FAQ
TL;DR: Two PSUs were tested; "DO NOT forget to connect the 4‑pin / 8‑pin ATX +12V power plug. Otherwise, the system will not boot up." Use a quality PSU with proper 8‑pin CPU power rather than a 4‑to‑8 adapter. [Elektroda, badboy84, post #16770409]
Why it matters: This FAQ helps PC builders fix no‑boot issues when using 4‑pin CPU power on 8‑pin motherboards.
Quick Facts
- Asus H87M‑E can boot with 4‑pin or 8‑pin per manual quote, but PSU quality still matters. [Elektroda, badboy84, post #16770409]
- Low‑tier “White Energy 400W” was flagged; check against the “black list” and verify voltages. [Elektroda, kokapetyl, post #16770411]
- A 4‑to‑8 adapter spun fans, yet there was no display output afterward. [Elektroda, Plmkohehe, post #16771997]
- User retest with a second 4‑pin PSU showed the same no‑boot behavior. [Elektroda, Plmkohehe, post #16771785]
- One member reports the board only started after using a PSU with a native 8‑pin CPU plug. [Elektroda, 3029369, post #16771824]
Will a 4‑pin CPU power plug work in an 8‑pin socket on the Asus H87M‑E?
The manual quote says 4‑pin or 8‑pin can be used, but success depends on PSU quality and load. Weak PSUs may light LEDs while failing to start the board. "DO NOT forget to connect the 4‑pin / 8‑pin ATX +12V power plug." [Elektroda, badboy84, post #16770409]
Do I need a 4‑to‑8 pin adapter or a new PSU?
Prefer a reputable PSU with a native 8‑pin CPU connector. Adapters can power fans yet fail POST, causing no display. Forum guidance favored buying a good PSU over using an adapter for reliability and future upgrades. [Elektroda, badboy84, post #16770470]
Why do my fans spin but I get no display after using a 4‑to‑8 adapter?
Spinning fans only show that some rails power up. The CPU VRM may still be under‑supplied, so the system never POSTs. This exact symptom occurred after adding a 4‑to‑8 adapter: fans ran, but nothing appeared on screen. [Elektroda, Plmkohehe, post #16771997]
I tested two different 4‑pin PSUs and it still won’t boot—what next?
Two PSUs with 4‑pin CPU power yielded the same result in the thread. Move to a PSU with a native 8‑pin CPU plug. If it still fails, proceed with CMOS reset, RAM reseat, and buzzer diagnostics. [Elektroda, Plmkohehe, post #16771785]
How do I clear CMOS and attempt first‑boot recovery on H87M‑E?
- Power off, unplug PSU, then short the CLR_CMOS jumper per board silkscreen for a few seconds.
- Install one known‑good RAM stick in the primary slot; reseat if needed.
- Connect a buzzer and attempt boot; listen for RAM‑related beep codes with RAM removed.
"It is worth trying to do a BIOS reset (jumper on the board)." [Elektroda, dt1, post #16772099]
Is my motherboard dead if it shows a green LED but won’t start?
Not necessarily. A poor‑quality PSU can light standby LEDs while failing under load. Verify PSU voltages with a tester or multimeter, then try a quality unit. Only suspect the board after these checks and a CMOS reset. [Elektroda, kokapetyl, post #16770411]
What is the EPS12V 8‑pin CPU power connector?
It’s the dedicated 12V power feed for the CPU VRM. Some boards accept 4‑pin, others need all 8 pins to start reliably. One user’s board did not start until an 8‑pin‑equipped PSU was used. [Elektroda, 3029369, post #16771824]
Can integrated graphics vs. a discrete GPU change this outcome?
Mention intended graphics when selecting a PSU. A discrete GPU raises total load and increases the need for a stronger, reputable PSU. Forum advice recommended stating whether you’ll use iGPU or add a GPU before buying. [Elektroda, badboy84, post #16770470]
Is a 4‑to‑8 adapter safe to use long‑term?
It may work, but it won’t deliver the full current that an 8‑pin rail can supply. The thread warns this solution does not provide the right amount of power, risking instability under load. [Elektroda, 3029369, post #16771859]
My fans run but there’s no video—what quick checks should I do?
Reset CMOS, boot with one RAM stick, and try both iGPU and GPU outputs. Connect a buzzer; remove RAM and check for beep codes. If silent, focus on PSU and CPU power cabling. This sequence isolated similar no‑display symptoms. [Elektroda, dt1, post #16772099]
Should I measure PSU voltages before replacing parts?
Yes. Measure 12V, 5V, and 3.3V with a tester or multimeter before buying anything. The forum urged voltage checks and referenced the PSU “black list,” highlighting quality concerns. "Measure the voltages of the power supply." [Elektroda, kokapetyl, post #16770411]
Could the motherboard require all 8 pins even with a low‑TDP CPU like Pentium G3258?
It can. One user’s MSI board with 8‑pin CPU power showed no life on 4‑pin, yet started with a PSU that had 8‑pin. Board design, not CPU TDP alone, dictates the requirement. [Elektroda, 3029369, post #16771824]
What’s the role of the motherboard buzzer/beeper in diagnosis?
The buzzer emits beep codes that indicate missing RAM or other faults. If it beeps with RAM removed, the CPU and some logic run, so power delivery may be okay. Lack of beeps narrows the fault. [Elektroda, dt1, post #16772099]
Could a bad PSU make the system look totally dead even though LEDs are on?
Yes. A weak unit can bring up the standby LED but fail to start fans or CPU VRM under load. The thread flags the low‑tier PSU and advises quality testing or replacement. [Elektroda, kokapetyl, post #16770411]
What should I include when asking for a PSU recommendation?
State budget, planned GPU or iGPU use, and desired reliability. The thread suggests opening a “What to buy” topic with your amount and graphics plan for targeted advice. [Elektroda, badboy84, post #16770470]
Edge case: Everything powers, but still no POST after new PSU—now what?
Reset BIOS, reseat CPU and RAM, test one DIMM, and use the buzzer for codes. If it still fails, the board may be damaged, as one helper concluded after multi‑PSU tests. [Elektroda, dt1, post #16772099]
