I'm terrible with SMD components, and was hoping that someone could offer some advice.
I have an old 1st generation ipod which has started randomly rebooting. I've narrowed the problem down to the logic board. It will work fine for a while and then it acts up. It is almost like the caps are thermally sensitive.
Here is a picture of the board
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Does anyone see any suspect caps or other components to test / replace on this board? I don't see any electrolytics, but I don't know if they come in some other form than a can.
There are 'electrolytic' caps on that board in a format different from the cans you are expecting, although they are probably actually solid tantalums rather than traditional wet electrolytics. An example is the black block marked "C224" at the bottom left of the first picture, and the yellow "C114" at the bottom left of the second picture. Generally, I have found this type of cap to be pretty reliable in this type of application. Solid dielectric high value caps, don't suffer from the same physical problems as wet types.
If it is a genuine electronic problem, I fear that it is unlikely that you will ever get to the bottom of it, or if you do, be able to repair it. I used to do a lot of small SM stuff like this in the form of Sony personal minidisc players, and most of the intermittent problems came down to bad BGA LSI 's (or the soldering under them) or bad thru' plated holes, neither of which was realistically repairable in a 'traditional' workshop environment.
It might be worth just checking that there is no problem with the battery connections, the battery itself, or the charging / docking connector. Beyond that, unless you can find something really obvious, I think that the item is coming to the end of the line ...
Thanks Arfa... I had an assumption that a fix was far fetched since this is such a small piece of equipment. This one used to work great now it is intermittant, I have another ipod that the menut button doesn't work but is otherwise functional... The one with the non working menu button is very strange since if you shine an IR diode into the vias behind a large chip the menu button is activated. I discovererd this while inspecting the board under my desk lamp wich emmits a lot of IR. I glued an IR diode onto the board and wired it to the menu switch and it was an ok fix. It doesn't always work, but does most of the time. an intermittant menu button is better than none at all..
Too bad these boards are double sided, I'd try reflowing it in a toaster oven.
I think you are correct about the BGA joint. I found the unit works if I place pressure on one of the BGA chips.. I may try heating it up with a heat gun if I conclude that this is actully the chip causing the problem.
Well I managed to reflow that specific chip without any improvement.. So i moved on to reflow another and some superglue smoke got in my eyes and I pushed the bga chip off the board.. Oh well I didn't realistically think I would fix it anyhow. It was just an attempt.
Ok have you looked at the title of this group? It is sci.electronics.REPAIR Not sci.electronics.BuyAnother Plus I rellly like the 1st gen Ipods and they're kind of hard to get. Have you ever used one? The wheel actually spins.
Why don't you do something usefull instead of trying to make everyone angry.
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