Few moths ago I purchased on Ebay as described "working in perfect condition Amiga 600 motherboard". I didn't opened package until today. I was surprised, something was wrong with motherboard, display turns purple, problems with IDE controller. After little investigation and visual checking of some components I discovered that something is wrong with Denise chip. Moving my hand over the Denise chip caused disturbance on my monitor so I was thinking it must be cold solder joint or micro fracture somewhere near the chip. In the same time I realized one disturbing fact "How much Amiga motherboards ended in garbage because some simple problems we could fix in few minutes". So this video shows how to discover cold solder joints on this specific chip without any additional tools. My soldering technique was not so professional because I needed to leave motherboard in specific position to get this on video.