Device not turning on

[Amiamusic]

I have an hp prodesk 600 g6 mini pc

and it won’t turn back on, i turned on , stayed that way for 25-30 mins and shut down , when power knob is pressed it light up but when released nothing turns on, I also have a yellow blinking light under the low power option board connector 

idk what to do 

[Raqeeb26]

Hi @Amiamusic ,

Welcome to The HP Support Community.

Thank you for posting your query, I will be glad to help you.

I'm sorry you're dealing with this frustrating issue. The set of symptoms you're describing—working for a bit, shutting down, the power light only illuminating when held, and a blinking yellow internal light—points very strongly to a hardware failure detected by the PC's self-test.

That blinking yellow light is the most important clue. It's a diagnostic code from the motherboard, trying to tell you exactly what is wrong.

Based on the service manuals for your HP ProDesk 600 G6, those blinks are almost certainly a pattern of long and short flashes.

1. The Most Important Step: Decode the Blinking Light

Please plug the PC back in and observe the yellow light very carefully. It will likely flash in a two-number pattern (e.g., 3 long flashes, then 2 short flashes, then a pause).

Please count the pattern and match it to this list:

• 4 Long, 2 Short: This means a CPU over-temperature condition was detected. This fits your symptoms perfectly (it ran for 30 minutes, overheated, and shut down). It now refuses to boot to protect the CPU. This could be due to a failed CPU fan or dried-out thermal paste.
• 3 Long, 2 Short: This indicates a memory (RAM) error. This is also very common and often fixable.
• 3 Long, 4 Short: This indicates a system board power failure (a short circuit or "crowbar" event). This also fits the "light on only when pressed" symptom.
• 3 Long, 5 Short: This indicates a CPU initialization error.
  Here is the hp article which describes all beep codes 
  https://support.hp.com/us-en/document/ish_1997210-1528385-16

2. What to Do Next

Here is a step-by-step plan. Try these in order.

Step 1: Perform a Hard Reset (Power Drain)

This clears any stuck electrical states from the motherboard.

1. Unplug Everything: Disconnect the main power adapter from the back of the PC.
2. Disconnect Peripherals: Unplug your keyboard, mouse, monitor, all USB devices, and the network cable.
3. Drain Power: Press and hold the power button on the front of the PC for at least 20 seconds.
4. Wait: Let the PC sit for a minute.
5. Reconnect: Plug in only the power adapter and the monitor.
6. Test: Try to turn it on. If it still fails, observe the yellow blink code again.

Step 2: Check Your Power Adapter

• Ensure you are using the original HP adapter that came with the PC (or an identical replacement). A lower-wattage adapter might not be able to power it on.
• If your power adapter "brick" has an LED light on it, check if it's on. Does that light go out or flicker when you plug the cable into the PC? If it does, that signals a short circuit in the PC.

Step 3: Reseat the RAM (If you are comfortable)

If the blink code was 3, 2 (Memory Error), this is the most likely fix.

1. Unplug the PC and open the case (usually by removing a single thumbscrew on the back and sliding the top cover off).
2. Locate the RAM module(s) (they look like small green circuit boards).
3. Push open the small metal clips on either side of the RAM stick. The stick will pop up.
4. Pull the RAM stick out.
5. Firmly push it back into the slot until both side clips click back into place.
6. If you have two sticks, try removing one and booting, then swapping it for the other. A single stick might have failed.

Step 4: Replace the CMOS Battery

There is a small, silver coin-cell battery (a CR2032) on the motherboard. If this battery dies, it can cause all sorts of strange boot-up problems. These batteries are very inexpensive. You can try replacing it as a last resort.

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My Final Recommendation

1. First, identify that blink code.
2. If the code is 4, 2 (Overheating), the PC likely needs professional repair (a new fan or thermal paste).
3. If the code is 3, 2 (Memory), try Step 3 (Reseating the RAM).
4. If the code is 3, 4 (Power Failure), or if none of the steps work, this unfortunately points to a failed motherboard.

Given that the light only stays on when you hold the button, it is very likely a power fault on the motherboard (code 3, 4) or a CPU over-temperature safety override (code 4, 2).

Hope helps resolve your issue. Please, do let me know if you need any help, will be happy to assist you🙂

Good Day ahead!