Hi all,
Ive got a reoccurring issue that has been effecting a couple of dedicated machines that operate remotely. Users are reporting that their systems are unable to turn on. Walking them through the troubleshooting, there is no issues with the monitor. Power is being applied, the system lights turn on. We can confirm the network activity lights on the LAN port and the router has negotiated a link speed. But if we log into the router, we see no packets coming from the PC.
Now, the weird part. When the computer is shipped back, it magically starts working again. Ive tried running a memtest to see if maybe its bad ram, but it always comes back passed. I believe the issue is due to a multiport pci serial card. Sometimes if the cable is removed that connects to that pci, the system will boot. Other times, it completely kills the pc. Until of course it gets shipped back, then it will work again.
Ive really hit a dead end with this issue. Im not sure how to diagnose a no post situation without physically being there. At the very least, I wish I could replicate the issue in person. Unfortunately, the issue is occurring with multiple computers and pci cards. Doubtful its a one off bad piece of hardware.
If anyone has any experience troubleshooting a no post situation remotely or has had issues with pci cards, I’d really appreciate it!
Should have been more clear about the remote part. The systems operate remotely from me, I can access them via the internet. The users need to use the screen to operate it. This is just a windows 11 computer after all.
As for the router information, thats part of the reason I know there is power to the entire thing. I can access the router page and see that the link speed was negotiated correctly, at 1gb per second. If they unplug the ethernet, the port reads disconnected.
But 0 packets are getting sent from the computer. I believe those are ARP, but the router page doesnt define it. Just has a table with packets in and packets out. Packets going in will usually have a couple from the router. Always 0 with packets coming out. Theres actually a ping function built into the router, and that doesnt respond at all.
BIOS is not setup during boot to use any sort of networking. No PXE boot or anything like that. On this particular motherboard, you have to enable the network stack, so I dont think its that. System is setup to always turn on when power is applied to bring all the other components online together.
Anyway, thanks for taking time out of your day to respond!
Ah, okay. So then they aren’t getting any video display from the BIOS when the problem comes up. Okay, yeah, then that’s pretty convincing that it’s early in the boot process. So, yeah, OS probably isn’t a factor.
Okay. So, strictly-speaking, “frames” are what one calls things at the Ethernet level, and “packets” at the IP level, so if one assumes that the router page is actually being technically-correct, it’s possible that the computer is still doing things at the Ethernet level. But, yeah, gotcha.
considers
Well, let’s see. This is kinda more at the brainstorming level. You said that you stuck the thing in a fridge, so I’m assuming that the user is at a colder-than-normal situation, not warmer. I guess you’ve got:
Temperature. You said that you tried that. If it’s colder than normal specifically around the time that the problem shows up, you might also consider humidity – if it’s high humidity, then condensation inside electrical devices can be a problem. Like, especially if this thing is outside and you’re getting (electrically-conductive) dew forming on surfaces in the morning or something like that, that can wreak havoc on electrical devices. I don’t know what the best way to diagnose that would be. A hygrometer will tell you the relative humidity. If it’s in the open, maybe leave a small space heater aimed at the system, which should produce lower-humidity air where the air is warmer than the surrounding air, and see if the issue goes away. If it’s in an enclosed space, maybe run a dehumidifier.
You’ve got the possibility of problems coming in from your external electrical lines — you have at least serial, power, and networking going into that machine. You might try, for troubleshooting purposes, if it arises again, having the user pull all of the lines connected to external stuff other than power, including the Ethernet cable and that serial thing, and seeing if it becomes impossible to reproduce then.
You said that some motor was involved. If you’re talking some kind of industrial setup with other machinery around, I guess something could theoretically be emitting some kind of strong electrical field that creates problems. I’ve never heard of a situation where a PC won’t work because of that, but I’d imagine that it’s possible.
I once recall hearing about a situation at a company I was working at where our support people had problems with vibration in a customer’s environment affecting the device — they couldn’t reproduce the problem back at the company. That took them some time to work out.
Some of that’s pretty exotic, but if you’re just looking for potential leads to consider, that’s all that immediately comes to mind.
Oh wow this is a fantastic write up! I really appreciate the effort you put into this. You’ve certainly given me lots to ponder over. I wonder if there is some credence to the humidity issue. Id have to do some digging on when the issue occured and what the conditions were like but some of the locations do get humid.