my hp deskjet 2855e just flashes the power light and won't actually turn on, no display or anything.

Diagnosis

The flashing power light on the HP DeskJet 2855e, coupled with a completely dark display and lack of response, indicates a "Power-On Self-Test" (POST) failure. This occurs when the printer's internal logic board detects a critical error during the boot sequence, preventing the firmware from loading. The flashing light is a heartbeat signal showing the board has power, but the system is stuck in a boot loop. This state is most commonly caused by a "stuck" capacitor in the power supply or a corrupted temporary cache from a failed HP+ firmware update. Because the 2855e is an "e-series" printer, it relies heavily on a constant handshake with HP servers; if a network-triggered update was interrupted by a power flicker or signal drop, the printer can enter this unresponsive state. You can confirm this is a power-logic issue if the light flashes in a rhythmic pattern rather than a steady, solid blink, and if the printer does not respond to the "Cancel" or "Resume" buttons.

How to Fix It

To resolve a boot loop and force a hard hardware reset, follow these precise steps to drain all residual electricity from the logic board:

1. While the printer is still flashing, physically disconnect the power cord from the rear of the printer. Do not just turn it off via the button.
2. Unplug the other end of the power cord directly from the wall outlet. If you are using a surge protector or power strip, bypass it and plug the printer directly into a wall socket for the reset process to ensure a clean current.
3. While the printer is completely disconnected from all power sources, press and hold the Power button down for exactly 30 seconds. This forces the internal capacitors to discharge any remaining voltage that may be holding a "bad" state in the memory.
4. Leave the printer unplugged for a minimum of 60 seconds. This allows the volatile memory to clear completely.
5. Reconnect the power cord firmly to the back of the printer, ensuring the plug is seated deeply into the port.
6. Plug the cord back into the wall outlet.
7. Press the Power button once. The printer should now initiate a full boot sequence, and the display should light up within 10-15 seconds.

If That Didn't Work

• Perform a Cold Boot with Cartridges Removed: Sometimes a short-circuit in the gold contact pins of an ink cartridge can prevent the printer from booting. Remove both the tri-color and black ink cartridges. Attempt to power on the printer without them. If it boots and gives an "Ink Cartridge Missing" error, the problem is a faulty cartridge or contaminated contacts. Clean the gold pins with a lint-free cloth and 90% isopropyl alcohol.
• Test the Power Source: The DeskJet 2855e is sensitive to voltage drops. If you are using a power strip with multiple high-draw devices (like a space heater or gaming PC), the printer may not be receiving the consistent amperage required to initialize the print head. Plug the printer into a different circuit in a different room to rule out a faulty breaker or outlet.
• Force a Factory Reset via Control Panel: If the printer boots but immediately starts flashing again, press and hold the "Wireless" and "Cancel" buttons simultaneously for 5 seconds. This triggers a network reset which can clear corrupted HP+ cloud handshake data that might be crashing the firmware.
• Check for a Paper Jam "Ghost": A tiny scrap of paper lodged in the carriage path can occasionally trigger a sensor that halts the boot process before the display activates. Open the ink cartridge access door and use a flashlight to check for any debris or jammed paper fragments near the far right or left of the carriage path.

Heads Up

• Avoid Power Strips: HP recommends plugging the 2855e directly into a wall outlet. Low-quality surge protectors often cause "under-voltage" during the initial boot-up phase, leading to the exact flashing light issue you experienced.
• Firmware Updates: Since this is an "e" model printer, always ensure the HP Smart app is updated on your phone or PC. This ensures that when the printer does boot, it can quickly resolve any pending firmware patches that caused the crash.
• Ink Contact Maintenance: Never touch the gold contacts on the cartridges with your fingers; skin oils can cause a micro-short that prevents the printer from completing its power-on self-test.
• Power Cycling: If the printer freezes in the future, always perform the "unplug and hold power button" method rather than just toggling the switch, as this is the only way to truly clear the internal logic board.