the ic501 i have hundreds in stock new originals and you don't easily test the ic chips (i personally just replace with known good and socket it because my time is worth something, i don't test most ic if i have narrowed it down to a very high probability of an IC failure it gets replaced).
check the traces for cracks is only checking for continuity along all traces to find where you have a crack. i personally start out checking in the ohm mode with the beeper so i don't have to watch the meter constantly, BUT unless you have a full break you will be rechecking because the beeper will beep even if you don't have perfect continuity, so use your preference.
check the traces for cracks is only checking for continuity along all traces to find where you have a crack. i personally start out checking in the ohm mode with the beeper so i don't have to watch the meter constantly, BUT unless you have a full break you will be rechecking because the beeper will beep even if you don't have perfect continuity, so use your preference.
