MacBook Alu + HP LP2475w external display problem

When I connect my HP LP2475w to my new MacBook Alu using a mini-display to dvi adapter, the external display goes blank every 2 to 5 seconds and then flashes. Got a replacement from the Apple Store. The replacement is better, but still not usable with the external display. Every 2 to 5 seconds, the screen shakes and the lower part of the screen shows snowy flashes. I toke the replacement MacBook back to the Apple Store. Unfortunately they told me that it was a known problem and there was no solution to that right now. They also said that the problem occurred in the mini-display to DVI conversion and that Apple was working on a software fix.

I am sure that the HP LP2475w is not the problem because I am using it flawlessly with my white MacBook. By the way, the HP LP2475w is excellent. I am very glad that I found it. Good price too.

The apple store employees were very helpful and friendly. This makes a bad experience somewhat less painful. I hope Apple will release the fix soon. I bought (and will continue to buy) many Apple products and this was the first time I encountered this kind of problem. I was actually quite surprised that Apple did not catch this easy to find problem earlier.

2.4, Mac OS X (10.5.6)

Posted on Dec 31, 2008 10:19 AM

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7 replies

Jan 15, 2009 10:23 PM in response to HoustonMeow

I'm having the exactly the same problem on my late 2008 macbook when connected to an 22" LG monitor. Every few minutes my screen goes black for a second or two and everything is fine right after. I went through some trouble shooting, *NO CHANGE*. I changed my mini display to VGA, *NO CHANGE*. I tested it out on a 19" hp monitor and EUREKA, all was well but something inside of me wasn't 100% convinced so I went back for an exchange. Tried the new one out on the LG and to my horror the same problem. It's definitely not the LG because I had it connected to a white macbook flawlessly. I called Apple up and they told me they were not aware of the problem. I'm hoping all that's needed is a software fix.

Feb 8, 2009 6:32 PM in response to HoustonMeow

My MacBook/LP2475w combo is usable now after using SwitchResX as suggested in the other external display thread.. There is a slight variation to the instructions in the original thread: I put in a 59.6Hz refresh rate and check both of the "positive sync." options when creating the custom resolution. Now the screen flashes slightly only every two or three minutes. I think the occasional flashes may go away entirely if I use a even lower refresh rate, such as 59.1. I may try it later.

Feb 23, 2009 9:18 PM in response to Digifreak

Had the same issue on my Samsung Syncmaster 2253BW. (22")The problem went away after using SwitchresX to set refresh rate to 60. Before using Switchres the external monitor refresh rate showed as 59.9. I am now happy with my monitors performance and hence my macbook aluminium. Having said that, I feel the pain of all of you who are still waiting for the fix. There is no doubt in my mind that apple knows about the problem and there are people working on it. The time it has taken to fix it seems to indicate that its a difficult one.

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MacBook Alu + HP LP2475w external display problem

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