i recently got an abit ic7-g max ii off trashbay. all of the board's slots, connectors etc. all worked fine except for the lan. the board uses intel's csa gigabit lan chip (intel pro 1000 ct).
i noticed that the lan works on a cold boot. but as the board heated up, the lan started to cut out and the activity and speed leds kept turning on and off as if someone kept unplugging and plugging the cable. note that this is not the normal blinking when there is network activity.
on the lan connection software, it also kept cycling between "connection active" and "unplugged". it also does this when idling at the bios and in windows and linux, so its not the drivers. i changed many different lan cables and also checked the pins on the ethernet connector. no damaged or tarnished pins were found. there were also no obvious signs of scorching/heat damage or physically damaged components around the lan chip.
next, i touched the lan chip and noticed it was quite hot to the touch. i estimate the temp to be around 55-60°C. for some strange reason, when i put my finger on the lan chip, it seems to start working again. but when i put my finger away, it cuts out again and starts blinking.
at this point, im wondering if its a cracked solder joint or an overheating chip. i've never heard of cracked solder joints working when cold and failing when hot. so i went with the chip somehow overheating. could it be a bad mosfet beside the chip? i measured the voltage on the mosfet with a multimeter. the source voltage was 3.25v, the gate voltage was 1.2v and the drain voltage was 2.4-2.6v. doesnt look like a leaky mosfet to me. also doesnt look like excessive voltage causing the chip to overheat.
so i slapped a small aluminium bga ram heatsink with 3m thermal tape on the lan chip and blew two 80mm fans across the pci slot area. the lan chip now remains cool to the touch and no longer cuts out during heavy network activity. it should also be noted that the malfunctioning and overheating lan chip doesnt hold up the system from booting or anything. bios detects it fine and assigns it an irq. it just keeps working intermittently when it gets hot.
being a person with a medical background, im curious as to the root cause of why the intel csa lan chip is overheating. i have an msi 875p neo2 board with the same lan chip as the abit ic7-g but it has never had any problems with overheating. neither does it require a heatsink to work. any idea why the intel lan chip on my ic7-g is an overheating turd? i fear putting a heatsink on the overheating lan chip only tackles the symptom of the problem and not the root cause of the problem: why is the lan chip overheating in the first place? bad mosfet? lightning strike damage or high voltage surge over the lan interface from the previous owner? anybody experienced bga failure whereby things work when cold but not when hot?
i noticed that the lan works on a cold boot. but as the board heated up, the lan started to cut out and the activity and speed leds kept turning on and off as if someone kept unplugging and plugging the cable. note that this is not the normal blinking when there is network activity.
on the lan connection software, it also kept cycling between "connection active" and "unplugged". it also does this when idling at the bios and in windows and linux, so its not the drivers. i changed many different lan cables and also checked the pins on the ethernet connector. no damaged or tarnished pins were found. there were also no obvious signs of scorching/heat damage or physically damaged components around the lan chip.
next, i touched the lan chip and noticed it was quite hot to the touch. i estimate the temp to be around 55-60°C. for some strange reason, when i put my finger on the lan chip, it seems to start working again. but when i put my finger away, it cuts out again and starts blinking.
at this point, im wondering if its a cracked solder joint or an overheating chip. i've never heard of cracked solder joints working when cold and failing when hot. so i went with the chip somehow overheating. could it be a bad mosfet beside the chip? i measured the voltage on the mosfet with a multimeter. the source voltage was 3.25v, the gate voltage was 1.2v and the drain voltage was 2.4-2.6v. doesnt look like a leaky mosfet to me. also doesnt look like excessive voltage causing the chip to overheat.
so i slapped a small aluminium bga ram heatsink with 3m thermal tape on the lan chip and blew two 80mm fans across the pci slot area. the lan chip now remains cool to the touch and no longer cuts out during heavy network activity. it should also be noted that the malfunctioning and overheating lan chip doesnt hold up the system from booting or anything. bios detects it fine and assigns it an irq. it just keeps working intermittently when it gets hot.
being a person with a medical background, im curious as to the root cause of why the intel csa lan chip is overheating. i have an msi 875p neo2 board with the same lan chip as the abit ic7-g but it has never had any problems with overheating. neither does it require a heatsink to work. any idea why the intel lan chip on my ic7-g is an overheating turd? i fear putting a heatsink on the overheating lan chip only tackles the symptom of the problem and not the root cause of the problem: why is the lan chip overheating in the first place? bad mosfet? lightning strike damage or high voltage surge over the lan interface from the previous owner? anybody experienced bga failure whereby things work when cold but not when hot?
Attached Files
so i dont need the throughput of gigabit ethernet.
will have to watch it before applying power!
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