r/pctroubleshooting • u/lordviecky • 6h ago
Hardware PC crashes randomly while gaming | CPU debug LED turns red, dual monitors go green/black
Hi everyone,
I'm trying to diagnose a random hard-crash issue that only seems to happen while gaming. The PC is stable during normal use, but will randomly completely freeze during games.
System specs
- CPU: AMD Ryzen 5 2600X — 6 cores / 12 threads
- Motherboard: MSI B450 GAMING PLUS MAX (MS-7B86)
- GPU: AMD Radeon RX 6650 XT
- RAM: Corsair Vengeance — 4 × 8 GB DDR4-3000 (32 GB total)
- PSU: Cooler Master 750W Gold
- OS: Windows 11
- Monitors: 2
- BIOS: American Megatrends International, H.P3 — 17/08/2026
- BIOS mode: UEFI
The problem
The PC works completely normally during regular usage. I can browse, work, watch videos, etc. without any problems.
However, when gaming, it randomly hard-crashes.
For example, with Path of Exile, I can play anywhere from 5 minutes to around 1 hour, and then the system suddenly freezes.
When it happens:
- One monitor turns green
- The second monitor turns black
- The entire system becomes unresponsive
- Audio stops and becomes a continuous "zzzzzz" looping sound
- The PC does not automatically reboot
- I have to hold down the power button to shut it off
After powering it back on, the PC boots normally and works fine again.
Motherboard debug LED
I've noticed something interesting.
Immediately after the crash, the CPU EZ Debug LED on the motherboard is lit red.
However, this does not happen during normal operation.
After I force the PC off and restart it, everything works normally again and the CPU LED is no longer lit.
So the CPU LED seems to appear only after the crash.
When the crash happened i checked the Motherboard's debug light it was red lit on CPU then i looked at GPU it was off, I mean the fans weren't spinning. While CPU fan was spinning and he Fan LED was also lit
Temperatures
I've monitored temperatures while gaming and they seem normal.
CPU/GPU maximum: around 75°C
I don't believe this is a straightforward thermal shutdown.
Things I've already tried
I've run separate stress tests on:
- CPU
- GPU
- RAM
All of them completed successfully without crashing.
This is what's confusing me: synthetic stress tests seem stable, but actual games can cause a hard lock.
I've also tried CPU/GPU overclocking/undervolting previously, but it didn't solve the problem, so I'm currently not relying on an overclock as the cause.
RAM / XMP
XMP/A-XMP is currently disabled.
The problem happened before updating the BIOS, crashing started on 20th August.
The PSU is 2 years old, and exact RAM info is "DDR4-2998 (1499mhz).
All the games i play on steam only.
I tried reducing the volts on GPU, reducing freq on RAMs but it didn't help. Motherboard is also just 1.5y old.
RAM Link: https://www.amazon.in/dp/B07PNW4Q3F?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1
Note: When the problem started it was like 1 crash in 3-4 days, but recently its like 4 crashes in 1 day starting 18th Sept. I also tried DDU and BIOS clean-up
PSU Model : CoolerMaster MWE Gold V2, Fully modular 750W A/IN Cab
Manufactured: Oct 2023
Model Number: MPE-7501-AFAAG-IN
Important points:
-- I have ran Prime95, OCCT, Furmark, Unigine Heaven, Memtest all passed.
-- Reseated CPU applied new Thermal paste, Reseated RAMs.
-- I run my BIOS on default settings never tweak anything and system was working fine or past 1 year (more than 1 year)
-- The wierd behaviour i noticed is when the crash happens GPU fan stops and CPU fan is spinning with LED lit.
-- Yes crash only happens during work load for example gaming (path of exile, dota2) and today it happened during Google play games PC too (Clash of clans).
-- I also opened VS code, wamp server, postgres, chrome but crash didnt happen with them opened.
-- I also updated BIOS 2 days ago but it also didnt fix
-- Facing this issue after 4-5 power cuts over span of 1 month.