Do you trace signal paths or read schematics block by block?

I find that relying purely on signal tracing from the input is too slow for big boards, expecially power supplies. I prefer the chunk-scanning approach you mentioned, but I focus my scan on identifying the main functional blocks first. For a motor controller for example, I always locate the main microcontroller and then imediately look at the massive electrolytic capacitors connected to the input voltage rails. If those aren't right, nothing else matters. My habit is to think of the schematic as a map and the power rails as the major highways. I follow the power lines from the input stage to the processor and then follow the output lines from the processor to the physical driver. I don't look at every tiny resistor in between; I look for the major functional transitions, like where the signal leaves the chip and hits the H-bridge transistors. This gives me the big picture before I worry about signal integrity. I have found that having a large print out taped right next to where I am soldering is much faster than squinting at a tablet. It allows me to physically point at a line and see its connection to the next part. It just helps when you are trying to find a weird parasitic loop or a mismatched trace to check for a short circuit during testing. It is much more visual that way.

I think the approach of starting at the central processor first, which was mentioned earlier, misses a critical piece of the puzzle when you are realy trying to debug something complex. If you begin with the microcontroller and then try to trace where its signals go, you often end up following dozens of tiny, meaningless connections untill you hit a major power plane. It is far more useful to start at the outside of the board. I prefer tracing from the input connectors or the output pins, treating those as the fixed constraints of the system.

By starting at the peripheral ports, I am immediately forced to identify the required voltage rail and the signal flow constraints before I even look at the central logic. For example, if I am looking at a sensor interface on a custom board, I immediately check the I/O lines for their voltage requirements, perhaps 3.3 volts, and then follow that specific power path inward to see what regulator feeds it. This boundary checking is much faster than waiting for the brain to tell you what it needs. I usally use a multimeter to check the actual rail voltages on the PCB edge to make sure the schematics match the physical reality. It is a bit counterintuitive because you are moving from the observable effect back to the cause, rather than the typical signal flow. But for reading dense designs, knowing the system requirements first saves a huge amount of time compared to just looking for the big chip.

I skip the input trace entirely too. Instead, I look for the main functional blocks based on what the components look like. The switching stage, for me, is always the easiest anchor. It has a specific grouping of big inductors and power transistors that mark where the heavy lifting happens. Once I find that section, I can look at the pins coming off it to see exactly what signal needs to go next. This helps me understand the architecture without wasting time following every tiny trace. Does anyone usually group by power density or functional block like this?

I keep getting confused by all the tiny lines connecting things inside the big boxes. When I look at the diagram, I usually just see a bunch of symbols and don't know which ones are really important compared to others. It feels like there are thousands of connections and I'm missing the main pathways. I've started trying to trace the signals by following the part numbers instead of the actual lines on the page. I guess when I look at the drawing, I shold be focusing more on the function of the specific parts shown there. Is there a better way to group the components so the flow of the signals makes more sense to me?

I've been having the exact same problem with some industrial sensors I'm testing out lately. When I look at the schematics, it feels like I should be able to see the whole picture, but all I get are these dense blocks of wiring and symbols. I'm trying to figure out how to stop looking at the lines individually and start seeing the big functions of the circuit. It's hard to know wich part is the 'brain' part versus just the power distribution. I think what I need is a trick to organize my focus when the diagram is this big. Since you guys are finding success with chunk scanning, how do you decide where to start scanning if the schematic doesn't have clear headers or blocks? I feel like I might be skipping the most critical sections entirely.