iMac 2008 not booting

[lucas2205]

Hello,
My grandad gave me his old 2007 iMac last year, i have been using it since and it works just fine, the only problem is that it can't play back 60fps (stutters ALOT), this is due to the underpowered graphics card (specs below). My friend has an 2008 iMac which he doesn't use anymore and it has a Nvidia 8800 graphics card which should be much better. I picked it up yesterday, booted it up, progress bar gets to around 50% then freezes, I opened it up and swaped the hard drive out for the one in my 2007 imac (2tb seagate sshd, completely formated), turned the 2008 iMac on and same thing. So I searched all over the internet for fixes and tried all these:

-tried booting in recovery mode
-tried booting in the internal recovery drive
-tried booting onto a osx el capitain bottable usb drive
-reseted PRAM
-reseted SMC
-tried booting into safe mode
-used different ram sticks

All of these just ended up getting stuck during boot, the only time i was able to get the computer past the grey apple logo screen was when I booted into single user mode, on which I runned: -fsck -fy It returned that my drive was OK. I then tried booting into Apple Hardware Test but holding the D (with or without the alt key too) key down to which it would just go to the grey apple logo boot screen. I was able to enter AHT by making a AHT bootable thumb drive, booted onto it (held alt down) ran the short test and the long test and both returned no errors.

I'm really out of ideas, please help, this is definetly not a hard drive issue so i would think it's a graphics card or logic board issue, I'm willing to replace any part as i have identical parts in my 2007 iMac except for graphics card.
Oh and there was these 2 times where i tried booting into recovery mode, the bar got stuck but i heard "If u wish to use English as your main language, please hit enter" out of the speakers or something like that.

Specs:

iMac Mid 2007
Introduction Date: August 7, 2007 Discontinued Date: April 28, 2008

Processors: 1 (2 Cores) Architecture: 64-Bit

Geekbench 2 (32): 3703 Geekbench 2 (64): 4117

Geekbench 3 (32): 1437 Geekbench 3 (32): 2522

Geekbench 3 (64): 1591 Geekbench 3 (64): 2804

Processor Speed: 2.8 GHz Processor Type: Core 2 Extreme* (X7900)

Turbo Boost: N/A Custom Speeds: N/A

Processor Upgrade: ZIF Socket FPU: Integrated

System Bus Speed: 800 MHz Cache Bus Speed: 2.8 GHz (Built-in)

ROM/Firmware Type: EFI EFI Architecture: 64-Bit

L1 Cache: 32k/32k L2/L3 Cache: 4 MB (on chip)

RAM Type: PC2-5300 DDR2 Min. RAM Speed: 667 MHz

Standard RAM: 2 GB Maximum RAM: 6 GB*

Motherboard RAM: None RAM Slots: 2

Video Card: Radeon HD 2600 PRO VRAM Type: GDDR3

Standard VRAM: 256 MB Maximum VRAM: 256 MB

Built-in Display: 24.0" Widescreen Native Resolution: 1920x1200

2nd Display Support: Dual/Mirroring 2nd Max. Resolution: 1920x1200*

Standard Hard Drive: 500 GB (7200 RPM) Int. HD Interface: Serial ATA (3 Gb/s)

Standard Optical: 8X DL "SuperDrive" Standard Disk: None

Standard Modem: None Standard Ethernet: 10/100/1000Base-T

Standard AirPort: 802.11a/b/g/n Standard Bluetooth: 2.0+EDR

USB Ports: 3 (2.0) Firewire Ports: 1 (400), 1 (800)

Expansion Slots: None Expansion Bays: None

Incl. Keyboard: Apple Aluminum Keyboard Incl. Input: Mighty Mouse

Case Type: All-in-One Form Factor: iMac Core 2 Duo 24" (Al)

Apple Order No: BTO/CTO Apple Subfamily: Mid-2007 - 24"

Apple Model No: A1225 (EMC 2134) Model ID: iMac7,1

Battery Type: N/A Battery Life: N/A

Pre-Installed MacOS: X 10.4.10 (8R4031) Maximum MacOS: Current*

Minimum Windows: XP SP2 (32-Bit)* Maximum Windows: 7 (32-Bit)*

MacOS 9 Support: None Windows Support: Boot/Virtualization

Dimensions: 20.5 x 22.4 x 8.1 Avg. Weight: 25.4 lbs. (11.5 kg)

Original Price (US): US$2299 Est. Current Retail: US$600-US$750

iMac 2008:

Introduction Date: April 28, 2008 Discontinued Date: March 3, 2009

Processors: 1 (2 Cores) Architecture: 64-Bit

Geekbench 2 (32): 4113 Geekbench 2 (64): 4602

Geekbench 3 (32): 1644 Geekbench 3 (32): 2910

Geekbench 3 (64): 1803 Geekbench 3 (64): 3247

Processor Speed: 3.06 GHz Processor Type: Core 2 Duo (E8435)

Turbo Boost: N/A Custom Speeds: N/A

Processor Upgrade: ZIF Socket FPU: Integrated

System Bus Speed: 1066 MHz Cache Bus Speed: 3.06 GHz (Built-in)

ROM/Firmware Type: EFI EFI Architecture: 64-Bit

L1 Cache: 32k/32k L2/L3 Cache: 6 MB (on chip)

RAM Type: PC2-6400 DDR2 Min. RAM Speed: 800 MHz

Standard RAM: 2 GB Maximum RAM: 6 GB*

Motherboard RAM: None RAM Slots: 2

Video Card: GeForce 8800 GS VRAM Type: GDDR3

Standard VRAM: 512 MB Maximum VRAM: 512 MB

Built-in Display: 24.0" Widescreen Native Resolution: 1920x1200

2nd Display Support: Dual/Mirroring 2nd Max. Resolution: 1920x1200*

Standard Hard Drive: 500 GB (7200 RPM) Int. HD Interface: Serial ATA (3 Gb/s)

Standard Optical: 8X DL "SuperDrive" Standard Disk: None

Standard Modem: None Standard Ethernet: 10/100/1000Base-T

Standard AirPort: 802.11a/b/g/n Standard Bluetooth: 2.1+EDR

USB Ports: 3 (2.0) Firewire Ports: 1 (400), 1 (800)

Expansion Slots: None Expansion Bays: None

Incl. Keyboard: Apple Aluminum Keyboard Incl. Input: Mighty Mouse

Case Type: All-in-One Form Factor: iMac Core 2 Duo (Al)

Apple Order No: MB398LL/A Apple Subfamily: Early 2008

Apple Model No: A1225 (EMC 2211) Model ID: iMac8,1

Battery Type: N/A Battery Life: N/A

Pre-Installed MacOS: X 10.5.2 (9C2028) Maximum MacOS: Current*

Minimum Windows: XP SP2 (32-Bit)* Maximum Windows: 7 (32-Bit)*

MacOS 9 Support: None Windows Support: Boot/Virtualization

Dimensions: 20.5 x 22.4 x 8.1 Avg. Weight: 25.4 lbs. (11.5 kg)

Original Price (US): US$2199 Est. Current Retail: US$700-US$850



Please confirm what part is the problem here,
Thanks in advance

 

[BrettApple]

Hate to break it to you but it is most likely the 8800 GS. They are known to go bad along with the 8600m in the MacBooks of the same year. Just Google "iMac 8800 GS" and you'll get a lot of answers on it. Here's a similar post from last year. You can attempt to fix the card by reflowing the solder, but it will only fail again in the future.

The Radeon 2600 was/is a much more reliable card though it is slower.

I'd just stick with the working iMac and not play 60fps videos. I've got a 20" Mid 2007 base model with the 128MB 2400XT and it will still play up to 1080p/30 videos just fine and 720p 60 works as well. It doesn't like the transparency effects in Yosemite/El Capitan too much though, but after turning them off it's fine. Still runs the Adobe creative suite just fine along with Office 2016, Serato DJ, Logic Pro X, and iTunes/Safari etc.

If you need more power you'd be better off with a newer 2012+ Mac.

If you want to test that theory you could try putting the 2600 into the '08 iMac and see if it works. If it does, there's your problem. My brother has a 20" 2008 model with the 2600 Pro and it's been fine all these years.

 

[lucas2205]

Hate to break it to you but it is most likely the 8800 GS. They are known to go bad along with the 8600m in the MacBooks of the same year. Just Google "iMac 8800 GS" and you'll get a lot of answers on it. Here's a similar post from last year. You can attempt to fix the card by reflowing the solder, but it will only fail again in the future.

The Radeon 2600 was/is a much more reliable card though it is slower.

I'd just stick with the working iMac and not play 60fps videos. I've got a 20" Mid 2007 base model with the 128MB 2400XT and it will still play up to 1080p/30 videos just fine and 720p 60 works as well. It doesn't like the transparency effects in Yosemite/El Capitan too much though, but after turning them off it's fine. Still runs the Adobe creative suite just fine along with Office 2016, Serato DJ, Logic Pro X, and iTunes/Safari etc.

If you need more power you'd be better off with a newer 2012+ Mac.

Thx for the reply, I was just reading a post about some guy that cooked the soldering to fix it temporarily. Oh well that's 7h of my life I won't get back. Problem is, is that im only 13, don't have money to get a new imac.
How complicated would it be to completely resolder the graphics card, and how long would it last?

 

[stuartak]

Thx for the reply, I was just reading a post about some guy that cooked the soldering to fix it temporarily. Oh well that's 7h of my life I won't get back. Problem is, is that im only 13, don't have money to get a new imac.
How complicated would it be to completely resolder the graphics card, and how long would it last?

It is not the solder its the graphics chip itself, the "cooking " of graphics cards to supposedly "reflow" the solder is a complete crock. If you watch the videos on Youtube most suggest cooking the card at 385F for ten minutes , well this will not melt solder ! period , however what it does do is distorts the internals of the video chips that sometimes makes the come back to life. However its not a permanent repair but can work for months or in some cases years . In your position with no money and basically free hardware you have nothing to loose , just look it up on Youtube and follow the oven method , its safer than the blowtorch method. But make sure your parents know what you are doing !

 

[lucas2205]

It is not the solder its the graphics chip itself, the "cooking " of graphics cards to supposedly "reflow" the solder is a complete crock. If you watch the videos on Youtube most suggest cooking the card at 385F for ten minutes , well this will not melt solder ! period , however what it does do is distorts the internals of the video chips that sometimes makes the come back to life. However its not a permanent repair but can work for months or in some cases years . In your position with no money and basically free hardware you have nothing to loose , just look it up on Youtube and follow the oven method , its safer than the blowtorch method. But make sure your parents know what you are doing !

Ok I think i might try it someday this week, but before i do can someone please confirm that this is DEFINETELY a graphics card problem and not a logic board problem. I really don't want to dissasemble the imac, take the graphics card out, bake it, put everything back in, then realise it's a logic board problem then have to switch logic boards.

Also can you confirm that the graphics card is not soldiered to the logic board, some people say it is while others say its not.

 

[stuartak]

Ok I think i might try it someday this week, but before i do can someone please confirm that this is DEFINETELY a graphics card problem and not a logic board problem. I really don't want to dissasemble the imac, take the graphics card out, bake it, put everything back in, then realise it's a logic board problem then have to switch logic boards.

Also can you confirm that the graphics card is not soldiered to the logic board, some people say it is while others say its not.

Perish the thought that you might have to waste your time stripping down the machines , I suggest you either go to college and get an Electronics degree or have the good grace to accept the help that people on this Forum are giving .