Question PC Instability Escalating: Cold Boot Delays, Boot Failures, USB Glitches - PSU or Motherboard?

[jyotish4855]

Hello everyone,

I'm dealing with a complex and evolving set of issues with my custom-built PC and I'm hoping to get some community insight. The PC works perfectly at a local repair shop, but is very unstable at my home.

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**PC Specifications:**
* **CPU:** Intel Core i3-4th Gen
* **Motherboard:** "Consistent" H81 (a modern, budget reproduction of an old chipset)
* **RAM:** 8GB DDR3 Samsung (single stick)
* **SSD:** 256GB "Consistent" SATA SSD
* **PSU:** Ant eSports Value eCo 400 (This is the 3rd PSU in about a year)
* **UPS:** Zebronics U735 with AVR
* **OS:** Debian (fresh install)

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**Timeline of Symptoms:**

1. **Initial Problem (Months Ago):** After a period of very heavy use (running local LLMs), the PC started freezing randomly. At the time, it had a Zebronics 450W PSU.

2. **"Fix" Attempted:** I replaced the Zebronics PSU with the current Ant eSports 400W PSU and did a fresh install of Debian. This solved the random freezing.

3. **New Problem Emerged:** After the PSU swap, a new, very consistent issue started: a 20-30 second boot delay.
* This ONLY happens on the first boot of the day (a "cold boot").
* During the delay, the screen is black (no motherboard logo) and the case power light blinks. After 20-30s, it boots normally.
* All subsequent reboots throughout the day are fast and normal.

4. **Recent Escalation (Last Few Days):** The problems have gotten much worse.
* The PC sometimes fails to boot entirely. The power light will turn on, but nothing happens on screen.
* My mouse has started acting weirdly: single clicks often register as double clicks.

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**Key Observations & Diagnostics Steps Taken:**

* **The "Repair Shop" Clue:** The PC tower, by itself, works 100% perfectly at a local repair shop, pointing to an environmental issue at my home (likely power quality).
* **Power Filtering:** I have an AVR UPS, but the issues persist and have gotten worse.
* **PSU History:** The PC has a history of PSU failures. Both the current and previous PSUs are very low-budget, non-certified models.
* **BIOS Settings:** The motherboard has a 2022 AMI BIOS. Enabling "Fast Boot" had zero effect on the cold boot delay.
* **Hardware Checks:** RAM has been removed and reseated firmly. The CMOS battery is holding the system time correctly.

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**My Current Theory:**

The root cause is poor power quality at my home. The budget UPS isn't enough to clean it up. The current Ant eSports PSU is not only failing to handle this "dirty" power, but is now actively failing, leading to the escalating symptoms like total boot failures and the USB mouse glitch. The initial cold boot delay is likely the budget motherboard's sensitive BIOS reacting to the unstable power on startup.

Based on this, I have stopped using the computer to avoid damaging other components.

**My Question for You:**

My plan is to purchase a quality, 80+ Bronze certified PSU (like a Cooler Master MWE Bronze V2) and not use the PC until it's installed.

Do you agree that the escalating, power-related symptoms (boot failures, USB glitches) make the PSU the primary and most critical suspect? Or is it more likely that the budget motherboard is the true culprit, despite the evidence pointing to power delivery issues?

 

[Lutfij]

Welcome to the forums, newcomer!

The PC works perfectly at a local repair shop, but is very unstable at my home.
The only thing that's different from the repair shop and your home is the source of power from the wall outlet. You seemingly have a grounding or worse, a power related issue. You should call in a certified electrician and ask them to scope out the wiring in your abode or to your room that the PC resides in, at the very least.

* **PSU:** Ant eSports Value eCo 400 (This is the 3rd PSU in about a year)
+
At the time, it had a Zebronics 450W PSU.
A slew of horribly built PSU's IMHO.

My plan is to purchase a quality, 80+ Bronze certified PSU (like a Cooler Master MWE Bronze V2) and not use the PC until it's installed.
If you don't want to buy an entirely new PC with brand new parts, then you should look into a reliably built 450W~550W unit and call it a day. If you come across PSU tier lists, try and pick up an unit that's as close to Tier - A as possible.

Speaking of purchasing, where are you located? What is your budget? If you're not located in the USA like the majority of our forum visitors, you should include sites you have access to, it also helps us understand what brands and parts you don't have access to and at what price.

Moved thread from Components section to Systems section.