T500 fan error - fan socket doesn't provide power

[v0yAgEr]

Hi everyone,
Im trying to repair an old T500 that displays the famous "fan error" message on stsrtup.
I got a replacement fan online, but the fan won't start.
I measured the fan socket with a multimeter and the voltage was basically 0.
I read a bit here and on other forums and I suspect that the fan fuse just blown up. The problem is that I couldn't find any page or document that describes the T500 fuses.
Anyone knows what is the right fuse and where is it on the board?
Moreover, how can I test the new fan without the board? 5v power supply didn't make it spin...
Thanks,
v0yAgEr.

[RealBlackStuff]

I removed the fan-socket from a faulty T60 motherboard, and connected it (with a potentiometer in-between) to a USB-plug.
That way I can test ca. 98% of all fans, using any USB-port anywhere.

If yours does not 'run' that way, it's a dud.

The fan-socket has a 2.0A fuse named F4, it should be very close by.
It measures only 1.6 x 0.8mm and will have the letter N marked on it.
The fuse-color will most likely be green or brown.
To replace it look for Panasonic ERBSE2R00U.
Have fun finding it and soldering it 'piggyback' style, on top of the old one.

[v0yAgEr]

Hi,
Thanks for the quick reply!
I will search for the fuse soon, but I also want to verify that we are on the same page: my laptop is T500. Does it have the same fuse F4 as the t60 you mentioned?
Thanks again!
v0yaAgEr.

[RealBlackStuff]

I only used the word "T60" in my description of how I made a test-connector.

The F4 fuse is the real deal on a T500 mobo.
And as it happens: on a T60 mobo the fan-fuse is also named F4, is also 2.0A, but the fuse used there is a Littelfuse 434002.
Those fuses are interchangeable.

[v0yAgEr]

Sorry for not paying attention
It will take me a while to get a hold on the replacement part and to perform the repair itself (and I need to verify that the fuse is indeed the culprit).
I'll keep you posted.
Thanks again!

[v0yAgEr]

I had taken the time to remove the board, and tested the F4 fuse. It is indeed shorted blown.
I started looking online for the 2 suggested fuses, and immediately found them on mouser.
The problem is that they are too old and out of stock. Instead, I can get them from AliExpress for 9$ shipped to Israel.
The problem is that the shipping time is probably going to be a bit long, and that sucks.

I once managed to get parts from mouser in Israel without the shipping fee, and I want to try and do that again.
Of course I need parts that are in stock. So, I tried to find some newer fuses with similar specs at mouser.com.
I managed to find some, and wanted to consult about specific one that I want to try and achieve.

The fuse is Littelfuse 0467002.NRHF, and this is the mouser URL: http://il.mouser.com/ProductDetail/Litt ... %2f6AKw%3d
What do you think? Will this fuse be able to successfully replace the old one?

Thanks again!
v0yAgEr.

[rkawakami]

Before we get to the question of compatibility of the fuses, a clarification is needed... When you say that the fuse is "shorted", exactly what resistance value did you read? "Shorted" implies that you measured 0 ohms across the ends of the fuse, which is actually what a GOOD fuse will measure (i.e., one that has not yet blown and would pass current through it). If you measured significantly more than 0 ohms, then the fuse is "open" and has given its life to (possibly) protect other silicon lifeforms on the motherboard. Note that even if you have a bad fuse and replace it with a good one, the new one could also go up in smoke if the cause of the excessive current has not been corrected.

Here's the match-up for the specs that really matter:

Spec              Littelfuse 434002     Littelfuse 0467002.NRHF
Current Rating:          2A                       2A
Voltage Rating:         32V                      32V
Fuse type:           Fast Blow                Fast Blow
Fuse size/group:     0603 (1608)              0603 (1608)

In short, yes that 0467002 will work.

edit: And here's the answer from Littelfuse itself: http://www.littelfuse.com/products/fuse ... 34002.aspx

"Series: 434 Obsolete: 2008-12-31 Replaced By: 0467002"

[v0yAgEr]

I should not write when tired, especially in non-native language.
The fuse is indeed blown, not shorted. Very silly mistake by me - sorry for that

I measured the fuse using the continuity mode of the multimeter. It didn't beep. If I'm not mistaken that means that the fuse is dead. Other fuses on the board beeped right away, so that's another reinforcement the test was done properly.

BTW, I tested the new fan again, but this time took the time to connect the wires in a proper manner. It worked this time with no issue!

The conclusion is that the board is the culprit, and not the fan. Now, as you said, I hope that it's just the fuse and nothing more.

Many thanks for the help, much appreciated!

[axur-delmeria]

Did you test if the old fan is still working?

IMO I can't think of a reason why the fuse would blow, except the fan shorting out. ~_~

[v0yAgEr]

I tested the old fan and it works, but far from good. It spins at half the speed and makes noise. I wouldn't be surprised if it caused the fuse to blow. It's worth mentioning that at the beginning of the fan error issue, the fan was still spinning and cleaning it was the first thing I tried. It helped for a short while but then it stopped working completely. I can only.assume that the problematic fan just drew to much current and blew the fuse.

[v0yAgEr]

Managed to order Littelfuse 0467002.NRHF as a sample from mouser. Should arrive in a week from today.
Will keep you posted how the repair is coming along

[RealBlackStuff]

Make sure your laptop remains without power (battery and charger) until you are finished with the repair.
Before you start soldering, with all power, RAM, HD and CD removed, press and hold down the Power button for about 15-20 seconds to discharge any capacitors that might still have a load.
One sample fuse does not allow you to goof with the repair.

[v0yAgEr]

Thanks for the advice!
Actually, the laptop is now almost fully disassembled because the fuse is at the lower side of the board. The inspection and testing of the fuse gave me no other option but to take almost everything apart.
I have no intention of reassemble anything prior to the soldering of the new fuse, as the laptop is not usable anyway with the current fuse.
I assume the electronics will get discharged enough while I wait for the replacement fuse this week, right? Or should I just connect the keyboard cable and press the button anyway just to make sure?

[v0yAgEr]

I'm glad to inform that IT WORKED!
The laptop is running cool n' quiet with the new fan happily spinning inside

In more detail,
I managed to pick up the fuses from mouser warehouse today (I ordered 3 just in case I'll lose one or ruin them).
I have decided to try and remove the old fuse before soldering the new one. I know, I know. It was risky and dumb, but I decided to do that for the fun and for the challenge (I guess).
In order to avoid heating and accidentally desoldering other gentle parts in the area, I used heat resistant tape and covered everything but the fuse itself.
At the beginning I tried to desolder the fuse using the iron. It was a no go - just too hard.
Then I decided to use the hot air gun that is part of my station (definitely should have done so in the first place - it's the obvious tool for the task).
My technique was to blow 315c air on the fuse at the lowest airflow possible, and in the meanwhile slightly push the fuse using long and sharp needle. When it was hot enough, the fuse just moved away and I was able to easily remove it.
After the removal, I cleaned the board using alcohol, and used the iron to apply a tiny bit of fresh solder to the joints of the fuse.
Using the hot air gun again, I soldered the new fuse into place. I wasn't sure if it attached firmly enough, so I did some final touches using the iron. I cleaned the area once again and after quick eye inspection the joint appeared to be OK.

I then reassembled everything and powered on the laptop. What can I say, it worked very well.

After getting this done, my tips are:
1. Hot air gun is very useful to remove the old fuse. If you don't have one, don't try to remove it. Really, just don't. "Piggybacking" is the way to go in that case.
2. Using a small iron tip is recommended, preferably one that has a 45 degrees cut so it would be easier to apply solder to the joint\the edges of the fuse.
3. The tape was very important to keep the other components safe during the process.
4. The obvious - use solder flux, don't exaggerate with the temps, be steady and delicate, be patient. Be ready to lose the computer if something goes wrong.

Thanks again everyone for your kind help! I actually enjoyed performing this repair, and I hope people will find my explanation useful (I know T500 is an oldie - I don't have high expectations )

Peace!

[RealBlackStuff]

Good to hear!

What does that hot air gun look like?
And what size was the used 'opening'?
I was using this rather crude looking paint stripper to remove the SATA chip from T43 motherboards.
However, those chips measure ca. 9x9mm.

[v0yAgEr]

I'm using Yihua 995d rework station: http://www.yihua-gz.com/Products_detail ... sortid=271
This time I used the smallest nozzle for the hot air gun.

I'm not a pro or anything so I know some would raise an eyebrow about me owning such a unit, but I got it 2 years ago for 150$ shipped and I like it very much. I'm using it for all kinds of small repairs of equipment that I encounter (my family provides tons of work ) and its extremely useful.

I did a small research before purchasing the unit. I found out that there are many "manufacturers" of soldering equipment, but most of them are just pure crap. Then I discovered that Yihua is one of the best, and very recommended. Actually, some other manufacturers even counterfeit their products. I wanted something good, so I got one of their pricier models. But actually, Yihua has a great range of products to choose from at competitive prices. I ordered the unit directly from their website and payed them via paypal. The unit arrived very quickly by DHL.
Overall highly recommended.