Fan Error T40 *PIC*

[Metallo]

Hi guys,

I got the fan error so the first thing I did, I changed the fan.
New fan, the laptop started again, I did some updates and used it as usual, I tried a restart: fan error again

Honestly, I don't know what the root cause can be, can you help me to discover it?
My configuration is in the signature below.

Thank you!
Alex

[ajkula66]

If the replacement fan is a *known working* unit, then the motherboard is at fault.

[Hans Gruber]

Pull the bios battery and do a hard reset. If you get a fan error after you have wiped the memory you may have another problem. My second suggestion is to get another fan. If you still get a fan error, ajkula66 is probably right.

[Metallo]

Hi folks,

I pulled the battery out and did a hard reset, no change.

I doubt the fan is defective as I saw it working fine for at least 3 -4 times when booting the PC.
Not sure if this is a coincidence, but before I got the new fan it took approx. 3 weeks, the first thing I did was to plug it in an and see if the PC would start, and it did.
After, I re-assembled everything and again it booted no problem.
Basically, 3 weeks ago I got the fan error, then after 3 weeks, new fan, it works for 3-4 time and then it stops again?

Last Jan, I replaced the F4 fuse, I wonder if a defective soldering would cause this issue ?? As you know, they are very tiny fuses and not easy to replace.

Also, the BIOS battery, I never replaced it in 12 years, I guess this has nothing to do with this, but in case...

Additional thoughts? I am far from thinking to a MB issue... at least not for the moment

Thank you
Alex

[dr_st]

Try another fan. Stuff happens.

[Metallo]

OK guys I just got another fan and tried to plug it in, it does not start.

One month ago I followed your previous suggestion and I did a CMOS hard reset, so now when I switch the T40 on I see the IBM Logo, nothing happens, then I press F12 and ESC, I see the diagnostics of the memory loading till 2GB, then quickly the rest and finally 'Fan error'

What do you think at this point?

As I measure the tension at the fan I get voltage, I still cannot understand why it started the first time I replaced the fan one month ago... this is a mystery to me.

Thank you
Alex

[RealBlackStuff]

Your old CMOS could still be re-used if it shows more than 3.0VDC
If not, replace that 12-year old CMOS battery with e.g. this: http://www.ebay.ca/itm/251578655412
You'll be forced into BIOS after the first boot, to set date/time.

[systemBuilder]

It's been a while since I opened one of my T42's so here are some thoughts.

I am thinking that the BIOS detects a fan-error in one of two possible ways:

1. They use a temperature measurement circuit inside the pentium cpu.
2. They might have a circuit that detects amperage going through the fan circuit (with a moving fan the resistance in the circuit will be higher and so the amperage will be lower).

If the detection works via (1), you might remove the keyboard and try cooling off the cpu with a blow dryer (no heat option) or in the freezer (fan error would take longer to occur) to see if you can get the laptop working. If it works, then perhaps your heat sink is failing (did you replace the fan and heatsink at the same time? Did you use thermal paste or at least toothpaste to get a good bonding between the CPU and heat sink?)

In any event, just because you replaced the fan doesn't mean it's not stuck getting started (which is the typical failure mode), so try starting the laptop with the keyboard loose so you can tilt it up and look for the fan spinning, a replacement fan might still be sticky and have trouble getting started.

If you replaced only the fan (and not the heat sink), you might want to add some electrical or duct tape around the edges to get an airtight seal so that the fan is more effective at drawing air through the heat sink pipes. Another (remote) possibility if you replaced only the fan is that the water or fluid in the heat sink pipes is somehow stuck or clogged, so it cannot move through the pipes via capillary action, ergo, make sure to replace the heatsink, too.

Also, check the fan to see if it's very dusty and blow air through it to clean it, big chunks of dust stuck to the fan can slow it down and possibly could trigger the error if the bios is using either of the techniques (1) or (2) above to detect a fan error. This might explain why it stopped working after 3 weeks.

Good luck!

[brchan]

A similar thing happened to an old T41 I had. However, the problem magically solved itself after replugging the battery. The laptop later died of the infamous ATI gpu issue.

[MrMaguire]

Southbridge issue, maybe? I doubt that all 3 fans are faulty, but with ThinkPad fans you never know.

[Metallo]

Hi and Happy New Year to you all!

I found the root cause of the fan error.
As I suspected, it is the F4 fuse which I soldered few months back, when I measured the voltage to the fan it was giving 2V instead of 5V.
I just touched the fuse and, in fact, it popped away from its location.
To confirm , I bridged the fuse and got the 5V and a working fan.

Now, a problem generated another, to solder that fuse is very difficult and, likely, due to too many attempts, the trace broke.

So I now have two problems:

1) Repair the trace
2) Solder the fuse again

I need help with both.

I removed the MB and took a picture so that you can see how good I am in making damages.
Please, zoom in so see it clearly.

http://www.mediafire.com/view/h9c862use ... G_6321.JPG

How do I fix this?

2) I want to solder the fuse using two wires, it won't be as effective but better than nothing, do you see a workaround to repair the trace and get the fuse in place at the same time?
I guess the wires to solder the fuse have to be very thin and very short, I was thinking half a inch long each, too long, too short??

Thank you for your help.

Alex

[rkawakami]

Give me an hour or so... I'm looking at your photo and investigating some possibilities.

It appears that you either used too much heat on the soldering iron and lifted the pad and trace off the board OR too much physical force was used to lift the fuse. You should either be using a temperature-controlled soldering iron (set somewhere around 225C for today's lead-free solder) or a simple iron of about 25 to 30 watts.

[rkawakami]

Okay, here's what I would suggest:

<-- Click on thumbnail for larger (635x475; 70KB image)

- Solder one end of the 0.5A fuse to the remaining pad on the motherboard (larger red square). I'm assuming for now that it is still firmly bonded to the board and that it can withstand a few more seconds of heat applied to it.
- Using a piece of wire, no smaller than 24 gauge, solder one end to either one of the pads highlighted with a blue circle. I'm not sure if 24 gauge wire will fit down inside the hole in the board (aka, via). If it does, great. Put about 1mm or so down the via and solder it. If whatever wire you use doesn't fit the via, then just solder the wire on top of the hole. You can use bare wire (i.e, not covered by any insulation) as long as you can guarantee that it does not touch any other component on the board. 24 gauge is the thinnest that can handle 0.5A of current.
- Run the other end of the wire to the fuse and solder there.

If it turns out that the remaining F4 pad is not usable, then you could try this:

- Glue the fuse to the motherboard slightly to the left of where it would normally go. In other words, cover the damaged via with the fuse. A bit of "superglue" should work, just give it enough time to bond to the board (an hour should be okay but read the directions on the glue).
- Solder a wire from one of the red pads/vias to the fuse. I'd use the red square as a first choice as that appears to already be covered with some solder.
- As above, solder another wire from one of the blue circles to the fuse.

Again, use as low as heat as possible to melt the solder and don't leave the iron touching the wire or fuse any more than 5 seconds as you apply the solder. Use the thinnest solder you can get your hands on. Something around 0.5mm or less is great (but somewhat on the costly side as you typically have to buy a large spool).

[RealBlackStuff]

And completely ignore ROHS by using solder comprising close to 60% tin/40% lead.

[Metallo]

Thank you Ray for the very detailed instructions.

Unfortunately, notwithstanding my solder is only 20w and I have the right tip, I was unable to solder the fuse.
And yes, I use 60% tin/40% lead as a tin.

The fuse I purchased some months ago is this one: http://ca.mouser.com/ProductDetail/Schu ... JuAw%3D%3D
I believe the connecting part on both sides of the fuse is gone now (too many attempts) and cannot use it anymore.
My degree of expertise with a solder is not top class, but I am not even a beginner given that I am 50+ and I have soldered many many times before, but this one is tough to make.

I need to buy a new fuse, is there any other type I could use? I mean, easier to solder?

The two blue contact points you indicated, although I scratched them to facilitate the soldering, they seem to be too small to allow the tin to bond.
Ideally, the wire should go through the hole, but I am not sure if it is smaller than 24 gauge (0.51 mm).

If only I could use another type of fuse that has wires as contact points...
However, the original broken contact part, looks like it can still be used because the tiny part left has tin in it.

Thank you for your advice.

Alex

[RealBlackStuff]

This one is a bit bigger: http://www.mouser.com/ProductDetail/Lit ... hJKSsmk%3d

[rkawakami]

About the only type of leaded fuse that I know of and can fit in the small area where F4 normally goes, is a "pico fuse". Browsing through Mouser.com, here are some possibilities:

http://www.mouser.com/Circuit-Protectio ... ma&FS=True

In particular, this one:

http://www.mouser.com/ProductDetail/Lit ... 52bu4y4%3d

Rated at 500mA, fast-blow, it's just a little bit double the size of the original fuse.

[RealBlackStuff]

Interesting finds!
Never even knew they existed, could have used those a few times...

[Metallo]

Hi,

I ordered the Pico but no way, this is too big and in addition, the blue round points, for whatever reason I cannot get the tin to bond to them.

I have now to re-ordered some fuses as the previous ones , which themselves are already bigger than the original one.
Hopefully I can find a thinner tip too.

This is a challenge indeed but I am stubborn, let's see...

Alex

[rkawakami]

Profuse apologies... I thought that the original fuse was about 3mm long but it looks like it's more like 1.5mm. The pico fuse is about 7mm long. If you can't solder to either blue circle then you may be able to solder the fuse to the end of the chip capacitor near the left-most blue circle. Same goes for the red areas; if you can't solder to those, then follow the trace up to the pin on the IC labelled "658". I hesitate to mention this option as it may lead to damage / shorting of those components if excessive heat or too much solder is applied .

[Metallo]

Hi,

I received the new fuse, it may not be the best solder to see but at least it is very firm.
Now, I have to reassemble everything and try



I will let you know if it is revived

Alex

[Metallo]

Hi,

My T40 it's up an running again, hopefully the solder will last longer this time.

Thank you all for your help, you have been fantastic!

Take care,
Alex

[Metallo]

Hi guys,

My T40 is still running very well, fan is working full power, however I noticed a change after I fixed the F4 fuse:

When I log out and click restart, I get a fan error and the system shuts down, however, shutting down and rebooting is never an issue.

This is not a big problem for me but I wonder what may trigger this behavior.

Many thanks,
Alex