Louis Rossmann's rants, tips, and ideas on the laptop repair industry.

Amtech NC-559-V2-TF flux for sale!

Posted Sunday, December 27, 2015

In most of my motherboard repair videos, the flux I am using is Amtech NC-559-V2-TF. A lot of people have asked what flux I am using because it makes the job so much easier. Even if I tell you what it is, I have not done the hard part of your job in locating Amtech NC-559-V2-TF! Read More

What is error 53?

Posted Friday, October 2, 2015

Error 53 is something often discussed online, without much information. Some think it is just an issue when you change the home button on an iPhone 6 or 6+. It isn’t. You can get error 53’d even with the original home button. Error 53 is Apple’s way of monopolizing the repair of their products at Read More

Common onewire circuit ailment on older Macbook Pro logic boards.

Posted Friday, June 5, 2015

One of the common issues is that liquid gets in along the vent and touches the board since there is no protection, and there are components along the vent that are very important. The onewire circuit is what allows the charger to speak to the SMC so it can give it the go-ahead to allow Read More

What is a voltage divider?

Posted Tuesday, May 5, 2015

A voltage divider is a series of two resistors one can use to lower an input voltage to your desired voltage. Let’s take the BKL_EN circuit, for example. Many circuits inside of a laptop don’t come on until they see voltage at their enable pin – think of the enable pin like their power switch. Read More

Explanation of PP3V42_G3H power line on Macbook Pro logic board

Posted Sunday, April 19, 2015

In the past blog, I discussed the onewire circuit. Here I’d like to talk about a specific power rail, that powers the onewire circuit, and its importance.   The PP3V42_G3H power rail is one of many power rails on a Macbook Pro logic board. ignore the confusing nonsense lik PPV and all that – PP3V42_G3H means 3.42v. Read More

The onewire circuit’s importance to Macbook logic board repair.

Posted Friday, April 17, 2015

If the onewire circuit does not work, the charger will only output limited power to the board, and nothing will work off of the charger. The onewire circuit depends on proper function of the battery charger chip, the SMC, and the two ICs that are utilized in the onewire lines. Common issues with the onewire Read More

BGA rework video using ZM-R6200C for Macbook logic board repair

Posted Thursday, April 16, 2015

Not relevant much anymore since Apple is covering these failed GPUs for free, but I figure it may be of interest to some how the work is performed. Here you’ll see me remove the old chip, prepare the board for a new chip, and install the new chip. This process is a bit of a Read More

What is the importance of a diode mode measurement in troubleshooting Macbook logic board circuitry?

Posted Tuesday, January 13, 2015

What makes diode mode measurements different from resistance mode measurements? Diode mode measurements allow me to quickly get an idea of what the entire circuit is doing and compare it to a known working board. Diode mode measurements are very similar to resistance measurements, but they are much faster. Resistance is measured in Ohms, and Read More

Is it right to take an iPhone 6 to Apple to get it fixed for a customer?

Posted Sunday, December 28, 2014

Apple replaces the screen to the iPhone 6 for $109. There is a lot of talk in the iDevice repair industry on whether it is ethical or not to take a phone from the customer, then bring it to Apple and have them fix it, while taking a middleman fee of $50 to $100. In Read More

Employee management 101; look for patterns, not excuses!

Posted Wednesday, December 24, 2014

From an employer’s perspective, it is important to hire people who will produce for your business. You’re going to find a lot of employees that come up with excellent reasons as to why they were unable to accomplish a task. What I suggest new employers, managers, & business owners do is avoid judging excuses on Read More