Logic board schematics and testing procedures needed

I've inherited a "fried" imac from a friend. The machine was reportedly hit by a power surge from lightning although a surge protector was used. The machine will not power on, no boot chime, etc. I have reset SMC and the fans kick on in high speed but machine will not boot. I took apart the machine and inspected the logic board for burns, etc. and could find nothing. Replaced the RAM; nothing. Power supply tests out fine and I even replaced with a new unit; no change. On the logic board, I get LED#1 when the machine is plugged in, but when switched on, no other lights ever light up. I can get the fans to come on at high speed, the hdd and cd drives sound like they're getting power. My question is; I see all of these logic board repair services out there, what are they normally fixing and where are they getting their schematics etc from? This is not my everyday computer so it's kind of a hobby project at this point. Ultimately, if I cant fix it, I will probably have a pro get it going, but I would like to give it a shot.

Contesta esta pregunta Yo también tengo este problema

Es esta una buena pregunta?

Calificación 2

Comentarios:

To any of you following along, schematics are available here:

http://www.laptop-schematics.com/

Cost is approx. $30 per machine.

por

seems a shame to buy the schematics and have taken the mac apart just to give it to someone else to fix... give it a shot. we all start somewhere and mayer is a very clever/helpful man!

por

Well thank you Polly. You got me to blush

por

I'd spend some money on trying to get the valid schematic for your computer. Since you described it to be hobby, what better way than to get the Mac revived with the help of the experts on here and to follow their advise. mayer is always a great source of experience and knowledge. Good Luck.

por

ABCellars, why would you vote to remove this as spam/offensive? Am I missing something?

por

Mostrar 5 comentarios más

Agregar un comentario

2 Respuestas

Respuesta Más Útil

Check the LEDs after changing the power supply and let us know.

Fue útil esta respuesta?

Calificación 2

Comentarios:

In the initial description it was stated the power supply had been changed,

por

Agregar un comentario

Did you examine the capacitors on the logic board to make sure none of them are busted? Look for swollen or bent caps. Thats about all the advice I can add

Fue útil esta respuesta?

Calificación 1

Comentarios:

This is not one of the G5 iMacs that had the bad caps problem, but it couldn't hurt to look.

por

Agregar un comentario

Añadir tu respuesta

info251 estará eternamente agradecido.
Ver Estadísticas:

Ultimas 24 Horas: 2

Últimos 7 Días: 12

Últimos 30 Días: 72

Todo El Tiempo: 3,967