iMac won't upload anything. Please Help!!

[thetofso]

I'm getting fed up with this...

My iMac won't upload anything, whether it's pictures, music or movies, to Dropbox, Facebook, Gmail, or anything else. It's not my network since my MacBook Pro uploads fine and I've tried the iMac on several different network connections.

Speedtest.net does fine with ping and download, but once it gets to upload it just freezes at 0.00. Once in a blue moon, when it gets to upload, the meter gets a sudden surge to about 0.30 Mbps, after which it slowly decreases to 0.00, and freezes there.

A while back my iMac's internet (download and upload) was lagging, so I did a full clean install. It worked fine for a while, but, lo and behold, after a month or so my upload completely stopped working.

I've deleted the whole SystemConfiguration folder and created a new location. I've tried using all sorts of DNS servers. I've tried different MTU values. I've tried different browsers. I've tried everything. Someone please tell me there's a way to fix this.

I'm running OS X 10.9.3 (Mavericks) on a 21.5 inch Mid 2011 iMac.

Someone, PLEASE PUT ME OUT OF MY MISERY!

 

[khedden]

Is your iMac connected via WiFi or wired Ethernet?

If one, try the other. If wired, you should try a new Ethernet cable straight into your cable modem or DSL modem. Eliminate any device you can (e.g. router).

 

[thetofso]

Thanks for the reply.

I was using WiFi. I had also tried tethering my Android phone to the iMac and using the 4G (LTE) network, which works fine on my Macbook (it's actually considerably faster than my WiFi).

Anyway, once I connected the iMac to the modem with an Ethernet cable, I actually got a 0.50 Mbps upload speed, and was even able to upload a file to Facebook.

WiFi still doesn't work, nor does the Android's network. So, apparently, the Ethernet connection isn't disrupted by something that the WiFi and USB tether are. Any ideas what this might be?

 

[khedden]

Thanks for the reply.

I was using WiFi. I had also tried tethering my Android phone to the iMac and using the 4G (LTE) network, which works fine on my Macbook (it's actually considerably faster than my WiFi).

Anyway, once I connected the iMac to the modem with an Ethernet cable, I actually got a 0.50 Mbps upload speed, and was even able to upload a file to Facebook.

WiFi still doesn't work, nor does the Android's network. So, apparently, the Ethernet connection isn't disrupted by something that the WiFi and USB tether are. Any ideas what this might be?

Is 0.50 Mbps what you expect from your Wifi network?

So, to sum up:
Macbook -> Wifi = works fine
Macbook -> Hotspot 4G = works fine

iMac -> Wifi = doesn't work at all
iMac -> Hotspot 4G = doesn't work at all
iMac -> Ethernet = works fine

Is that correct?

If so, it points to some issue with your iMac's Wifi. No idea what this might be. I've never heard of the Wifi chips going "bad" or anything like that. Could be some kind of strange software issue, I suppose. But again, I'm not familiar with such an issue.

I would say that it could be a problem with your router configuration, but since your 4G hotspot doesn't work either, it kind of rules that out.

Sorry I can't be of more help.

 

[thetofso]

Is 0.50 Mbps what you expect from your Wifi network?

Sadly, yes, 0.50 is pretty much what I expect from my WiFi. The upload speeds in Finland are typically pretty rubbish (except for 4G networks).

So, to sum up:
Macbook -> Wifi = works fine
Macbook -> Hotspot 4G = works fine

iMac -> Wifi = doesn't work at all
iMac -> Hotspot 4G = doesn't work at all
iMac -> Ethernet = works fine

Is that correct?

That's right, but notice that the 4G hotspot doesn't work no matter if I'm using a wireless hotspot or a USB tether with a USB cable (using HoRNDIS: http://joshuawise.com/horndis). This means that it's probably not strictly speaking a WiFi issue, right?

The funny (more sad than funny, really) thing is, that, as I mentioned, I had network issues before, which led me to do a clean install. But, after a while, network issues arose again. Could this be just really, really bad luck, or is it really a hardware issue? If so, how come the network work fine for a while after the clean install...

I'm baffled.

 

[khedden]

Sadly, yes, 0.50 is pretty much what I expect from my WiFi. The upload speeds in Finland are typically pretty rubbish (except for 4G networks).



That's right, but notice that the 4G hotspot doesn't work no matter if I'm using a wireless hotspot or a USB tether with a USB cable (using HoRNDIS: http://joshuawise.com/horndis). This means that it's probably not strictly speaking a WiFi issue, right?

The funny (more sad than funny, really) thing is, that, as I mentioned, I had network issues before, which led me to do a clean install. But, after a while, network issues arose again. Could this be just really, really bad luck, or is it really a hardware issue? If so, how come the network work fine for a while after the clean install...

I'm baffled.

Yeah, it's confusing.

Could be a Wifi issue with the iMac (which has an airport card, I believe). But the tethering problem and the (brief) clean install success puts that in doubt.

Could be a router problem, but the Macbook Wifi success puts that in doubt.

Could be wireless interference if you live in a crowded apartment building, but Macbook Wifi success puts that in doubt.

Could be a weird software issue. The clean install working then turning sour could support this, but it's hard to say.

Things that I would try:

a) Uninstall any and all third-party networking software you have, such as the HoRNDIS product you mention above. Do another clean install if you have to and install nothing else until you are able to fully test the Wifi.

b) Try a different wireless router. They can vary widely in performance and compatibility. Borrow one or buy one from a place with a generous return policy. Since you have Macs, I would recommend an Apple Airport Express (or Extreme if you have the cash for that).

c) If nothing else resolved the issue, then I would start thinking about cracking open the iMac and replacing the Airport card inside. If you have no or little experience working with the guts of computers, DO NOT DO THIS. I've opened a lot of Macs in the past, going back to the original Bondi Blue ones, so it's a possibility for me.

If I were to bet, I would bet on (a) being the problem. The fact that only upload is affected sounds like a weird software issue. The fact that your Macbook Pro works seems to rule out wireless problems outside the iMac.

Good luck!

 

[thetofso]

Yeah, it's confusing.

Could be a Wifi issue with the iMac (which has an airport card, I believe). But the tethering problem and the (brief) clean install success puts that in doubt.

Could be a router problem, but the Macbook Wifi success puts that in doubt.

Could be wireless interference if you live in a crowded apartment building, but Macbook Wifi success puts that in doubt.

Could be a weird software issue. The clean install working then turning sour could support this, but it's hard to say.

Things that I would try:

a) Uninstall any and all third-party networking software you have, such as the HoRNDIS product you mention above. Do another clean install if you have to and install nothing else until you are able to fully test the Wifi.

b) Try a different wireless router. They can vary widely in performance and compatibility. Borrow one or buy one from a place with a generous return policy. Since you have Macs, I would recommend an Apple Airport Express (or Extreme if you have the cash for that).

c) If nothing else resolved the issue, then I would start thinking about cracking open the iMac and replacing the Airport card inside. If you have no or little experience working with the guts of computers, DO NOT DO THIS. I've opened a lot of Macs in the past, going back to the original Bondi Blue ones, so it's a possibility for me.

If I were to bet, I would bet on (a) being the problem. The fact that only upload is affected sounds like a weird software issue. The fact that your Macbook Pro works seems to rule out wireless problems outside the iMac.

Good luck!

Thanks for the suggestions!

Uninstalling HoRNDIS did nothing, and I don't think I have any other software that should directly affect the network. I'm really hesitant on doing another clean install, as I don't like the idea of having to install all my apps and things again etc., especially when chances are that the same thing's just going to happen again...

I could try a different router, but then, my Android phone's wireless hotspot doesn't work either, and the MacBook works fine, which suggests, as you say, that it's not a router problem.

Something I didn't mention is that, before the clean install (when my internet was lagging), I had Boot Camp Windows 7, on which I had no network problems whatsoever. This hints that it is indeed a software problem inside OS X, but I can't for love nor money figure out what exactly could be causing it. I'm thinking of installing Windows to see if it would work.

Also, before the clean install, I could at least upload files, even if the connection was a bit slow. Now I can't do that at all.

 

[Nyy8]

I thing I like about troubleshooting is isolating one part. if you have the time install Windows, and try to upload something.

At least then you know it's a problem within OS X, and not your WiFi Chip.

 

[thetofso]

if you have the time install Windows, and try to upload something.

As expected, upload works fine on Boot Camp Windows 7. So, it's an OS X problem. But what the **** could it be?

 

[mossy]

4G driver might not be compatible with the hardware in your iMac. What year is your laptop?

I had a 2009 iMac that stopped working with my router after an update before (ethernet and wifi). It turns out it was a driver update I installed, that was not compatible with something inside the Belkin router I was using. I ended up buying an airport extreme.

Me thinks it has to be something along those lines.

try rolling back to an earlier version of OS X 10.9

 

[eduardrw]

I was about to suggest to debug the router.
What router do you have? - do you have a second one to test?

Option click on the WIFI icon in your iMac's toolbar - what are the RSSI and transmit rates?

Use a program (money) like iStumbler or WIFI scanner to see if there is interference on the wifi band you are using.
Check if the channels you are using are crowded by neighbors - if so change them.

If that does not help you might do the clean install - don't install and then restore from backup etc!

Check after the clean install what the upload/download speed are - use http://www.speedtest.net for example.