Sorry if this is long winded. I feel like I've spent years here and there trying to figure this out and I want to share the specifics because no two MBP problems are alike. After all this hassle, I now have a 2010 MBP running Mavericks that is up to date, connects to WiFi like a charm and doesn't disconnect intermittently (also, no more black screen since I deleted the Windows partition anyway).
I have a 2010 MBP. I had it bootcamped with Windows 7 Ultimate because the mac HD wouldn't connect to WiFi. Then over the past year or two, I was experiencing a black screen issue whenever I used a browser in Windows 7. Doing a little research, I noticed that the black screen was due to a "graphics switching setting" in the Power settings on the mac side. Unfortunately, the mac HD OS X must've gotten corrupted (probably due to lack of updating and use, etc.) so I couldn't boot into mac to change the setting. Low and behold, I was left with a 3.5 year old machine that I paid $2k for and couldn't connect to the Internet or use a browser without having the restart the machine every 15-20 minutes.
Problem Summary:
#1 Mac couldn't connect to WiFi (connection timeouts, dropped signals)
#2 Couldn't boot into Lion OS X (probably a personal problem since I never used the Mac side without Internet)
#3 Couldn't use browser in Windows 7 (graphics switching setting in OS X)
Here are the steps I took to resolve each problem. A lot of these steps utilized some tips and suggestions I found on the Apple forum, Verizon FIOS forums (I have a MI424WR-1 modem/router) and on general mac/tech forums.
Problem 1 fixes:
Changes to Router Settings - Following Apple and Verizon's suggestions (Diagnostic Tool - run it and read the WiFi settings info), I made the following changes to the Router and Mac Network settings:
- Router Resets - I did the whole router reset via admin panel and on local modem. WiFi would connect but would disconnect upon sleep or just intermittently for no reason. Not a permanent fix.
- IPv6 vs. IPv4 DHCP - I enabled IPv6 on my router to see if that would provide a more stable connection. After all the research and troubleshooting, I was starting to believe that the MBP needed a static connection of some sort but I'm too much of a novice to figure that out.
- Security Settings - I actually disabled password-protection on the router and still couldn't connect to WiFi
- MAC Address - I tried enabling my MBP's MAC address to have access to the router, but that didn't work either.
- WEP vs WPA vs WPA2 - I tried all of these. WEP is definitely out of the question. I settled on WPA2 but I still couldn't connect smoothly and would lose connectivity.
Changes to Mac Network Preferences
- Keychain - I tried deleting all the airport preference files. Did it multiple times. Restarted machine as instructed. Not a permanent fix.
- TCP/IP - I tried putting my MAC address as the DHCP Client ID and changed the IP settings (auto versus manually inputted). Also tried to Renew DHCP Lease, but that rarely worked since the MBP just wasn't able to communicate to the Verizon MI424WR-1 router. IPv6 didn't make much of a difference either. I tried adding a new Location, adding/deleting preferred network and trying new IPs but none of that made a difference.
- Hardware - I also tried to change the MTU to manual setting of 1453 because I read that in a forum. Didn't make a difference (also changed on the router settings).
At this point, I had probably restarted my machine 2 billion times. The more forums I read, the further down the rabbit hole I fell. Worst part of it all? In every single forum I read on Apple's site, there was not a single - NOT ONE - reply from anyone at Apple. So, if you're looking for help from your ISP or from Apple, you're out of luck on this one.
Problem 2 fixes: This is probably an isolated problem, but thought I'd share since all these fixes occurred on the same weekend. Also, I've read here and there to make sure your OS X is up to date because that can also cause communication problems with certain routers. That said, I made a bootable USB with Lion OS X. Since I did not have a functioning OS X to do this on, I made the bootable USB via the Recovery HD. I completely reformatted the MBP HD. Being connected to Ethernet, I updated the software all the way to Mavericks and then I deleted the bootcamp partition so all 500gb were allocated to MBP HD. So, at this point, I had a MBP with a fresh copy of Mavericks - completely up to date - that still couldn't connect to WiFi. So not sexy.
Problem 3 fixes: At the end of the day, this one doesn't matter to anyone who wants to run OS X without bootcamp. However, if you're getting the intermittent black screen and having to restart Windows all the time, you will need to boot your MBP HD and change the "graphics switching setting" in System Preferences > Power. Just uncheck the box and reboot back into Windows. Should be good to go.
****END RESULT****
I bought a dual band wireless N router (Linksys E2500, $80). Problem solved. I'm not even joking. Oh, by the way, if you do plan on buying a replacement router to get the broadband signal and speed your MBP needs to connect, make sure the router set-up disc can be read/opened in Mavericks. Thankfully, I had a Windows 8 HP I could use to install and set up the Linksys router; otherwise, I wouldn't have been able to get the new router to speak to the old modem.
Now I can close my MBP lid and reopen and the WiFi connects instantly without hesitation. I can restart my MBP and the WiFi magically connects as it should. I can even download large files over WiFi without any connectivity loss. I tried to fix my machine as cheaply as possible. Apple Care was expired and I didn't feel like paying someone for a temporary fix. Update your MBP to Mavericks for FREE today through the App Store and go out and buy yourself a 2.4ghz/5ghz dual band Wireless N Router.... perhaps Airport Express will work too?
RANT 2.0 - It really ticks me off that after being such a loyal Apple and Verizon customer all these years that one of these companies would give a hoot about this problem. Apple knows it's a router issue and perhaps even a greater issue with all OS X versions since Mountain Lion? Who knows, I don't work there. Also, it drives me crazy that an ISP won't give a legacy customer a newer router that handles dual band. Verizon told me that those routers only go to new customers and that they'd happily replace my old router with a refurbished version. It ***** they won't listen. It ***** they won't help. At the end of the day, buying a $80 router was a lot cheaper than $$$ for Apple Care extension (and the time without a computer) or breaking up with Verizon so I could be classified as a "new" customer.
Forum references:
WiFi Connection Timeout - Macbook Pro?? Help! - goes through the system preferences tips and suggestions. None of these worked for me.