Help with SMD Components

[Michael Kennedy]

Hi everyone,

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
http://onetechcomputers.com/ipod1.JPG
http://onetechcomptuers.com/ipod2.JPG

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.

TIA.

Mike

 

[Michael Kennedy]

Oops.. typo in the second URL

it should be

http://onetechcomputers.com/ipod2.JPG

 

[Arfa Daily]

Oops.. typo in the second URL

it should be

http://onetechcomputers.com/ipod2.JPG

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 ...

Arfa

 

[Michael Kennedy]

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 ...

Arfa

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.

Mike

 

[Michael Kennedy]

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 ...

Arfa

Arfa,

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.

 

[Michael Kennedy]

Arfa,

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.

Mike

 

[Lynn]

Hi everyone,

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 boardhttp://onetechcomputers.com/ipod1.JPGhttp://onetechcomptuers.com/ipod2.JPG

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.

TIA.

Mike

why don't you just buy a new ipod, moron?

 

[Michael Kennedy]

why don't you just buy a new ipod, moron?

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.

Mike

 

[Dave]

why don't you just buy a new ipod, moron?

It must be the adolescent in me but it's good to have you back if just for
the pure entertainment value of your posts.

You should lay off the abuse threats, they're obvious bullshit, ya' cock
hungry slut.