Check if the HP Z420 FMB 1101 has a corrupted BIOS or is damaged.
Check if the HP Z420 FMB 1101 has a corrupted BIOS or is damaged.
MoBo: FMB 1101 LGA 2101 CPU paired with Xeon E-5 1620 PSU, Thermaltake TR600W (UK variant noted). GPU is VisionTek ATI Radeon HD 4670, 1GB RAM. Patriot memory module, 4GB storage. Images attached for context, though not my own. (Search results for fun.)
SHORT SUMMARY: No video appears on the screen despite a working motherboard. CPU and GPU lights are solid, fan spins, but nothing displays. The graphics card is outdated and causes visual glitches. I’ve performed a complete rebuild. I see red blips for CPU and RAM, yet the board remains silent. The GPU runs intermittently, showing some activity. I’ve tried different PSUs, updated components, and even swapped parts, but still no output. The situation feels frustrating and confusing.
LONG DETAILS: Brother began assembling his system a few months ago. He reviewed a tutorial video, purchased components without prior knowledge, and faced a power failure warning. After replacing the motherboard with a new one, I noticed persistent red blinks for CPU and RAM, but nothing on the screen. The GPU still spins but doesn’t render anything. I attempted a BIOS recovery process using an SDH guide, which resolved the issue—LEDs stopped signaling faults when everything was connected properly. However, once the system restarted, no video appeared again. I’ve tested with another motherboard and CPU, yet the problem persists. I’m trying to figure out whether the motherboard itself is faulty or if something else is preventing proper hardware recognition.
Welcome to the discussion boards! I have a HP z620 nearby and some experience with these stubborn old machines and their error codes, so I’m hoping I can assist. First, have you considered posting on HP forums? Employees there might be able to offer more targeted support. Second, have you tried rearranging the memory slots? It seems like the problem could be related to the CPU or power supply delivery. You mentioned it would shut down during heavy CPU usage, which suggests it might be drawing excessive power and the PSU couldn’t cope. My 620’s circuit board (though mine is a bit unusual) uses original PSU connectors and needs the exact model, while yours likely doesn’t. The large riser connector under the CPU socket stands out on my board, whereas yours lacks it. Also, look closely at the power area above the CPU—any signs of burning or damage could point to the same issue. Have you tried changing the SATA ports used for booting? That’s probably not the main cause, but it’s something I’ve encountered before—especially with SAS drives on AHCI. You might also want to try adding more RAM; why are you limiting yourself to just 4GB? The z620 performs poorly in single-channel mode, and it could be an ECC issue or a memory problem. My take is either a CPU fault or a power supply concern. Any alternative CPUs or PSUs you’re considering? I really wish I could help further.
I just skimmed a part I didn’t catch. Did you switch it from 115 to 230 while the PSU was plugged in? Or while the PC was running? Yeah, that would be tough—like trying to adjust wheels on a moving bike at 10 ft/s. It sounds like the first board might have had issues, possibly due to firmware, and the second one likely failed from a power surge caused by the PSU voltage. I’d recommend getting a Dell Precision from eBay with all the necessary components and using the original PSU, CPU, and RAM. Skip the GPU; a Quadro K620 works well as a budget GPU alternative if you want something cheap.
Thanks for the introduction! The device was turned off even though it was connected, and the CPU didn’t appear to be under heavy use just to start the installation process. It took a while before things stopped working properly. I should note that I’m using a 24pin-to-18pin adapter; the Mobo is 18pin and didn’t cause any problems. I’ll need to disassemble my main board to install the 850W Corsair and test it before giving back the MOBO. I’ve tried RAM in various slots, but the best way to check is with a single stick. I’m pretty sure the issue was hardware-related on the original board before I started tweaking the BIOS. It’s too late to worry about that now. I think the problem is either hardware or software, and it seems hardware is more likely. Hardware is new, software is old. Updated October 6, 2021 by SilentTyrant76
I've revisited this project several times and still can't shake it off. The BIOS doesn't detect any RAM, CPU, or power issues, yet it doesn't trigger a beep code when the GPU isn't installed. I've gone through almost every online search related to this problem and haven't found a clear solution.