Taz 4 not boot, please help


today I did a duo fan mod for my taz 4 and when I made fan run 100%, there is some loud noise so I turn off the power. After that when I turn the power on the LCD light is on but it just show blank screen.

I think the LCD screen is broken so I replace it with a new one but it also doesn’t work so I change new Rambo board bought from Lulzbot store but it still show blank screen.

does anybody have some ideas why changing both new LCD screen and Rambo does not solve this problem?

When you replaced the RAMBo did it come with new fuses or did you reuse the fuses from your older RAMBo board? This sounds like a blown fuse to me. You could try swapping the F2 and F3 fuses on your board and see if the LCD screen comes on, if it does that will mean the fuse was the issue. If that is the issue you can buy a replacement here: https://www.lulzbot.com/store/parts/5-amp-nano-polyfuse-x3

Yes the new RAMBo comes with new fuses. Anyway I got it solved now, what you have to do is install firmware into it. I got confuse because the symptom after replaced the LCD and RAMBo board is the same as the old broken board. Also I expect some firmware to be pre-installed on the new board as I bought it from Lulzbot. I thought the board is broken and nearly buy another one.