Hello all! So a few months ago, I got a buncha old Macs from my uncle: a Macintosh 128k, a Macintosh (can't remember which model, it looks very similar to the 128k), and a Macintosh SE. The last two machines run fine, however the 128k is giving me some problems. Whenever I turn it on, it gives me this checkerboard pattern thing, and never does the boot-up chime. I have already done some research on this problem. Some people said this is a problem with the resistors on the logic board, and that I should wash (one person even said to put in a dishwasher) the logic board. I didn't know if this applied to me, as they were referring to a SE/30. Then, someone said to swap out the logic board with a similar computer that works. So I swapped the logic boards of the 128k and the second computer from the list (not the SE). At first I thought it worked, as I heard the boot-up chime, but then I saw nothing on the monitor. I thought it was just the logic board being incompatible with the CRT monitor or whatever, so I swapped the logic boards back. The thing is, when I turned it on this time, I also got no video, whereas I used to get that checkerboard pattern. I also got no boot-up chime. Now I'm kinda nervous that I may have done something to damage the CRT. Then again, I know those CRTs use a lot of electricity, so I'm not sure if I need to leave it plugged in for a while to let electricity get in or something. I'm a huge Apple fan, and would love to see this thing working again, so if anyone can offer any advice, it would be much appreciated!