Resposta para "How to fix "vertical lines" on my iMac 27 late 2009"Hi there, i've seen this several times on different iMac's (all 27 inch models). It seems it only happens on the models with a v-sync flatcable. The later models with a "normal" connector and separate wires seems not to be affected. At the moment i have an iMac with the same vertical lines with the additional problem that the whole screen goes black after a few days. When i pust the power button 2 times (standby and out of standby) the screen appears again. The external monitor is not affected and keeps playing when the internal scheen goes black. Already did a reflow of the GPU and changed the inverter board but no difference.