C860 Charging Problem (not Battery)

[bethanyb]

I have no idea what you guys are talking about. Someday I may learn about battery terminals and fuses. Hopefully not anytime soon.

My Zaurus C860 has been a brick for the past 4 months. I ordered a new battery, placed it in, charged it and nothing worked. Today I was thinking of how to get rid of my Zaurus. I came to the forum and was inspired by you all not to give up. It was easier than I thought. I reinserted the battery, plugged in the charger and voila! it came back to life. I am amazed and so happy to have it back. I'm hoping it just needed a new battery.

[dbowden]

Maslovsky -- Thank you!  That was excellent information.  I was nervous about taking my Z apart, but the actual surgery was sort of anti-climatic.  Everything went smoothly, all the parts went back together, and the Z is charging as I type.  My charging fuse was blown, but the main fuse was OK.

I don't know what I'm going to do with a Zaurus that actually charges batteries!

For anyone else reading this and hoping to fix their charging circuits: KOA Speer sent me 25 of each fuse (more than I asked for)  So... I have plenty of extra fuses for both the main and charging fuses (2A and 0.63A).  I'll be happy to give some out to anyone else who needs them.

Of course, now that my c760 is fixed, I'll probably be looking for a C1000 or better  

OK, guys, sorry for some long delay, but here are the pictures of the two fuses that need to be replaces in most cases to fix charging problem:

http://cacko.oesf.org/downloads/fuses/Main...use%20pic_1.jpg
http://cacko.oesf.org/downloads/fuses/Char...use%20pic_2.jpg

Pictures are huge, so I'm only posting links here.

And some explanaition form my friend:

Main protection fuse F804 (pic_1.jpg) protects the whole board from overvoltage.
Its nominal is 2 A. It gets burned in 95% of cases of overvoltage or wrong AC adapter polarity.

Charging chip fuse F813 (pic_2.jpg). ALWAYS BURNED. Nominal is 0.63 А

There are other fuses on the board, which may theoreticaly get burned but this has never happened yet.

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[maslovsky]

I'm glad it helped

Maslovsky -- Thank you!  That was excellent information.  I was nervous about taking my Z apart, but the actual surgery was sort of anti-climatic.  Everything went smoothly, all the parts went back together, and the Z is charging as I type.  My charging fuse was blown, but the main fuse was OK.

I don't know what I'm going to do with a Zaurus that actually charges batteries!

For anyone else reading this and hoping to fix their charging circuits: KOA Speer sent me 25 of each fuse (more than I asked for)  So... I have plenty of extra fuses for both the main and charging fuses (2A and 0.63A).  I'll be happy to give some out to anyone else who needs them.

Of course, now that my c760 is fixed, I'll probably be looking for a C1000 or better

[seva]

Thanks to everyone involved, in particular to maslovsky for the fuse information and dbowden for the information on where to find the fuses.  Had I been a bit more adventurous or a bit more experienced with this sort of thing, I could have figured it out much sooner, there are no more than 5-6 fuses total on the entire board, testing each would have taken well under an hour.

I requested samples and after a few weeks I assumed they are not coming in, contacted dbowden through private message and he has mailed me 3 of each fuse, on the same day his fuses came in the samples from KOA Speer came in (12 of each).

Taking apart the Zaurus was fairly easy, however, I don't have much experience in soldering, and while desoldering didn't take that long, actually soldering the tiny (1mm x 0.4 mm or so) fuse was pretty difficult for me (you will need a magnifying glass, I was using a small one from a "Swiss"-army knife).

First thing I did was test each fuse mentioned for continuity, which showed that only the 0.63A was bad, so I only needed to replace that.

Also, the "trick" I ended up using, this may be helpful to those who suck at soldering, is to cut a bit of solder with wire cutters and place them on the board, melt each piece of solder in place a bit, then place the fuse on top and melt each solder chunk while softly pushing the fuse down.

Thanks again everyone, I took a bunch of pictures if anyone needs additional reference, and If anyone needs fuses sent to them faster than 3 week via KOA Speer sample order, drop me a note.

This thread should be stickied and moved to the hardware section!

[edi800]

Also, the "trick" I ended up using, this may be helpful to those who suck at soldering, is to cut a bit of solder with wire cutters and place them on the board, melt each piece of solder in place a bit, then place the fuse on top and melt each solder chunk while softly pushing the fuse down.

I did something different, because I suck at soldering even more

I just left the original fuse in place, and glued (not soldered) the replacement fuse ON TOP OF IT. I used a generic Super Glue to do that.

After checking the connection, I found that it is faulty (so that just pushing one fuse on top of another does not result in a good electrical connection), so I added some silver conductive glue (this can be bought in a DYI store) to the ends of fuses.

This 'ghetto' fixing method proved very effective and easy. No soldering was needed, and I didn't even use a magnifying glass.

I'll try to post some pictures of it. In my case only the 0.63A fuse was broken.

Thanks Maslovsky for the pictures and the manual for finding the elements on the Zaurus's board.

[blaster123]

Those fuses are much smaller in real life then in those pictures...  I blew both the 2A main and the .63A charging.  I was wondering if I could get a few of those fuses from anyone that has them and would be willing to send, otherwise I'll have to make a sample order.  Edi800, could I see some pics of of the conductive glue repair.  I'm not the greatest solderer, and if it doesn't look too bad, that may be how I repair mine.  Thanks all in advance.

[seva]

Those fuses are much smaller in real life then in those pictures...  I blew both the 2A main and the .63A charging.  I was wondering if I could get a few of those fuses from anyone that has them and would be willing to send, otherwise I'll have to make a sample order.  Edi800, could I see some pics of of the conductive glue repair.  I'm not the greatest solderer, and if it doesn't look too bad, that may be how I repair mine.  Thanks all in advance.
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Private message me your shipping address.

[edi800]

Edi800, could I see some pics of of the conductive glue repair.  I'm not the greatest solderer, and if it doesn't look too bad, that may be how I repair mine.

OK, no problem, I'll post the pictures of my fixed setup and of the silver glue. I also thought, when I saw the fuses, that it is next to impossible to solder them
But glueing them on is really easy. :-)

[cgrieves]

If anyone finds's a retailer stocking these, please post here and I'll pay to buy a load of them, then we can send them out to whoever needs them. Likewise if I find a source I'll post it here.

Hi Cgrieves, I was wondering if you've managed to find the fuses - I'm in Woking and desperate to get my hands on them too... I can't for the life of me find anything on the Koa Speers / Littelfuse websites    Could you guys let me know where you got the fuses or perhaps post a direct link on where they are on those sites? Pretty pleeeaaaase .
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Hi Nataliya, sorry about the lack of reply, I haven't been here for a while!

Anyway I have tried reordering samples from both Littlefuse and Koa from their websites. I did all this before but never recieved confirmation, and nothing ever arrived. If I have any luck then I can easily send a few out to you- I've requested 25 of each fuse from each site. I'll let you know.

[edi800]

Finally I had some time to post the pictures of my 'ghetto' fix:

The best way to open the Zaurus is to use a credit card, pushing it along the edges
of the case.

Afterwards, you should remove a few screws to be able to rise the motherboard.

The 0.63A fuse is under the protective screen that can be seen on this picture:

Mainboard & Protective screen

This picture shows the new fuse already glued to the top of the old broken one:

New fuse on top of the broken one

This is the glue that I used to cover both ends of the fuses:

The silver glue

And this is how it looks just after applying the glue (with the help of a pin):
A little mess after applying the glue

This, as you can see, looks quite awful, but I was able to clean it and make it more professionally looking.

Unfortunately after straightening it out, I was so eager to test the charging of the battery (and it worked!) that I forgot to take the last picture, showing everything in a proper way.

But I hope that it still will be helpful to you :-)

Best regards,
Edi800

[phedders]

Hello - Just read this thread and others with anticipation... I've apparently blown the fuses in my 750 (

Is there anyone in the UK or near enough that has some spare and could send me a couple?

--
Cheers!

[seva]

To those who PMed me, fuses are in the mail, sorry for the delay.

Edit, Feb 21: Hey, I just mailed another set and I am out of 0.63A fuses (I want to keep a few spares for myself), so I suggest everyone request a bunch of samples from KOA Speer and post here if you are willing to ship them out to other Zaurus users.

[blaster123]

WOOT!!!  I'm back up and running.  I used a two part silver epoxy from the local hobby store and a large magnifying glass.  This time I'm going to be a little more careful what I plug into...  Thank you all for your help!

[edi800]

Allright! Way to go, man - I'm very happy that it worked for you too :-)

[cgrieves]

Well I've had no luck getting any samples from Koa or Littelfuse  

Koa never answer or anything, and Littelfuse always redirect me to Farnell or RS Components when I order samples, neither of which supply a .680 Amp fuse.

Anyway I gave up decided to buy some 0.5, 0.75 and 2 Amp 0603 fast acting fuses from Farnell. I'll see how I get on with the 0.75 Amp fuse first. I guess if it blows up and destroys the C860 then I won't really have lost much as it's sitting in a cupboard anyway!