[Adrian] has a good deal of retrocomputers, so he utilizes an RGB to HDMI converter to drive contemporary monitors. In certain, he has a box that makes use of a programmable logic chip to read a variety of RGB alerts and ships them to a Raspberry Pi Zero to push the HDMI output. Appears terrific until finally, of program, a thing goes incorrect.
A converter that had labored stopped functioning thanks to a terrible board with the programmable logic chip on it. Unlike the retrocomputers, this board has minimal little surface area mount parts. A tiny assessment prompt that some of the chip pins were not accepting inputs.
The Xilinx device has 5V-tolerant inputs and [Adrian] thinks that 5V inputs may possibly have fried the inputs which can come about if there is 5V on the pin and the device is not driven up. The approach was to take out the undesirable chip and switch it with a new just one.
As SMD sections go, the Xilinx chip is not specifically little, but if you are much more accustomed to working on 1980s computers, it can be a little bit of a problem. [Adrian] sensibly utilised a large amount of flux and hot air to eliminate the portion. We may possibly have included the adjacent elements with Kapton tape to keep away from using off far more than we required.
Yet another idea is that if you are certain the part is lousy, it is sometimes a lot easier to reduce all the potential customers off, dispose of the chip, and then take away each and every pin one particular by a single. He got it, while. We might have cleaned the pads ahead of resoldering them, but [Adrian] elected to just increase contemporary solder and that did function but the excessive solder made it harder to put the new chip.
It took a couple attempts, but persistence is the key. Luckily, the board was substantial top quality and took a lot of warmth as properly as the section. If you are timid about doing SMD do the job, you may well discover [Adrian’s] journey inspirational. It does support that he has a terrific microscope. In the end, it labored despite some difficulties with the video clip capture triggering some confusion on colours.
This isn’t actually a tutorial on SMD rework, but extra of a 1st-time diary. If you want a thing more tutorial, test out [Bil Herd’s] publish. Or, spend an hour with [Moto Geek].