Aller au contenu principal

Model A1174 with 2 GHz Core Duo or Model A1207 with 2.16 or 2.33 GHz Core 2 Duo

Questions au sujet de 216 Voir tout
Question close

Why is Airport receiving only weak signals after HDD replacement?


Big problem - a client asked me to upgrade the hard drive in their iMac 4,1. It's an older one, with just a Core Duo, not a Core2Duo.

After opening the case and replacing the drive successfully, I put it back together. I installed 10.6 on the new drive, bringing back the files, apps and settings from 10.4, which was previous installed, by way of connecting the old drive via USB.

Everything worked like a charm - except this: the machine couldn't see any WiFi networks when I turned on Airport. I know for a fact there are about ten in range of where I was working.

To test this, I enabled the WiFi hotspot on my phone, and placed it close to the machine, and it could see it, and connect. If I took the phone just outside of the room, the signal dropped.

Same with bluetooth - it will connect to the mouse only if the mouse if pretty much pressed up against the screen.

I open it up again, and checked that the WiFi antenna was connected, and it was. On this model, however, there seems to be only one antenna connected to the WiFi adaptor - grey, in the lower position. Another antenna appears to be connected to the bluetooth adaptor.

When I opened it up, I presumed the foil tape between the LCD and its frame needed to come off, so I removed it. Of course, it didn't. There's not much left of it, so it can't go back on.

Would I be right in thinking that this foil (looks aluminium) should be connecting the edge of the screen and it's supporting frame to create an extension for the antennae?

It's all I can think of - I've checked and rechecked, and everything is connected up right.

I've deleted the airport connection in networking and readded it. However, I haven't reset the NVRAM yet - but somehow, I don't think that's going to do anything. It's clearly a signal strength problem.

As a test, a connected some long antennae wires from an old laptop to both terminals on the WiFi adaptor (even though it only had one wire previously connected), and it seemed to work while they were trailing out of the case, and the thing was flat on its back. I tried securing them inside the case, closed it up, and stood it up, but once again - no signal.

I have some foil tape on order. Can anyone help, or confirm that this is the problem?

Stressing out now!


Répondre à cette question J'ai le même problème

Cette question est-elle utile ?

Indice 0
Ajouter un commentaire

2 solutions

You have correctly diagnosed your problem. You need to foil tape the shield (or reassemble bits of the shield) into place. Check you connected the antenna correctly, and you should be back in business.

If that fails a USB antenna may improve reception.

If this Answer is helpful please remember to return and mark it Accepted.

Cette réponse a-t-elle été utile ?

Indice 0


Thanks, machead3. I actually returned the iMac to its owner yesterday.

For the record, here's the outcome: the tape arrived, and after checking and double-checking that everything was reconnected as it should be, I committed to the act of taping everything up again, making sure to repair any small tears in the EMI shield that had occurred upon removal, even looking for small gaps where the foil had become crumpled up in the corners. In short, it was a thorough job.

Upon starting the Mac, bluetooth is back - the mouse is working as it should - phew! I go to turn on Airport and my heart sinks again - no signals. I could have set fire the to thing and kicked it off a cliff, while saluting, and smoking a cigar.


Anyway, at this point, I wasn't about to open it again. I did bit more testing, and the reception was somewhat stronger than it had been - it would pick up my WiFi hotspot from through a wall now, but it wasn't as good as it should be. In the end, I had to tell the client about this, and offer a nano usb WiFi adaptor as a goodwill gesture. He wasn't really bothered, as he usually connected with an Ethernet cable, which was lucky.

One final thing that noticed, and can't be sure of: I hadn't really noticed then when the machine came in, as the screen was pretty mucky, and I didn't watch it boot up when the old drive was in, but there seemed to be some dark staining in the corners of the screen - mainly top left and lower left. Only quite faint, and only really noticeable on the pale grey screen with the apple logo while booting. At first I thought it was something that would wipe off, but no - it looked like scorch marks, which was very odd.


There's no way of knowing now if this had happened while it was in my custody, but if it had, I wonder if it's possible that running the machine with all the foil disconnected could have cause this? The inside of the thing was getting pretty hot...

Anyway, hopefully this post will be of use to someone in the future, if only in a consolatory capacity.


Ajouter un commentaire

I recently replaced the hard disk drive on an Intel core duo iMac (A1174). After getting the machine up and running, I found that the wifi signal was very weak. It could see only my own WiFi SSID but was unable to connect to it.

I connected a Compaq Presario antenna and cable to the WiFi card and the system picked up a strong signal and was able to connect to my WiFi. The conclusion was that it was something to do with the WiFi antenna and cable. The problem was that I couldn't understand how changing the hard disk drive could cause this problem.

I decided I would replace the apple antenna and cable with the Compaq Presario laptop one. I started working out how and where I would place the new antenna. I also put the card in at the back used to remove the front bezel to see how it would impact on the antenna. This is when I saw what had caused the original problem. The card was snagging on the WiFi antenna cable. I realized that when I was attempting to release the front bezel catch I was having problems with it and I moved the card towards the centre and snagged the WiFi cable. This had damaged the WiFi cable; in my case near where the outer wire in the cable is exposed and connected by conductive tape to the EMI shield.

I took out the WiFi antenna and cable. Cut the cable to take out the damaged area and after removing solder from the antenna pads re-soldered the cable back to the antenna.

Also exposed part of the outer wire on the cable so that it could be connected to the EMI shield.

Once the antenna and cable was back in place I found that the problem had been resolved. The WiFi now had a full signal. Also tested the Bluetooth and managed to successfully transfer a file from the iMac to my laptop via Bluetooth.

The EMI shield I believe plays a part in expanding the WiFi antenna especially when it's connected to the outer parts of the lcd.

I don't think the EMI shield has anything to do with staining the lcd screen as mentioned by DeathOnRedBull. Apart from helping to expand the WiFi I think it's purpose is to stop the iMac interfering with other devices.

Cette réponse a-t-elle été utile ?

Indice 0
Ajouter un commentaire
Nombre de vues :

Dernières 24 heures : 0

7 derniers jours : 0

30 derniers jours : 0

Total : 384