Dead Fan OR Motherboard OR CPU? (Fujitsu Amilo PA 3553)

I have a Fujitsu Amilo PA 3553. When I push the power button I have the power light on, the webcam light on and can hear the hard drive fan on. Other than this I get nothing. No screen, no beeps, no POST behaviour - NOTHING. This includes the main fan which doesn't even turn in the slightest when I power on.

After about 10-20 secs of nothing-ness - the system shuts off automatically.

I've tried all the various tricks (holding power button reset, removed CMOS battery, removing RAM, HD, alternative monitor, etc.) but no luck. I do not get any beeps even with RAM removed.

I was given this laptop diagnosed as a dead motherboard but I've got a sneaking suspision it might just be the fan that needs replacing. I put a voltmeter on the fan connection on the motherboard and turned laptop on - meter read about 4.6/4.7 volts (prob not entirely accurate as tricky to put a meter on such a small item) which in my eyes means the fan should be on but it isn't spinning.

So assuming the fan is dead - would this cause the system to be acting like I've described above or do you think it could be a bit deeper. I've had one person say that if it is a dead fan, the CPU/Motherboard could have fried itself at the time it died.

Any suggestions?

 

Hello, Debbie, welcome to NBR.

Probably, i know some systems act like this if one of the fans is faulty.
I'm not You could probably look into replacing it by searching online its part number written on the back.

 

Hi, thanks for the reply.

Tried a different fan last night but checked the wiring and wasn't the same so didn't work.

Seen a few 2nd hand ones on ebay starting at around £8 which I know isn't much but I don't want to start splashing cash on something pointless (hence I'm here on the forums!).

It seems the wiring on the Fujitsu fan is not very common so my only option seems to be to buy the exact replacement I need to test if it works.

Just wired up a known working fan with correct wiring but this one also doesn't spin. I'm beginning to think this is a dead mobo/cpu but as there is a voltage coming from the fan plug (as per my inital post), why would a working fan not spin?

 

Do you know the specifications of the fan you just tried?
Maybe it needs more power to start spinning.

 

This is the fan in my Amilo...


And this is the fan I tried (from an Acer Aspire 5536)...


As far as I can see they are the same spec fan (both DC5V and both wired the same). It seems it is just their shape that differs but I may be wrong???

 

I agree with the initial assessment as provided by whoever gave you the laptop in the first place. It does sound like a dead motherboard to me. If the problem were just the fan, the laptop would still try to run, booting up into your GUI. The Amilo Notebook is a good system, despite it's nightmare maintenance issues. Take it from my own laptop - which still runs relatively smoothly regardless of it's dying fan.

The laptop boots up, and runs without issues, until the temperature rises to critical, then it auto-shuts off. Of course, I just need to whack it one for the fan to kick in before this happens - a problem I'm hoping to deal with as soon as the replacement arrives in the mail.

If yours isn't even getting a whimper of a response, then it's most likely the board that's the problem. In which case, time to get a new laptop, I'm afraid.

 

I think you are right. Since my last post, I've attached a stand alone battery pack to the fan which is sending out about 4.8V and the fan spins perfectly. The thing that confuses me is that the same two connections on the motherboard are sending out 5V to the same to wires and nothing??? Forgetting dead motherboards - basic electrical knowledge gives no reason for the fan not to spin???

I even had a thought that the third wire (I think its the yellow one) was somehow getting a message from the mobo not to spin even though it was getting the voltage it needed. Tried disconnecting and still nothing so it wasn't that either.

So frustrating but as you say, even with the fan not spinning I would expect to get some (if not brief) life out of it. It was just my thinking that the system may be checking the fan straight away, detected nothing and went no further. So annoying but think I'm just going to sell it for spares - too much for my little brain to cope with!

 

A common problem with PA 3553's seems to be the northbridge overheating due to the heatsink actually not getting into contact with it.
Although in this case the fan would still go on momentarily upon power on, the laptop would shut down in a few seconds.
The following is worth trying:
Clean and replace the paste on the chips and place a cleaned and thermal pasted 1p coin or any ~1/2mm thick copper plate between the heatsink and the northbridge chip (middle one between CPU and GPU). It will be a tight squeeze but that's what you need to press the chip down and the brackets will take some of the load off.
It worked on two different PA 3553's for me. It's a temporary fix but if it works, you can eventually reflow or reball the northbridge if it would fail again.

Hope it helps.

 

Thanks - may give this a try but getting to the high end of my tinkering abilities now! I'm taking time out from this laptop cos it has frustrated me so much, will probably pick it up again in a few weeks.

Debbie