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Throbin
Aug 17, 2009, 02:42 PM
Hi all, new to the forums (and Mac, as well!)

I just got a first generation G5 iMac dirt cheap, and it has the infamous popping capacitors problem. No big problem, I've got friends who can handle this. I get them a kit of caps and they solder them in for me (and get a case of beer - but I digress).

However, while scanning the logic board for other problems, they came across two apparently missing resistors; namely R3316 and R3313. I have arrowed the resistors in the attached .jpg. Also missing is C3470 (obviously missing at the top right hand corner of R3317). Does anyone know which resistors I should get for R3316 and R3313, and which capacitor for C3470?

Any advice welcome!

Cheers,
Robin



MTI
Aug 17, 2009, 03:12 PM
Don't sweat it. All Apple logic boards have unused component locations screened on them. I'll be you'll even find some unused cap locations.

Unless there's signs of removal (scratches, heat marks, uneven solder pads) of a component, it's just an used spot.

belvdr
Aug 17, 2009, 03:15 PM
MTI, take a look at that photo. It isn't just unused components.

OP, have you google for schematics for that model?

zmttoxics
Aug 17, 2009, 03:15 PM
They aren't missing, per say. Often in computers, there are junctions left open for use between models to set different settings (speed, locks, who knows). Yours just happens to not need those set. :)

rtrt
Aug 17, 2009, 04:42 PM
agree with belvdr - click on the larger version - someone has modified that board post purchase.

I wouldn't be surprised if that machine was toast - but then if you have access to friends who can work on logic boards - maybe you'll be fine

MTI
Aug 17, 2009, 04:55 PM
Okay, I took a look at the larger image and 1) the soldering is extremely sloppy on those surface mount resistors and one is missing, given the burn marks.

Throbin
Aug 18, 2009, 01:10 AM
Okay, I took a look at the larger image and 1) the soldering is extremely sloppy on those surface mount resistors and one is missing, given the burn marks.

Thanks for all the replies, people!

The sloppy soldering is what roused our suspicion in the first place. We think some hack tried to replace the caps (some are replaced) but he just gave up. Not a very bad decision, considering his soldering skills :D

I've Googled until my face was as blue and white as my G3, but I don't seem able to find a schematic anywhere. Any pointers to a schematic online somewhere?