MacBook 13" charger circuit

  • Thread starter Jack B. Pollack
  • Start date
J

Jack B. Pollack

Guest
I have a MacBook 13" (not under warranty). When the charger is connected it
does not light or charge the battery. I have tested the battery and charger
on another MacBook and they are fine. I have reset PRAM and SMC. Cleaned
both the charger contacts and the ones on the computer.

Occasionally if I leave the charger connected to the computer for several
minutes I get a faint flickering light (I cant even really tell if the light
is green or orange or sort of both colors combined)

I am reading dual voltages at random spots in the laptop with the AC charger
connected.

My guess is that something has burnt out on the main logic board. I have the
computer open and have found one fuse (F 790) that is in tact.

Can someone with a service manual give me some test points and possible
components (voltages, etc) to check.

Thanks
 
<zwsdotcom@gmail.com> wrote in message
news:06519e97-56a5-480a-8246-0de93d515f6b@n19g2000vba.googlegroups.com...
On Jun 4, 8:22 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

Can someone with a service manual give me some test points and possible
components (voltages, etc) to check.
Click to expand...
I strongly doubt there is one - Apple services these machines at the
subassembly level. Suggest you do a comparative, since you have a
second machine available.

Also, I have encountered odd charging issues where the machine was
otherwise working OK when the MagSafe contacts were dirty. Make sure
you clean those too!


Thanks for your post.

The other machine is not mine so I can't really disassemble it.
Just tried re-cleaning the contacts, didn't help.
 
On Jun 4, 8:22 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

Can someone with a service manual give me some test points and possible
components (voltages, etc) to check.
Click to expand...
I strongly doubt there is one - Apple services these machines at the
subassembly level. Suggest you do a comparative, since you have a
second machine available.

Also, I have encountered odd charging issues where the machine was
otherwise working OK when the MagSafe contacts were dirty. Make sure
you clean those too!
 
Jack B. Pollack wrote:

zwsdotcom@gmail.com> wrote in message

news:06519e97-56a5-480a-8246-0de93d515f6b@n19g2000vba.googlegroups.com...
On Jun 4, 8:22 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

Can someone with a service manual give me some test points and
possible components (voltages, etc) to check.

I strongly doubt there is one - Apple services these machines at the
subassembly level. Suggest you do a comparative, since you have a
second machine available.

Also, I have encountered odd charging issues where the machine was
otherwise working OK when the MagSafe contacts were dirty. Make sure
you clean those too!


Thanks for your post.

The other machine is not mine so I can't really disassemble it.
Just tried re-cleaning the contacts, didn't help.
Click to expand...
Sometimes removing the battery and powering up from the charger works to
reset something. I haven't a clue why but its worked a couple of times
for me on a Dell and a HP machine. HTH.

--
Best Regards:
Baron.
 
"Baron" <baron.nospam@linuxmaniac.nospam.net> wrote in message
news:h099p6$i47$1@news.eternal-september.org...
Jack B. Pollack wrote:


zwsdotcom@gmail.com> wrote in message

news:06519e97-56a5-480a-8246-0de93d515f6b@n19g2000vba.googlegroups.com...
On Jun 4, 8:22 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

Can someone with a service manual give me some test points and
possible components (voltages, etc) to check.

I strongly doubt there is one - Apple services these machines at the
subassembly level. Suggest you do a comparative, since you have a
second machine available.

Also, I have encountered odd charging issues where the machine was
otherwise working OK when the MagSafe contacts were dirty. Make sure
you clean those too!


Thanks for your post.

The other machine is not mine so I can't really disassemble it.
Just tried re-cleaning the contacts, didn't help.

Sometimes removing the battery and powering up from the charger works to
reset something. I haven't a clue why but its worked a couple of times
for me on a Dell and a HP machine. HTH.

--
Best Regards:
Baron.
Click to expand...
Thanks. didn't help
 
Jack B. Pollack Inscribed thus:

"Baron" <baron.nospam@linuxmaniac.nospam.net> wrote in message
news:h099p6$i47$1@news.eternal-september.org...
Jack B. Pollack wrote:


zwsdotcom@gmail.com> wrote in message


news:06519e97-56a5-480a-8246-0de93d515f6b@n19g2000vba.googlegroups.com...
On Jun 4, 8:22 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

Can someone with a service manual give me some test points and
possible components (voltages, etc) to check.

I strongly doubt there is one - Apple services these machines at the
subassembly level. Suggest you do a comparative, since you have a
second machine available.

Also, I have encountered odd charging issues where the machine was
otherwise working OK when the MagSafe contacts were dirty. Make sure
you clean those too!


Thanks for your post.

The other machine is not mine so I can't really disassemble it.
Just tried re-cleaning the contacts, didn't help.

Sometimes removing the battery and powering up from the charger works
to reset something. I haven't a clue why but its worked a couple of
times for me on a Dell and a HP machine. HTH.

--
Best Regards:
Baron.

Thanks. didn't help
Click to expand...
Sorry about that !
Just a guess... Could there be a magnetically operated switch behind the
connector.

--
Best Regards:
Baron.
 
On Jun 4, 11:19 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

The other machine is not mine so I can't really disassemble it.
Just tried re-cleaning the contacts, didn't help.
Click to expand...
I assume you've been over the board with a fine-tooth comb looking for
possible dry solder joints or cracked copper, particularly in the
vicinity of the battery connector and charger input?

With the battery connected, what happens to Vbat when you connect the
charger - does it jump up (might take a couple of seconds) or does it
suddenly go to a sawtooth waveform, or what?

What happens on the other lines to the battery - do you see a
bidirectional I2C transaction taking place?
 
<zwsdotcom@gmail.com> wrote in message
news:0a6f92d1-b7ff-4740-b9f7-b13a5ea28d86@s21g2000vbb.googlegroups.com...
On Jun 4, 11:19 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

The other machine is not mine so I can't really disassemble it.
Just tried re-cleaning the contacts, didn't help.
Click to expand...
I assume you've been over the board with a fine-tooth comb looking for
possible dry solder joints or cracked copper, particularly in the
vicinity of the battery connector and charger input?

With the battery connected, what happens to Vbat when you connect the
charger - does it jump up (might take a couple of seconds) or does it
suddenly go to a sawtooth waveform, or what?

What happens on the other lines to the battery - do you see a
bidirectional I2C transaction taking place?


I check this stuff over the weekend.

do you see a bidirectional I2C transaction taking place?
I dont under stand this??
Click to expand...

Thanks
 
On Jun 5, 11:00 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

do you see a bidirectional I2C transaction taking place?

I dont under stand this??
Click to expand...
Well, step 1 - do you have a storage scope?

The battery has an onboard charge controller/gas gauge. The
communications protocol is I2C(ish).
 
<zwsdotcom@gmail.com> wrote in message
news:6c36e695-5738-4b0a-a457-501d210f3247@j20g2000vbp.googlegroups.com...
On Jun 5, 11:00 am, "Jack B. Pollack" <N...@NE.nothing> wrote:

do you see a bidirectional I2C transaction taking place?

I dont under stand this??
Click to expand...
Well, step 1 - do you have a storage scope?

The battery has an onboard charge controller/gas gauge. The
communications protocol is I2C(ish).

No scope.
I see 9V on one of the battery terminals when the charger is connected
(battery does not charge and computer doesn't work on AC). I Dont know if
there should be voltage on any of the other 5 contacts.

I was able to get my hands on a working mag-safe DC in board over the
weekend and swapped it into my system. It didnt help. So I know the problem
is definitely on the main board (I also know that the charger is working on
another system).

Any other thoughts on what components I could look at?
 
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