To the person who found my blog my searching for “where is the power button on ibm x3400″:
Behind the front cover (you have to remove it – it pops off on the left-hand-side), in the top-left, immediately beside the power light, as below:
It's the white button beside the green power light
[...] you came here looking for information on where to find the power button on an IBM x3400 or x3500, check this post instead. (Continued from Part [...]