Why should a south bridge need heating to start the computer ?

[david carey]

A friend spoke to me about a starting problem he has with a motherboard which is still under warranty but the vendor is being shy about replacing the board as he says there is nothing wrong with it after being presented with the motherboard in his shop . The computer apparently will only start if the southbridge is heated first - I am not sure why the chap thought of this but he assures me it is the only way to start the machine . Ambient temperature is usually over 75 F and not usually higher than 85 . Any insights on this ?

 

[Caring1]

Sounds like an excuse to me.

 

[R-T-B]

Couple that with the fact that southbridge is dated terminology (we've been using platform controller hubs for like the past decade) and I'm sure something stinks here.

 

[Fangio1951]

hi David,

Totally sus.... here in OZ we deal with vendors like this = "I'l be referring you to the Department Of Fair Trading" which usually (95% of the time) does the trick in getting them to replace it under warranty.

What country are u in ??

 

[Assimilator]

It sounds to me like we're talking about a motherboard so old that the solder on the BGA balls holding the SB to the board has started to fail thus breaking an electrical connection, and a little heat is enough to warm said solder to the point where it expands enough that connection is restored and the board boots. Which would fall under the category of manufacturing defect, and hence certain warranty replacement, in my book.

Seriously, how old is this board, and how is it still in warranty?

 

[dorsetknob]

The computer apparently will only start if the southbridge is heated first - I am not sure why the chap thought of this but he assures me it is the only way to start the machine

" If this was True then there would be some form of pre heater on the southbridge"
this is a pure salesman bullshit to allay the customers query.

as others have said Motherboard is dying and in need of RMA/replacing

 

[Flaky]

Probably the last platform consisting of NB+SB is AMD's AM3+ implementation. Some of these boards are still for sale, so the motherboard may still have valid warranty.

Any insights on this ?

The shop treats your friend like an idiot. Get this board RMA'd and never buy there anything again.

 

[david carey]

There is no " Department of fair trading" here unfortunately .
The chap uses his mothers hair-drier to heat the chip .
It is a an AM4 board , I believe .
I saw what he was applying heat to and and it looks like a southbridge ( it was a little dark , my eyesight is not so good and I did not have my working glasses on ) from the location , I know that the am4 platform does not have a conventional NB/SB anymore . I have no reason to doubt the young fellows remarks . I think he has taken the board back to the vendor today ( best of luck to him , getting them to honour their warranty - from my experience and this company is one of the oldest and largest here ! ) .

 

[dragontamer5788]

There's all sorts of heat-sensitive components on motherboards. I wouldn't know which one was causing an issue... but I'd imagine one of your heat-sensitive components was acting up.

A common one is called a PTC Thermistor, such as: https://www.tdk-electronics.tdk.com/inf/55/db/PTC/PTC_OC_Leaded_12V_24V_C935_C995.pdf

The way it works is rather simple and brilliant. It starts off with near 0 resistance, like a wire. As electricity flows through it, it heats up: cutting off the electricity. The idea of PTC Thermistors is to temporarily flow electricity through a junction on startup, and then suddenly stop when the Thermistor gets hot.

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If for some reason, your PTC Thermistor wasn't getting hot anymore, then the component would stop working. By heating up the thermistor, it temporarily sends the electricity where it needs to for that brief second, and then your computer boots up. (or something, I'm really talking out of my ass right now).