the drivers is not a practical solution but it appears that it might be either a drivers or power management issue. I've tried going into device manager and unchecking "allow the computer to turn off the device to save power" but that hasn't helped. Any idea what else I could do to try and fix this?

I can't really think of anything else since I can't test your exact system.  But noticing if the chimes work when you connect and disconnect the system from the dock, should be a clue as to where the configuration is having problems.

When connected to the dock you should see the ASMedia device in Device Manager.  If you look at the properties there is a Events tab which may list what is happening.  Be aware the window is small but has a scroll bar.  If you select one entry it will show a description of that event.

The events tab is practically empty and only shows when drivers were installed/uninstalled. The chimes work fine when connecting and disconnecting the dock from the laptop. They also work fine when connecting/disconnecting devices from the dock. When they don't work though is when the USB devices have dropped out and don't reconnect instantly. There are no chimes when  disconnecting/connecting USB devices from the dock. The chimes all come back and work as expected when the dock is disconnected and reconnected back to the laptop, until the USB devices drop out again that is. I'm going to try and get a replacement dock and see if that helps. But it seems like its more software related.