Sony Alpha A7 IV Autofocus Not Working: Diagnosis and Solution

⚠️ SAFETY WARNING / FIRE HAZARD. This device contains lithium batteries. Improper puncturing or bending during disassembly can cause explosions or flames. The intervention requires precision and specialized technician assistance is recommended. ReeFix provides this diagnosis EXCLUSIVELY for educational and informational purposes.

IF "Lens communication failed" with ONLY ONE lens

• Probability: Lens-specific issue (65%), dirty/oxidized contacts (25%), camera body issue (10%).
• Key signs/indicators: The error occurs exclusively with a single lens, while other lenses work correctly on the same Sony Alpha A7 IV. Autofocus and eye-tracking are disabled only with that lens.
• Quick checks:
  1. Contact cleaning: Meticulously clean the electrical contacts of both the faulty lens and the Sony Alpha A7 IV camera body mount. Use a Microfiber lens cleaning cloth and, if necessary, an Electronic contact cleaner spray. Let dry completely.
  2. Visual lens inspection: Carefully check the contact pins on the back of the lens for signs of bending, caked-on dirt, or obvious oxidation.
  3. Remounting: Ensure the lens is securely mounted and correctly locked, without excessive play.
• Counter-examples: If after cleaning and inspection the lens continues not to work and other lenses do, the problem is almost certainly in the lens itself.
• Common mistake: Using cotton swabs that leave residue or non-specific cloths that can scratch the contacts. This can worsen the situation.

IF "Lens communication failed" with ALL lenses, autofocus and eye tracking absent

• Probability: Dirty/damaged camera body contacts (High, 40%), damaged FPC (Flexible Printed Circuit) of the mount in the camera body (Medium, 30%), physical damage to the mount (Medium, 15%), motherboard failure (Low, 10%), firmware (Very Low, 5%).
• Key signs/indicators: The error persists regardless of the lens used. The camera fails to focus or track the subject's eyes. The problem is clearly in the camera body.
• Quick checks:
  1. Camera body contact cleaning: Clean the contacts of the Sony Alpha A7 IV mount with a Microfiber lens cleaning cloth and Electronic contact cleaner spray.
  2. Visual mount inspection: Examine the camera body mount for any deformations, scratches, or stuck debris that could prevent proper contact.
  3. Reset and Firmware: Perform a factory reset of the camera. Check for and, if available, update the firmware of the Sony Alpha A7 IV. Sometimes a software glitch can cause communication errors.
• Safety notes: Do not attempt to disassemble the camera. Internal components such as the battery and flash capacitors can be dangerous.
• Often happens when... the camera has suffered an impact, even a slight one, on the mount, or has been used in very dusty or humid environments for prolonged periods, causing oxidation or wear.
• Technician output: The Sony Alpha A7 IV (ILCE-7M4) displays a "lens communication failed" error with every lens, rendering AF and eye-tracking inoperative. The most probable cause lies in the camera body: worn/damaged mount contacts, a faulty Sony Alpha A7 IV Flexible Printed Circuit for lens mount or, less frequently, a motherboard issue. A thorough visual inspection, continuity tests on the FPC with a Multimeter, and voltage checks on the communication circuits are recommended. Replacing the Sony Alpha A7 IV Lens Mount Contacts or FPC is a delicate procedure requiring a Precision screwdriver set and expertise.

THEN:

• If cleaning solves the problem: You can repair it yourself. The cost is minimal (cleaning materials).
• If the problem persists after cleaning and firmware update:
  • For a single lens: If the problem is isolated to one lens, consult a specialized lens technician or consider replacing the lens if the repair cost (often high for complex lenses) exceeds its value.
  • For the camera body (with all lenses): The problem is more complex and requires technician intervention. Repair costs could range from medium (contact or FPC replacement) to high (motherboard failure).

CONCLUSION:

If cleaning the contacts and updating the firmware do not resolve the error, consult a technician; if the repair estimate for the camera body exceeds 50% of the value of a new Sony Alpha A7 IV, consider replacing the device.