Welcome to the MacNN Forums.

wongyb · Dec 8, 2005, 11:08 AM

My mac mini has problem rendering JPEG and TIFF image. There are strips on the images.
It can display PNG and GIF without problem.

The image shown in the link below illustrate the problem:

(http://www.flickr.com/photos/terencewong/71481156/)

It also produced very bad video using iLife5. The video generated was similar to an untuned TV channel.

I bought the Mac Mini in the last Februray.
The system Boot ROM version is: 4.8.9f1
Display card is ATI Radeon 9200
Chipset Model: ATY,RV280
Revision ID: 0x0001
ROM Revision: 113-xxxxx-116

I've also tried to flash the firmware to 113-xxxxx-124 using ATI's october 2005 universal ROM update, however, the ROM Revision shown in System Profiler is still 113-xxxxx-116 no matter how many time I reboot the system.

Anyone know how to fix this problem?

Many thanks!

-Terence

mduell · Dec 8, 2005, 05:15 PM

Since it's only happening with specific image types, try reinstalling the OS. If that doesn't fix it I'd guess your video card is on the fritz and you'll need to call AppleCare.

wongyb · Dec 8, 2005, 11:55 PM

Yes, I think so.

I called AppleCare Hotline in my region. The guys there were not able to point out the exact problem and said it might be a conflict in software... I don't believe it is a software problem.
They promised to escalate the problem to senior engineer and will get back to me later. Let me wait for a while...

Thanks a lot!

Originally Posted by mduell

Since it's only happening with specific image types, try reinstalling the OS. If that doesn't fix it I'd guess your video card is on the fritz and you'll need to call AppleCare.

iREZ · Dec 9, 2005, 04:49 AM

i think the japanese characters in ur bookmarks is due to font issues...might be worth a good look

mhuie · Dec 9, 2005, 05:08 AM

I think its the video card or VRAM, I really doubt software would be the culprit.

Originally Posted by iREZ

i think the japanese characters in ur bookmarks is due to font issues...might be worth a good look

Those are chinese characters... :/

mhuie · Dec 9, 2005, 05:09 AM

I think its the video card or VRAM, I really doubt software would be the culprit.

Originally Posted by iREZ

i think the japanese characters in ur bookmarks is due to font issues...might be worth a good look

Those are chinese characters... :/

mhuie · Dec 9, 2005, 05:11 AM

double post...

Fonzie · Dec 9, 2005, 12:44 PM

^could you repeat what you said. I didn't catch it the first time or the 3rd

iREZ · Dec 9, 2005, 01:56 PM

no seriously...i once had a bad helvetica font open and macnn would be rendered in nothing but asian characters. pardon me for not knowing the difference, that was a stupid mistake.

Agent69 · Dec 10, 2005, 12:39 AM

Having problems Mhuie?

wongyb · Dec 12, 2005, 03:54 AM

Thank you for all of your opinion!

AppleCare got back to me. They said the problem is so strange that they were not able to help. Instead they would seek expert opinion from Apple US.

My personal opinion on the problem is:
1) Firmware of the ATI Radeon 9200 card might be too old (113-xxxxx-116). But I failed to upgrade it.
2) Faulty ATI Radeon 9200 card.

As the AppleCare service in my region (Hong Kong) is not efficient enough, would anybody from US do me a favor passing my situation to the Apple in US?

I'll try to re-install the whole system again (though I've done that before) to see if the problem can be fixed magically!

Perhaps, I might try to install another OS...

Thanks a lot!!

Originally Posted by wongyb

Yes, I think so.

I called AppleCare Hotline in my region. The guys there were not able to point out the exact problem and said it might be a conflict in software... I don't believe it is a software problem.
They promised to escalate the problem to senior engineer and will get back to me later. Let me wait for a while...

Thanks a lot!

wongyb · Dec 13, 2005, 04:08 AM

My ATI ROM version is 113-xxxxx-116, which is stone-age old.

What's your Mac Mini ROM version?

Thanks!

tooki · Dec 13, 2005, 01:29 PM

Hardware problems would not be as selective as this, since I assume the machine is functioning properly aside from this.

Did you do an Archive and Install when you reinstalled OS X? If that didn't help, did you try an erase and install (back up files first!)?

tooki

wongyb · 10:23 PM

Thank you for your suggestion!

I did erase and install 3 to 4 times using both the install disc and my Tiger Family Pack. All ended up with strips on the JPEG images and the generated MPEG movies. Other images such as GIF, PNG, TIFF, and BMP are displayed nicely. For movies, AVI can be playback without problem. But when it is converted to MPEG, it looks like an untunned TV channel.

Yesterday, I did some research and got to know that JPEG and MPEG are using DCT (Discrete Cosine Transform) for decompression. And the ATI Radeon 9200 chip provide such a transform on hardware basis, which free the CPU from doing something else. Feel free to point out my inaccuracy.

This images shows what I'm talking about:
http://www.flickr.com/photos/terencewong/73360989/

(Please note that this image is grabbed from my faulty Mac Mini and saved into TIFF. For uploading purpose, I converted it into JPEG on ANOTHER computer.)

I suspect that it is this part of the chip (the DCT) that is faulty.

tooki · Dec 13, 2005, 10:52 PM

I don't think that the Mac uses the GPU to accelerate JPEG decoding.

tooki