Anyone care to pick apart my parts list for a 17" iMac G5 recap?

[jkoravos]

Logic Board
20 - Nichicon HM 1800uF, 6.3V
5 - Nichicon HM 1000uF, 16V

PSU
1 - Nichicon HN 4700uF, 10V (Original is 6.3V, also this is 12.5mm vs. for the original, will it fit?)
2 - Nichicon HM 2200uF, 10V
3 - Nichicon HM 1000uF, 6.3V
1 - Nichicon HM 1200uF, 16V
1 - Nichicon HD 1000uF, 35V
1 - Nichicon PM 330uF, 35V

Any problems with the HD and PM in the PSU?

Any input would be appreciated...

-JK

[deckart]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

I use Panasonic for the LB and same as you for the PSU,just make sure they are all the same diameter and height in the LB as the rows either side of the CPU is a bit tight,ie 10mm max.The 4700/10v will fit,replace this one first,then do the others.Have fun getting all the glup off!.

[Toasty]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

>>1 - Nichicon HN 4700uF, 10V (Original is 6.3V, also this is 12.5mm vs. for the original, will it fit?)<<
Which make & model PSU do you have?

Midplane:
Should be 24 - 1800@6.3
Plus, I think you can get another 1000@16 in that 5 group. Test for voltage on open cap spots. Mix and match of solid polymers and reqular low ESR electrolytics. Gives sufficient capacitance and screamingly low ESR.

Toast

Get all the little caps in PSU too. Many set freq. of switcher circuit(s).

[deckart]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

These are the ones that need to be 10mm!,also Toasty I'd love to try out Poly's on my test Imac,where and which would you replace?.Be fantastic to be able to offer a super reliable Imac for a change.

[jkoravos]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

>>1 - Nichicon HN 4700uF, 10V (Original is 6.3V, also this is 12.5mm vs. for the original, will it fit?)<<
Which make & model PSU do you have?

Midplane:
Should be 24 - 1800@6.3
Plus, I think you can get another 1000@16 in that 5 group. Test for voltage on open cap spots. Mix and match of solid polymers and reqular low ESR electrolytics. Gives sufficient capacitance and screamingly low ESR.

Toast

Get all the little caps in PSU too. Many set freq. of switcher circuit(s).

I don't know the make and model of the PSU (see picture below). How can I tell? It's Model "B" on Jim Warholic's site. The Mac is the 17" first gen, 1.8 GHz. I don't see 24 of the 1800s, I think that may be for the 20"? I don't know. Mine looks just like the pic that deckart posted. A bank of 14 in the center, 2 at the top, 2 on the bottom right and 2 in the bank of 7 to the left, with the remaining 5 in that bank being the 1000uF,16V. There are a few empty cap spots on the board, though. Are those where the extra 4 would go?

Background: I got the machine from my uncle (through my brother). I know nothing except that he said it 'stopped working'. When I power up, I get the apple logo and working clock, then blank screen. Sometimes the fan spins up to 'ludicrous speed' after it's been sitting at the blank screen for a while. I get LEDs 1, 2 and 3 to light on power up. If I start in safe mode, I can get it to boot 'normally' and it seems to run fine. (Disclaimer: This is my first time ever using a Mac, so I don't really know what 'normal' is).

All the LB caps currently on the board are Nichicon HM with date codes H04XX. The PSU caps are mix and match. I have one exploded cap on the board (one in the bank of 2 at the bottom right, C909) and one in the PSU, the 4700/6.3V (B in the diagram below).

All the ones in my list are the same diameter (and height for the most part) as the original board. The only one I couldn't find a diameter match for was the 4700uF in the PSU. It's 10x30 on the board, but the the one on my list is 12.5x25. Nichicon does have a 10x20 4700uF/5.5V in their JB series, I wouldn't want to drop the voltage, though. The picture below looks like my PSU:



When you say, 'replace the smaller ones', I assume you're referring to J, K, L and M in the diagram above (my list contains A through I). Correct?

From the pictures I've seen, B seems to be the most common exploder. I think that the height, and clearance between the top of the cap and cover (which is virtually zero) leads to a heat transfer issue and more common overheating. It's probably a good idea to replace that one with something less than 30mm in any case.

[deckart]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

Hi,look on the back of the PSU,there is a sticker with an Apple part number,should be one of these:http://www.applemacparts.co.uk/store...ducts_id=57909
Before recapping,if possible and you have the original discs,put disc1 of the software restore discs in,reboot holding down the option key(alt) before it chimes and run the extended hardware test.If it comes up with any VRAM error messages the Nvidia card will also need reballing.You can usually tell this is necessary if you have a screen full of vertical lines with distortion.
I've just fixed a couple and they are not that tricky!,
Good luck.

[jkoravos]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

I don't have anything except the machine, keyboard and mouse. I can boot in safe mode and use it as normal. No video issues. When I do a standard boot, it doesn't get past the logo and spinner.

[deckart]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

That's good!.It's now up to you to replace ALL the caps.After that let me /us know of any problems.Be a good idea to see if you can get hold of an OSX disc to run Disk Utility after or just read this:http://support.apple.com/kb/TS1417,
Good luck!.

[jkoravos]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

I kind of wonder if it's a software problem, or both. The fact that it seems to run perfectly fine in safe mode makes me wonder. Obviously, it still needs to be recapped, since the caps are failing and the serial number is in the known batch of bad boards/psus.

I doubt this machine has the original discs since it came from liquidation sale, and you just get what you get. Is there somewhere I can get the required OSX disc to run the Disc Utility?

[deckart]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

Just buy any retail disc off Ebay,not Snow Leopard though,that's Intel only.The restore discs(2 of them) are machine specific but they do contain all the Iapps and AHT.

[jkoravos]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

Well, I'm posting from the iMac right now. Clearly it's functioning, but still not 'fixed'. I got the caps for recapping, but I haven't done anything yet. Apparently my uncle has the software for this machine, so I'm going to wait until I get it before I go any further.

I'm not sure what is disabled in the Safe Boot mode with this, but everything seems to be functioning. There is definitely some video issues going on. There's a weird pixelation pattern. Possibly a bad cap artifact, I suppose.

[weirdlookinguy]

Re: Anyone care to pick apart my parts list for a 17" iMac G5 recap?

Some old eMacs had this issue where bad Nichicon HMs affected the part of the board with ATI graphics on it. If you disabled graphics acceleration, the ATI graphics wouldn't be used and the computer wouldn't crash. Perhaps something similar is going on here? Graphics acceleration isn't going on in Safe Mode?