Power supply iMac A1311 help

[patrik1998]

"Hi help I need to fix an iMac with the same PS board, damaged by a lightning strike. When I opened it, the board wasn't working at all: I replaced two burned SMD resistors and two capacitors, and the iMac came back to life. But after a short time it became to shut down and restart by itself... I guess I misread the value of some burned component, replacing it with the wrong one(s). Can you please . me? They are R003, R004, C009 and C010. Many thanks in advance!"

[Retro-Hipster]

Re: Power supply iMac A1311 help

Hmm.. I tried to find a schematic on the PSU but couldn't really. Have you looked to see what chips are in use on the PSU and tried to get schematics based on that? Knowing apple they might be relabeled in some way to keep people from repairing stuff. ^^; But in leu of a schematic I would probably take a look to see if you can find any datasheet on the switchmode chip and, if it is one close to the chip, you may be able to find the recommended value of the resistors. A lot of switchmode chips have really full schematics or details on their operation.

The other option could be looking on eBay for a board. From what I am seeing there are many used boards for around 15-20$. That is pretty decent considering how beefy the power supply actually is for its form factor. You could, for instance, buy one as a replacement for your mac book, figure out what part values you need for the other, then use one of the two PSU's for a project later. You might even be able to just ask one of the sellers if they could send you an HQ picture of the board.

From what I can gather, the board for your A1311 is either a 614-0445 or 661-5299 board. I could be wrong on that though.. Maybe someone else would be more able to help you.

[Bowayne]

Re: Power supply iMac A1311 help

Im also looking for a schematic for 614-0445 mac psu

[pcardoso73]

Re: Power supply iMac A1311 help

Im also looking for a schematic for 614-0445 mac psu

Me too.
It is really difficult to get them.