Hi I've got an Acer AL2021 monitor (1600x1200 resolution) that's starting to give me issues. The screen randomly dims, and then brightens up. It does this from switch on. From what I've read about this I'm pretty sure it's a capacitor issue and not a tube/inverter problem. Upon opening the case and removing some metal EMC covers, there are certainly 4 blown aluminium electrolytic caps. I will replace these, no problem. But my question is more about something else. The main board has a large chip with heatsink. The service manual does not show the heatsink which is simply glued on. Again, not an issue. But inside the EMC cover there is an orange foam square which contacts the heatsink when assembled. My immediate thought was that this was a thermal gap pad to conduct more heat from the chip. However, it feels warm to the touch and not cool/cold as the metal cover is. This is the bit that I don't understand. What is this foam pad for?
LCD Monitor
Dec 03, 2012
3 Replies
Stop the presumably earthed EMC shielding contacting the heat sink that might be at a differnt potential or not want to be earthed.
Stop the EMC shielding vibrating or rattling against the heatsink.
Stop the shielding getting distorted by bad handling.
Ta.
The heatsink seems to be electrically isolated from everything. The chip does not have an electrical connection on the top.
The heatsink is 6mm from the EMC shield.
Perhaps. Still looks like it should be a thermal pad to me.
[PS Sorry about my quoting style. I'm forced to use Windows Live Mail at the moment]
show us a pic, too many unknowns otherwise.
NT
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