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A1990 Macbook Pro Not turning on Repair


A1990 Macbook Pro Not Turning On Repair in Adelaide, caused by a short on the logic board. We have located the fault and replaced the faulty component. While Apple Authorised Repair Centre offered a complete logic board replacement to the customer.

This article is not educational material. It is instead a showcase of the services we offer.

Therefore, it should be used as general guidance on what to expect from such repairs.

In case you have a similar device and need repair, always rely on professionals. These are sensitive electronic devices, and small mistakes may cause irreversible electronic damage, requiring whole part replacement for 2 or 3 times the cost of the Repair.

Do not Risk Damaging your Device – Book this Repair with us Today!

A1990 Macbook Pro Not Turning On Repair

Spotlight of this week’s repairs is this A1990 Macbook Pro Not Turning On Repair. When we look at the Macbook, although it’s a 2018 model, it looks like it has just been bought new.

ITSolve Repairs specialise in Macbook Repairs in Adelaide

Identifying fault on 15" 2018 Macbook Pro A1990
Identifying fault on 15″ 2018 Macbook Pro A1990

IT-Solve is the leading Macbook Repair Centre in Adelaide. Our workshop is equipped with state-of-the-art troubleshooting and repair equipment. We can identify and replace those failed individual components instead of the complete motherboard of the Macbook.

This was exactly what this user had been advised when they went to the Authorised Apple Repair Centre here in Adelaide. The quote was close to the replacement value of the Macbook. No wonder why more and more people just buy a new one instead.

Perhaps that’s Apple’s way of selling more Macbooks and generating more e-waste. But it is staggering the mindset damage it does to people. Who leaves Apple Genius Bar convinced that they need a new Macbook every two years!?

Locating Fault on A1990 Macbook Pro Not turning on Repair

Macbook Pro Not turning on with USBc Meter stuck at 5V 0.02A
Macbook Pro Not turning on with USBc Meter stuck at 5V 0.02A

When we connected the Macbook to our USBc meter charger, we could immediately detect that neither charging nor turning on circuit was initiating. The Macbook is stuck on 5V 0.02A. This tells us that the USBc chips, which are CD3215C with this model, are not negotiating the PD protocol. Either one or more of them is faulty. Alternatively, they detect a short circuit down the line and enter protection mode.

A1990 Macbook Pro Not Turning On Repair
A1990 Macbook Pro Not Turning On Repair

Later one is easier to detect and resolve, so let’s start with that. We can start measuring the fuses and big coils first, as they are on the major artillery lines.

A1990 Macbook Pro Not turning On – Identifying fault location

Detected a short circuit on the PPBUS_G3H line of A1990 Macbook Pro Not Turning On Repair
Detected a short circuit on the PPBUS_G3H line of A1990 Macbook Pro Not Turning On Repair

Straight forward, we located a dead short on the Macbook’s PPBUS_G3H line, this indicates a shorted component on this line. However, the PPBUS_G3H line is one of the most populated, and thousands of components must be hanging on this branch.

An easier way to locate it is to disconnect the PPBUS_G3H line from more sensitive parts of the circuit by lifting up the fuses and injecting voltage into the line.

Video of locating a short circuit on a Macbook Pro with an IR Thermal Camera by Injecting voltage

By following Ohm’s law, with such low resistance, we should get a component emitting heat when under stress. With thousands of components populated so densely on this board, it’s almost impossible to detect 60-70*C heat by touch. So we rely on our IR Temperature Camera to detect minor heat disturbances.

A1990 Macbook Pro Logic Board ready to replace the shorted capacitor
A1990 Macbook Pro Logic Board ready to replace the shorted capacitor

Long gone are days when fuses would blow or magic smoke escaping would indicate where the blown components were. Especially with short circuit protection on chips and constant current sensing lines all over the place, they all go into protection mode when there is some disturbance in the force.

A1990 Macbook Pro Not turning On Repair Process

Video of Locating and Replacing shorted Capacitor on Macbook Pro A1990

We located and replaced the shorting capacitor, which seemed to draw all that current through itself. Hence it was glowing like a bulb.

Macbook Pro communicates as expected with USBc and turns on
Macbook Pro communicates as expected with USBc and turns on

Looking at the USBc meter now, PD protocol communication is achieved and provides 20V as expected.

Quick test Macbook Pro after repair
Quick test Macbook Pro after repair

The next step is to check quickly before we assemble for further tests. Once it turns on and all seems fine, we can go ahead and assemble it.

Successful A1990 Macbook Pro Not turning On Repair

A1990 Macbook Pro Repaired and Diagnostics passing
A1990 Macbook Pro was Repaired, and Diagnostics passing

Running all diagnostics yielded a successful result. So we were good to go and test the remaining of the system.

After a couple of hours of testing, we could see the repair was successful, so we could inform the customer.

The root cause of A1990 Macbook Pro Not turning On Failure

A1990 Macbook Pro Not Turning On Repair
Successful A1990 Macbook Pro Not Turning On Repair

In final words, this Macbook was barely used for anything else than a media system. Most likely with a closed screen on a desk connected to a media system, if we had to guess. Considering that it has such a powerful GPU and CPU – it emits lots of heat. Although it was not much dusty inside, the closed system generated lots of heat which could not escape quickly enough. Add on that prolonged streaming they tend to heat and stress those filtering capacitors on the logic board.

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Do you need this Repair in Adelaide?

If your Macbook or Laptop is causing trouble and you need a Laptop & Macbook Repair Service in Adelaide, give us a call, and we will advise on the best scenario to get your Device repaired.

We at IT-Solve, specialise in Mac, Laptops and Electronics Repairs. We will do our best to repair your Device quickly without involving high costs and long waiting times in Repair shops. Our average repair takes under a week!

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Repaired, not Replaced!

We are committed to reducing e-waste in Australia. We do it by educating our customers on the reparability and longevity of their devices, as well as providing affordable Laptop and Macbook Repairs here in Adelaide.
Although our best intentions and hard work, this is not an easy task. Customers must accept that cost of high-quality electronic repairs is between a third and half of the price of a new device. However, with the current trend of planned obsolescence in electronic design, we see more and more Laptops having shorter lifespans. To tackle that, while we do our repairs, we target common planned obsolescence engineering design mistakes to ensure we extend the life expectancy of the Laptops we Repair. Check some of our Repair Cases to get an idea of the process.

That said, if we buy a new one or write it off via insurance, it does not guarantee that the new one will not meet the same fate as the older one pretty soon.

Quite often, we see accidents reoccurring within less than 2-year gaps. So if we can save 2000$ or even 1000$ today by repairing our faulty Laptop or Macbook is brilliant. That’s an extra half cost of a Device, ready to be spent on another one. If the time comes or our need for performance changes.
When that time comes is up to us to buy a new one or keep pushing the one we have, but delaying it by a year or three is always a good starting point and saves another abandoned Laptop or Macbook from polluting our only Planet.

Check Other Repair Cases