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flat mac ilamp bad pic after 1 hour or so
- Thread starter galaga
- Start date
What kind of bad pic?
The G4 lamps are old enough now to be developing problems inside their LCD monitors. You can find threads about troubleshooting the monitors and there are some caps or controller boards that can be replaced. But first, try an external monitor (via mini-VGA port) to see whether the GFX chip is the problem or not.
PSU can also be a problem if it has not been kept clean - it can gather fluff and overheat. If you don't want to get inside the machine, you can first try vacuum cleaning with a rubber tube around the grille at the bottom of the neck. Best is a thorough disassembly and clean of all parts. You can find good visual guides online with a simple search.
Beware that common cause of GFX chip failure is that the baseplate of the lamp has not been kept properly tightened. The baseplate is the heatsink for that chip and several others. If the chip loses firm contact with the heat-transfer pad on the base, you can lose the chip. Then you will have to search for a new motherboard unless you are a professional - replacing the chips is not for amateurs in my (amateur) experience.
Rick
The G4 lamps are old enough now to be developing problems inside their LCD monitors. You can find threads about troubleshooting the monitors and there are some caps or controller boards that can be replaced. But first, try an external monitor (via mini-VGA port) to see whether the GFX chip is the problem or not.
PSU can also be a problem if it has not been kept clean - it can gather fluff and overheat. If you don't want to get inside the machine, you can first try vacuum cleaning with a rubber tube around the grille at the bottom of the neck. Best is a thorough disassembly and clean of all parts. You can find good visual guides online with a simple search.
Beware that common cause of GFX chip failure is that the baseplate of the lamp has not been kept properly tightened. The baseplate is the heatsink for that chip and several others. If the chip loses firm contact with the heat-transfer pad on the base, you can lose the chip. Then you will have to search for a new motherboard unless you are a professional - replacing the chips is not for amateurs in my (amateur) experience.
Rick
Yes, have a look here:
viewtopic.php?f=2&t=18405
The GC is probably overheating, the best way is to remove the logic board, clean the area and use new thermal paste (a kit was formerly available to renew both thermal pads, but you can probably do without)
This is a good reference - thanks for the thread link.
I would add that there are four screws fixing the logic board to the baseplate. Three metal screws near the perimeter, and another NYLON screw nearer the centre. This functions to ensure good contact between those ICs under the logic board and the thermal conducting pads that link to the baseplate as heatsink. Over time, those pads shrink to fit the shape of the chip that is pressing down on them. So anything less than a good pressure from the screws, including the nylon screw, can mean a weak contact between chip and pad. If concerned about this, you can buy slabs of the thermal conductive pad material (make sure to get correct thickness) and cut them to shape to replace any that do not give a firm contact. Usually, the thermal paste will be sufficient.
Rick
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