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Was anyone ever able to run AHT or ASD on these 2010 kernel panic unit

Hi folks, I am trying to keep 2010 15”machines in circulation: I have been trying my hand at refurbishing these machines which kernel panic, by replacing the Tantallon Cap in the GPU rail, to stop the random shut downs. It seems that 90% of the time I succeed, but I have 2 machines with new caps installed which after a few weeks started to randomly shut down again. I have been looking for possible other causes and fixes, but nothing seems to do it. Worst, I cannot even run ASD nor AHT on any of these machines for some reason, which seems to be a common problem with that year according to Apple forums . Does that mean that I actually have to replace the GPU chips in those units? Also I am hoping that someone can link me to a page where I can get help interpreting kernel panic report in general, or this one here in specific: nonymous UUID: 400E10CA-01CD-0007-6971-71A40DC343E0

Отвечено! View the answer У меня та же проблема

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Since the issue with these machines is random shutdown related to the GPY circuit, can anyone recommend a GPU testing software,or really any diagnostic software, so I can make sure that my machines will not fail due to Mux chip weakness or GPU failure down the road when stressed?

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@arbaman, thank you so much for your help, I very much appreciate your input, and your confirmation on “Heaven” being a good tool. ( I was worried that I might further damage a board with such a program). Since exchanging the C9650 alone did not resolve the issue on some boards, your pointer to check the resistors around U9600 is just what I needed. Did you find that there are specific next weakest link in the chain on that GPU rail? And also, do you know how I can check caps while on the board? I have not yet found out how to measure capacitance yet…there are still so many gaps in my understanding…..but I will get past them with some help.

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Actually I’ve never used any Apple “hardware test”, my trusted tools and schematics are usually all I need to test boards, thus I can’t answer to the question as to why it doesn’t work or how to make it work. When I think at 820-2850 faulty graphics I’m so thankful towards the guy who found out about that crappy cap at the end of a graphic buffer rail and wish I had the chance to buy him at least a drink one day, great sense of community and sharing from him. That said, that’s the only “plz bro” solution I know with these boards. The infamous cap goes bad only after years, but on a 8/9 years old board things that may go bad are quite a bit, graphic circuitry is big and you have all the Mux part too that is not to be neglected during testing. I’d avoid replacing the graphic chip as that is very seldom cause of the problem and concentrate on resistors and Mux. If you don’t feel like wasting hours probing resistors I can understand, just be happy with the 9/10 you fixed without any effort and call it a no fix ;) Just my 2 cents..

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Thank you arbaman, and yes, I simply adore Louis Rossmann as well. I learned since how to read the surface of the error report on the machine I am referencing, and the Mux chip is indicated there. Did you ever replace one of those? Maybe Rossmann sells them, I must look...

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@jurgenkoppen I've done a few reballs on Mux, but it proved to be useful only once on a previously reworked board, heaven only knows what they did on it before ;) AFAIK is not bound to anything special, thus in case needed I'm pretty sure it can be just replaced. I'd check all resistors around U9600 before replacing anything. BTW, not sure who's the guy who found out first about C9560, I wouldn't feel confident on betting on anyone :)

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I just got a program called Heaven, apparently can be used to benchmark GPU performance. I ran it on my most recent Ebay supposedly working machine, it crashed within a minute...So that will tell me if a machine it fit for resale....I suppose...

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@jurgenkoppen Whatever the issue originally was, I use Unigine Valley, or Heaven for older machines, for the same purpose too before returning the Mac back to customer. As you said, a faulty GPU can hardly withstand a minute running the App.

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@jurgenkoppen Not a problem, I'm glad to help if I can. Besides what I've already reported there's not much guidance I can help with, I know checking resistors is a time consuming and tedious job that might as well not be resolving but there's nothing else I'm able to recommend. If you have a known good board that might help speed up things rather than going through schematics component by component. Diode mode testing may be of great help too when it comes to QFN ICs.

Capacitors cannot be tested on the rail as that would give an overall meaningless capacitance, one has to necessarily remove them.

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Jurgen будет вечно благодарен.
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