Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Hi guys, sorry for the long wait for my reply, I have been buys and hadn't checked this post for a while. ^_^
To answer your question about the tea-light re-flow method, it is done with the iMac turned on (the help heat up the chip internally as well as externally), and I found that a single full tea-light "cup" of alcohol burned for about 20 or 30 mins?, and was enough to get the iMac to POST and boot fine again, however it never stuck for longer than a few days at best.
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sylphhawkins
Member
Last Activity: 05-02-2013, 07:28 PM
Joined: 03-31-2011
Location: Melbourne, VIC
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
@ easez
Personally I don't have any experience working on the intel iMac's that were still in white cases (only the G5 iMacs and then the Aluminium+glass intel iMacs), but have you had a look at the you tube link I posted above, showing a repair shop talking about a White iMac Intel CoreDuo?, I can't remember if they stated what the LED status was on the logic board before they did the reflow and repair?, maybe they also only had 1 LED lit? (usually, on the iMac's, 1 LED lit on the motherboard indicates...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Hoho!
To everyone who is watching this thread about the iMac 7,1 repair.
I seem to have been able to isolate my problems (and the repair ^_^ ) down to the Northbridge chip. On this model (a mid-2007 iMac 7,1) the northbridge chip is an Intel SLA5U.
Removing the heatsink and performing a quick DIY reflow of the chip (I used an old tea-light candle tin cup filled with methyl spirits, and set it alight with the imac powered on, to heat up the northbridge chip enough to...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
*UPDATE*
Hi again,
I wanted to quickly update everyone who's following this thread, with "yet" another note about the iMac 7,1 20" 2.4Ghz repair.
I had put it aside for a while, to work on fixing up my new present I bought myself (a water damaged (or should we say, coffee damaged) Macbook Pro 15" 2009 that I found on ebay super cheap, ^_^), and now that that's up and running superbly (I'm writing this post on it right now), I decided to crack open the iMac...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Hey Keebler64,
Thanks for the notes on reflowing the GPU with the alum shield and heat torch method. =),
I've come to the conclusion that I well fried the original GPU card after doing an oven reflow and getting distracted, =(, "woops", =p
still, I ended up finding a cheap HD 2600 GPU card on ebay (pulled working from a working iMac with LCD screen damage).
I popped that in and after a bit of fiddling, (I think I might have tried reseating RAM, scrubbing the...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Hi Everyone! - Sorry for the long quiet delay on the posting front, been busy busy. ^_^
I thought that this post might have been the "all working again" final post, as after receiving the replacement 2600 HD video card, the iMac went back to exhibiting it's usual behaviours, sometimes it would chime, sometimes not, and it would always freeze by a few mins in at the best of times, but the normal freezing time was before boot, during the spinning gear.
Then, I decided to tighten...Last edited by sylphhawkins; 05-02-2011, 04:56 AM. Reason: colour code didn't work initially with RGB values, so I changed it to the "colour wording" of SandyBrown, =)Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Hi everyone,
Just a quick update:
The refurbished imac PSU arrived today, and installing it has made NO difference at all to the problem + symptoms, which currently are:
iMac will NOT chime or boot, (+ black display) with the current ATI Radeon 2600HD video card installed,
but the iMac will boot and chime fine, and can be remotely accessed and controlled (SSH and screen sharing) when I remove the video card.
So, I'm going to give the Radeon...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Wow, epic post Numnutz2005, thanks for contributing what you've been finding working on the same model imacs, that's awesome. =)
I have thought about baking the GPU to reball the BGA, but I haven't been convinced that its the chip BGA thats the problem, although, I suppose that it could make sense given that it stopped working after removing the heatsink, perhaps the heatsink was adding a good amount of pressure on the GPU, which, when removed, took the pressure off the BGA and allowed a few balls...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Hi Scenic,
Maybe, but the iMac hadn't been on for long enough for the GPU to heat up to a point that would damage the DDR3 chips, especially as they were still cool to the touch when I removed the card to re-look over it again.
Ironically, more than the issue with the HD2600, I'm excited that I've been able to get a bit more consistent control over the whole iMac problem, and work it down to a fairly consistent (if this : then that) way of replicating the Power and Boot issues....Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Sorry for the delay in getting back to the topic guys,
I've had a few developments in the iMac's non-booting, no-chime, but power on problem
After a long and tedious process, =p , I discovered that I could actually get the iMac 2007 to boot with chime, when the SMC reset "switch" point was shorted out on the logic board (it's on the underside, next to the CPU, and also has a friend, simply named "SYS reset", both are blank mounting points, but can just be shorted out across...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Ok great, thanks Toast, at least that rules that out.
I tried a new NVRAM / SMC battery today, and it hasn't made any difference to the problem. A "refurbished" PSU is on it's way, so I'm hoping that the problem is the PSU, and not the motherboard, but I guess I'll find out when the new one arrives.
I'll get in an check the voltages tomorrow too, and post up what I find running on the 12v rails.
^_^
- sylphLeave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Ok, Hey again everyone,
I've managed to get some photos close up of my PSU, but unfortunately it seems that my camera just isn't able to get a detailed photo of the whole board, so there's both the wide photo, and a close up photo of the top right hand side components which have the burnt flux colour residue on them.
On the close up photo, you can clearly see the burn out colourings on Q33, D41, Q32 and D45.
What do you guy think?, i've gone over the board and re-soldered...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Thanks for your reply Toast, that's an awesome amount of info and resources that you just put forth. ^_^
In regards to the board caps, I removed and tested them (just a voltmeter capacitance test), and then replaced them with new spares that I had on hand anyway, since they were out, and although I managed to do a terrible solder job (my 45w iron just didn't cut it), getting the new caps on the board hasn't changed the situation at all.
You're right about Pin 4 being the PSU temp, i've...Leave a comment:
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Re: Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Definitely, I'll get a close up photo of the underside of the board, and post it up as soon as I can. ^_^
As an update, after a little bit of hunting around online, I found a US ebay seller, selling "refurbished" PSU for this model of iMac, to match the same EEE code, for only $39 inc. postage!, so I've bought one, and it's hopefully on its' way.
I really want to:
a) try it, and hope that the iMac boots!, and that it doesn't turn out to be a logic board issue, =p
...Leave a comment:
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Aluminium intel iMac (2007 model), wont POST, no chime, bad PSU?
Hi Everyone, I initially posted this question in a different thread, but I think that it deserves its' own specific place on the web.
Here's the original post:
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Basically, I have one of the aluminium intel iMac 7,1 (mid 2007) 20' 2.4ghz models, with a 614-0403 power supply.
The imac has a problem where 90% of the time, it will power up (3 of the 4 diag LED's light up on the motherboard), with no chime, DVD and HD spins can be heard, and fan's power on, then it will shut down (usually after only 3 or 4 seconds),... -
Re: iMac P/S posts then shuts down
Woops, Point taken, ^_^
I am talking about an Aluminium Intel iMac (mid 2007 model), but it is exhibiting exactly the same problem as godonr, so I thought that maybe it would possibly be linked the same problem. =)
I'll make a new post and ask the question again, =p
- SylphLeave a comment:
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Re: iMac P/S posts then shuts down
Hi godonr, =)
Thanks for the idea, i thought that perhaps there was a HD issue, so I pulled the HD out, and the problem remains the same, i've also loaded the HD in an iMac G5 that i fixed, and it's working perfectly, =p, for now, the G5 has also inherited the bluetooth card from the C2D until I can get it working, ^_^
The strange thing though, is that I have been able to get the 20' iMac to chime and boot, with perfect display and everything working great, but only after some random trials, and it only remained on for...Leave a comment:
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Re: iMac P/S posts then shuts down
Hi guys, this is my first post (after a year or 2 of reading posts on badcaps, I finally registered because I have a problem that I haven't been able to fix from hunting down anyone else's posts, =p), and I'm aware that this may not the best thread to put it up in, so please let me know if I should start a new thread elsewhere, =)
Basically, I have one of the aluminium intel iMac 7,1 (mid 2007) 20' 2.4ghz models, with a 614-0403 power supply.
The imac has a problem where 90% of the time, it will power up (3 of the 4 diag...Leave a comment:
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