Dell Thin Client Hidden Self-Test Program

Overview

While setting up Linux on a Dell Wyse thin client with a 2.4GHz quad-core CPU, I accidentally discovered the built-in EPSA (Pre-Boot System Assessment) diagnostics tool. Press F12 during startup (with Secure Boot enabled) to run comprehensive tests on CPU, memory, video, and more. It even shows temperature sensors and fan speeds (all 0 RPM since this is fanless). This is a feature Dell has included in laptops and PCs for years, but I’d never seen it this detailed on a thin client.

Key Moments

• Pressing F12 during boot with Secure Boot enabled
• EPSA Pre-Boot System Assessment launches
• Running CPU stress tests
• Running memory tests (takes 10-15 minutes)
• Temperature monitoring: CPU and motherboard sensors, memory temps
• System configuration details: 240GB SSD, AMD GX-424 quad-core APU with Radeon GPU
• Two 4GB RAM modules (not matched, but works—supports up to 16GB)
• Test results tabs: Cables, Hard Drive, OS Boot Path, USB Hubs, Video Card
• Event log from BIOS

Full Transcript (Edited)

Hey there YouTube, so today I’m working on this little Dell thin client that I have here. It’s a Wyse thin client with a 2.4 gigahertz quad-core CPU. This video is just going to be about a little feature that I just found out.

In order to set up Linux on this, I had to change it to use Secure Boot. Let me show you what I accidentally found out when pressing some keys during startup. Yep! As you can see here, this has a built-in stress test tool. If you press F12 as it’s starting up with Secure Boot on, it runs this nifty little stress tester. It’s called the EPSA Pre-Boot System Assessment, and it runs through a bunch of diagnostics.

Dell laptops and some PCs have had this for a long time, but I’ve never seen it quite as elaborate as this one. Right now it’s running through some CPU tests and memory tests. The CPU took a while, and now it’s running through memory. I also like how it’s telling me the temperatures for the memory modules and the CPUs. Up here, this system has no fan, so all the fans are at zero RPM.

I’m just waiting right now for the memory tests to finish. Once that is done, I’m going to show you what’s underneath all these tabs because I’m literally doing this in real time—I haven’t seen this before.

[Tests complete]

Okay, so this took a long time, probably about 10-15 minutes for the first series of tests. Now it is asking me if I want to go ahead and continue and spend 30 more minutes doing some additional memory tests, but I’m not going to do that. I’m going to say no to this and let’s take a look through here.

As you can see here, it ran through cables, hard drive, OS, video card, CPU, system management, and memory. I kind of like how they have the little icons here—that’s kind of cute. Over here, like I mentioned before, you can see now it has CPU temperature sensors, probably some motherboard sensors throughout the motherboard, and then the memory. It’s funny—the memory is the hottest part, I guess, because it doesn’t have much dissipation there.

Configuration: as you can see here, I have a 240 gig SSD installed. It tells you a little bit more about the items that are plugged in. It’s got an AMD GX-424 system-on-chip with a Radeon GPU built in, and that’s a quad-core AMD APU. This computer has two memory slots, and I have four gigs on each slot. As you can see here, they’re not matched correctly, but it works. I believe you can put 16 gigs in this unit.

I found this pretty cool. If you have one of these thin clients, try putting it in Secure Boot mode and press F12 several times as you power it on, and it should pop this up if it’s a modern unit.

Hopefully that was interesting. If you like this kind of stuff, please subscribe and leave me a comment below. Let me know what you think. If you know anything else about this little computer, let me know. Yeah, until next time!