Saltar al contenido principal

Modelo A1181: procesador Core 2 Duo de 1.83, 2, 2.1, 2.13, 2.16, 2.2 o 2.4 GHz

Preguntas 1195 Ver todo

Burned SMT on MacBook A1181 "logic board 820-1889-A? Burn like!&&*

Hi, everyone. I have an old White macbook A1181, when it connect to the charger, charger green light turn on, no fan, no nothing.

So I take out the mother board for a look, find that there are two chips burned, I think they are SMT. That things fall apart when I tried to remove them. later I put the charger on, nothing change. Same green light, no sign of turn on.

It has "157" on one of the burned SMT, an other one’s information had burned out completely. I find anther smt on the other side(the yellow one), which look like the same(maybe), I have google the words on it, nothing useful is founded.

Do anyone know the spec of the smt and what do they do? I hope to replace them and see would that fix the problem. The mother board is 820-1889-A.

I know this is an old computer, it might not worth a big effort to fix it, but I do not want it become e-waste without a try.

Thank you for reading this question. Good luck, stay heathy and stay happy.

Block Image

Block Image

Block Image

Block Image

Update (12/18/2021)

I have took some better pictures of the motherboard. All the marking should be readable, hope this might help. The red line are where the capacitors should be, I have removed them with a hot gun. Thank you.

Block Image

Block Image

Block Image

Update (12/19/2021)

After more investigation. I have found the Schematics of the 820-1889-A. From the words on the board I look around U7600, and found that there are 4 poly-cased capacitors around. So, I have measured the voltage of the feet of the 4 capacitors , the 2 black capacitors right below the U7600, give about a 12V and the burned two capacitors give around 3~4V. From the Schematics I suspect those might be the C7652 and C7692 (both 150uf 6.3v) as the voltage which received shound not exceed which they can handle. Those route of C7652 and C7692 seem coming form the SMC, that all I can tell. No Idea why they all burned out. I will orde the parts and see what will get. I have no high hope of geting the computer to work, but that is what I will try. Thank you for all of you helping out. I will update what happen after I have done the replacement.

After more investigation. I have found the Schematics of the 820-1889-A. From the words on the board I look around U7600, and found that there are 4 poly-cased capacitors around. So, I have measured the voltage of the feet of the 4 capacitors , the 2 black capacitors right below the U7600, give about a 12V and the burned two capacitors give around 3~4V. From the Schematics I suspect those might be the C7652 and C7692 (both 150uf 6.3v) as the voltage which received shound not exceed which they can handle. Those route of C7652 and C7692 seem coming form the SMC, that all I can tell. No Idea why they all burned out. I will orde the parts and see what will get. I have no high hope of geting the computer to work, but that is what I will try. Thank you for all of you helping out. I will update what happen after I have the done replacement.

Block Image

Block Image

Update (12/22/2021)

After the change of the burnt capacitor, I finally get the computer to work. I put an cloudready OS(chrome OS) on it, and now it is good to web browsing and watching some videos on youtube. I think I will find more use of it in the furture. Thank you for your help.

Block Image

Contestado! Ver respuesta Yo también tengo este problema

Es esta una buena pregunta?

Puntuación 4
3 comentarios

The burned SMD components are Kemet tantalum polymer capacitors.

- de

EDIT: Somehow overlooked the first pic which shows better that there do not seem to be capacitor labels on the silkscreen. I have suspicions based on the schematic which ones these are since most of the other ones in the circuit have other identifiers that would exclude them, like the component package/form factor or material, but I don't know that I want to guess without more certainty. --

Do those caps have a number next to them on the board? The pics are fab, and lots of other parts have labels, though the caps don't seem to, or they are obscured.

Based on the docs I have, they are both likely part of the 3.3V/5V power supply system, but there are a lot of caps in this system since that's most of what else is in this area, but I don't have a boardview for this model that I can use without some tweaking so if the silkscreen actually gives the part identifier that would be super helpful.

- de

There are no words at the side of the capacitors, there are words for other component on the board(see in the p3,4), like Q7620,Q7621. I have no idea of finding more information of them.

I have check the jump start on the board (They say shorting jump start can turn on the computer without the keyboard.) One of them is 0V to ground, and the other one is 3.3V to ground. When I short the jump start, the fan seem to twitch a little bit, like a fish on the dry land, but would not turn. Do not know what to do with this information, but someone might have an idea. ( The two burned capacitor have already removed with a heat gun, so I think that part should not be shorted.)

- de

Agregar un comentario

1 Respuesta

Solución Elegida

This is how I finally found out the info. of the burnt capacitors without the board view. This might actually need some luck to find out, as not all the board have the markings on them.

The replacement is kind of easy if the have the proper equipment and some practice. " Hot air gun"/"heat gun" will be the equipment you need if you want to perform the repair.

Thank you for all of you sharing the information generously, it really help a lot.

Update (12/19/2021) (same content in the Question)

After more investigation. I have found the Schematics of the 820-1889-A. From the words on the board I look around U7600, and found that there are 4 poly-cased capacitors around. So, I have measured the voltage of the feet of the 4 capacitors , the 2 black capacitors right below the U7600, give about a 12V and the burned two capacitors give around 3~4V. From the Schematics I suspect those might be the C7652 and C7692 (both 150uf 6.3v) as the voltage which received shound not exceed which they can handle. Those route of C7652 and C7692 seem coming form the SMC, that all I can tell. No Idea why they all burned out. I will orde the parts and see what will get. I have no high hope of geting the computer to work, but that is what I will try. Thank you for all of you helping out. I will update what happen after I have done the replacement.

After more investigation. I have found the Schematics of the 820-1889-A. From the words on the board I look around U7600, and found that there are 4 poly-cased capacitors around. So, I have measured the voltage of the feet of the 4 capacitors , the 2 black capacitors right below the U7600, give about a 12V and the burned two capacitors give around 3~4V. From the Schematics I suspect those might be the C7652 and C7692 (both 150uf 6.3v) as the voltage which received shound not exceed which they can handle. Those route of C7652 and C7692 seem coming form the SMC, that all I can tell. No Idea why they all burned out. I will orde the parts and see what will get. I have no high hope of geting the computer to work, but that is what I will try. Thank you for all of you helping out. I will update what happen after I have the done replacement.

Block Image

Block Image

Fue útil esta respuesta?

Puntuación 1
Agregar un comentario

Añadir tu respuesta

Ant Bee estará eternamente agradecido.
Ver Estadísticas:

Ultimas 24 horas: 0

Ultimos 7 días: 3

Ultimos 30 días: 4

Todo El Tiempo: 229