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Power supply fan inactive/failure

post #1 of 13
6/17/03 at 4:13am
Thread Starter 
Having used my new Sager 8887 for a month, I never seen the cooling fan inside the external power supply operate. The unit get very hot and the fan should kick in long time ago. To observ the fan you will have to use a strong flash light and observe it through the opposite end to the power adapter socket.
My feeling is, from observing this forum, is that this is a manufacturing/design failure that is a common fault to this model.
Since I live in Europe, I would like to know if there is a fix for this problem, other than a replacement of the hole unit.....

Thanks!
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post #2 of 13
6/17/03 at 2:39pm
My fan has also never turned on. I have called them and asked personally and they tell me that the pws brick is working properly. I personally do not believe them. That thing has gotten soo hot that it is painful to touch. I am worried that it will melt (or burn a hole in the carpet).
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post #3 of 13
6/19/03 at 4:11am
Thread Starter 
Quote:
Originally posted by i_knowz
My fan has also never turned on. I have called them and asked personally and they tell me that the pws brick is working properly. I personally do not believe them. That thing has gotten soo hot that it is painful to touch. I am worried that it will melt (or burn a hole in the carpet).
Since my problem seem to be the same, I simply took the unit apart, and had a closer look at the internals. Doing some research I came up with a simple fix; requried some soldering and about 15 minutes time. Now the fan is running at full blast.
RESULT; after 2 hrs use the externals of the power supply is from cool on one end to about 40 degC at the other end. Ambient about 24degC or 74degF. If somone else want to know how to... drop me a line.
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post #4 of 13
6/20/03 at 12:18am
Quote:
Originally posted by BJsr
drop me a line.
LINNNNNE!! Drop your fix in here if you can, there are lots of solderers in the forums. Thanks.
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post #5 of 13
6/20/03 at 3:10am
About those "bricks" and their fans - exactly how loud is the fan inside the ps? Noticeable?
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post #6 of 13
6/20/03 at 9:48am
Thread Starter 
Quote:
Originally posted by MrMsyvc
LINNNNNE!! Drop your fix in here if you can, there are lots of solderers in the forums. Thanks.
Nice to know!
I would like to return with som pictures some time later, but for the not so faint of heart, here is the description;
Disconnect the external mains connection.
Remove the two rubber pads and locate the two screws.
Remove screws, open the box by gently squeesing the lower part while removing the top. The opposite end to the screws, act like hinges to the top lid, try gently to swing it loose without breaking the lugs. Once loose, locate the fan assy. Next you will find the two lands connected to the fan terminals. One of the terminal takes its ground from a surface mounted resistor. Cut the copper track between the resistor and fan terminal. To create a new ground reference, solder a connection to the ground lead going to the 20vDc output( the ground is running along the edge).
Finally verify no shorts, before reconnecting to mains. Once connected the fan will run at max power 5vDC, and 20vDc out will read about 19.9 volts. Once looking good, cover the broken track with laquer and reassemble the unit in reverse of described.
Good luck it should work. Next connect to computer and you will find this is remaining COOL!!!!
good luck!!!

Good luck!
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post #7 of 13
6/20/03 at 11:01am
"VERY COOOL!" Adam will usually post pictures for you if you don't have a web site. Thanks for adding to the Sager Encyclopedia!
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post #8 of 13
6/20/03 at 11:27am
Hmm,

I'll take mine apart this weekend and see why it doesn't turn on in the first place.

Here's how it's supposed to work:

A temperature sensor feeds a voltage reference into a circuit. Once the voltage gets above a certain point the circuit will turn on and depending on temperature (voltage) COULD then feed a varying voltage to the fan. Or it could just be set up to turn on/off only.

As the temperature goes down past the reference and past the point of hystersis (prevent the fan from oscillating on/off around the trip point) the fan will then turn off. What's happening here is the temp sensor never trips the circuit. This could be because the reference voltage is either too high or faulty assuming the temp sensor is putting out the proper voltage.

Are you sure you cut the ground line? Or maybe the fan is hooked up backwards to exhaust air instead of intake and you cut the power. Either way I'll take a look at mine and get out the VOM and do reverse engineering on it. Hopefully I can come with a solution that will allow the fan to turn on and off normally.

I checked the manufacturer's website and found no info. They have an office in California so I'm tempted to call and see if I get some info from them.
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post #9 of 13
6/20/03 at 11:52am
Thread Starter 
Quote:
Originally posted by beakmyn
Hmm,

I'll take mine apart this weekend and see why it doesn't turn on in the first place.


Are you sure you cut the ground line? Or maybe the fan is hooked up backwards to exhaust air instead of intake and you cut the power. Either way I'll take a look at mine and get out the VOM and do reverse engineering on it. Hopefully I can come with a solution that will allow the fan to turn on and off normally.

I checked the manufacturer's website and found no info. They have an office in California so I'm tempted to call and see if I get some info from them.
Hi again!
The 5volts fans are kind of special; the rpms change from 4 to 5 volts are not so great, so they tend to be switched on and off for speed control. Why the speed control? Noise? If you listen to this fan running at 5 volts, it is barely audible, so why all this fancy speed control?
The bottom line is it keeps the unit cool, and alive the way I have connected it. If the fan breaks it cost just a few bucks to replace.

Beeing a strong believer in KISS (keep it simple stupid) I do hope this little input can take away the headace for some of you getting the All Right from Support!!!!
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post #10 of 13
6/20/03 at 8:50pm
Ok I took it apart but there's no resistor. All I see is a smd capacitor. I haven't put the VOM on it yet or tried to trace it out. The power supply appears to pretty decently designed and filtered for noise suppresion, copper shielding, conductive tape, etc. Plus I like the 'condoms' on the mosfets and voltage regulators. I haven't seen those before.

I don't have digiatl camera so any pics you post would be helpful. I'm going to try and contact the CA rep.
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post #11 of 13
6/22/03 at 5:29pm
I actually got sent a replacement pwr supply from sager because the fan didn't work in it. The one the sent me turns on once and a while. I banged it yesterday after reading the posts and now it works all the time. So are they cheaply soldered? I don't think us the users should be left dealing with this problem!
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post #12 of 13
6/23/03 at 1:20pm

Strange...

I have two power supplies (one acts as a "docking station" at home).

They're not exactly the same... The fan on the first one is always on (I bring it with me all the time). The the fan on the other one starts when there is a high-power demand (games, etc ...) and stops when it's just "charging". I've never had a problem with the temp on either.
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post #13 of 13
6/24/03 at 8:42am

The Offficial Word from EDACPower

From the manufacturer:

Quote:
Dear Sir,

The fan only operates when the power load exceeds 90W.

If the fan does not turn on, it means the power supply has not exceeded the
temperature rating for it to turn on.


-----Original Message-----
From: joe [mailto:joe@edacpower.com]
Sent: Monday, June 23, 2003 2:46 PM
To: jasonyang@edacpower.com
Subject: [Fwd: Question on Power supply model EA11203]
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