My ADSL connection had been getting very flakey recently, rebooting the router would always fix it but I was having to do this more and more. I had read lots of reports about the Teapo capacitors in the Netgear DG834 router failing so I decided to replace them. They looked okay but apparently they can fail without spewing electrolyte or swelling up. The original caps were 1000uF but since I only had 1500uF ones I used them. As you can see from pic.1 I had to lay them over to fit in the case. There’s also a Teapo 100uF 25V which I replaced with an equivalent.
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While I had it apart, I noticed that the back of the PCB below the main CPU was looking discoloured and this chip was obviously getting very hot, so I cut up an old video card heat sink and super-glued it to the top. This seemed to really help my connection speeds and for a few days we had no problems but then it started dropping again. I opened the Netgear up without turning it off and felt the heat sink – it was hot enough to burn my finger! So leaving the top off, I placed  a cooling fan over it and almost immediately it started working again (and most importantly without needing a reboot).

Clearly the Netgear needs better cooling and here is my solution –two 50mm fans connected in series to the PSU socket pins, one fan is inverted to blow air in and the other sucks it out.

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I used two 12V fans and wired them in series to keep them running quietly at half power. Needless to say the whole router stays very cool now and so far my connection is much better than before.

After trialling this setup for a few days, the broadband has stayed up and I haven’t had to reboot the router but I’m still not getting a consistent connection – speed test results are variable. It could be the work that BT are doing to prepare for BT Infinity on our exchange but I’m also wondering if the Netgear’s overheating chip has stressed the ball grid array under it, to breaking point?

Update: It worked much more reliably but we finally managed to get PlusNet fibre installed on October 24th and haven’t had a single outage for two months. We’re now getting a solid 12Mbps up and 55Mbps down.