Folder with question mark on Mac? 12 Ways to fix it
IT-Tech Online Fix Folder with question mark on Mac Get a Free Quote After years of flawless performance, your Mac has encountered an unexpected issue and is unable to start up today. All you see on the screen is a Mac folder with a question mark. But don’t panic! Before seeking professional help, follow this […]
Intel Mac CPU Vcore: PPVCC_S0_CPU Power Sequence
Intel Mac CPU Vcore: PPVCC_S0_CPU Power Sequence Last updated August 15, 2026 This component-level guide explains how an Intel Mac creates the CPU Vcore rail PPVCC_S0_CPU after the S3 and S0 power rails have passed validation. It uses the 2015–2017 13-inch MacBook Air A1466 logic board and 820-00165 schematic as the principal reference. Quick answer […]
Intel MacBook PM_SLP_S4_L Missing: Power-On Sequence and Diagnosis
Intel MacBook PM_SLP_S4_L Missing: Power-On Sequence and Diagnosis PM_SLP_S4_L is one of the most useful checkpoints on older Intel Mac logic boards. If PP3V3_S5 is present but PP5V_S3, PP3V3_S3 or the memory rail never appears, this signal helps identify where the power-on sequence stopped. However, a 0 V multimeter reading does not automatically prove that […]
Why Apple Service Centres Won’t Fix Your Logic Board
Have you ever visited an Apple authorised service centre just to be told your MacBook is unfixable? It happens quite frequently, and this is because the MacBook’s logic board is faulty. This page will explain why Apple authorised service centres cannot fix faulty logic boards and about Apple centre logic board repair. Mac Repairs Dependence […]
Spilled water on MacBook? Here’s what to do
IT-Tech Online Spilled water on MacBook? Here’s what to do Your MacBook has encountered a common mishap – water spillage, leading to unresponsive keyboard and trackpad, and even an automatic shutdown. What to do now? Spilled water on MacBook is a very common Mac disaster. Don’t worry. Follow this step-by-step guide to save your liquid […]
How does My Macbook Power up
How does my MacBook power on? 1. Once you connect MagSafe power adapter to the Mac, the System Management Controller (SMC) will talk to the chip on the MagSafe and the green light turns on. 2. The charging circuit receives power from the Magsafe and starts charging the battery if it is not fully charged […]
How does Macbook Power on
How does a MacBook power on? (For computer technicians) 1. An always-on PP3V42_G3H 3.42V power rail is created directly from an internal battery or a charger. This power rail powers the System Management Controller (SMC). The Mac is in “off mode” (G3) but the SMC keeps scanning the keyboard power-on button and Magsafe connector for […]
Intel Mac Power-On Sequence: MagSafe to Stable PPBUS_G3H
Intel Mac Power-On Sequence: MagSafe to Stable PPBUS_G3H Last updated August 15, 2026 This component-level diagnostic guide explains the early power-on sequence used by older MagSafe Intel Mac logic boards built around an ISL6259 or ISL6259A-type charger controller. It starts when a charger is connected with the battery disconnected and ends when a stable PPBUS_G3H […]
MacBook Pro graphics issues and their causes
This article is for MacBook logic board component-level repair professionals, written by IT-Tech Online, the MacBook repair specialist in Melbourne, Australia. Faulty GPUs are the main cause of graphics issues. This is especially true for the MacBook Pro 2011 A1286 AMD graphics chip. For other MacBook models, this may not be the case. Any of […]
How to Shut Down Water Damaged Mac
How to shut down a water-damaged MacBook If you spilled a glass of water on your MacBook while it is on, you need to switch off the MacBook immediately after the spill and never turn it on again. Follow this instruction to ensure your beloved MacBook is repairable and at a much lower cost. Hold […]
