RT-AC66U B1 - fixable or not?

[Andrew Leith]

I have an ASUS RT-AC66U B1 that is just out of warranty. I turn it on and all seems well, but after a couple of minutes it's dead, as if I hadn't turned it on to begin with. If I turn it off then on right away, it stays dead, but after waiting a little while, say ten minute, it will light up again only to die a few minutes later.

I spoke with my brother, an electrical engineer, and he suggested looking for cold solder joints. He said that as components run and warm up, that could be enough to flex a cold solder joint and have it break contact,

I'm not an engineer, but I do have enough experience with soldering electronics that searching for, and repairing (re-flowing) a cold solder joint is within my limits.

So I'm wondering if anyone else has suggestion as to what it could be, and if anyone has had this model apart before. The case came apart quite easily, but I'm worried that I might damage thermal pads when removing the heat-sinks. Anyone know where I can get decent replacements if I should need them?

Thanks in advance.

All comment welcome.

Andrew

 

[Natty]

Thermal pads of various sizes, thickness, and thermal conductivities can be found on eBay. I've never taken my RT-AC66U B1 apart so I can't advise what size and thickness is needed. If you look at the temperature graph in the administration tab, does the CPU temperature go very high very rapidly, like over 80 Celsius? If it does, that might suggest the thermal pad is not making a good thermal bond from the CPU to the heatsink.

The other cause could be a bad power adapter. Worth checking if it can hold up the rated DC voltage while powering the router. If you have a DVM and the case is open, you could probe across the DC jack contacts while the router works then dies and see if the issue is power related. Looking for bad solder joints is worth checking if thermals and power supply check out ok.

 

[Deleted member 84281]

First thing i would check is the power supply. These have been known to fail and cause wierd issues

 

[L&LD]

I would not be trying too hard to resuscitate this (older, ac class) router.

Time to go shopping for a new AX class like the RT-AX68U or better.

 

[RMerlin]

Before replacing thermal pads, I would monitor the temperature.

If you can keep it stable long enough to do so, try flashing Asuswrt-Merlin 386.11 on it, then check the temperatures on the Tools->Sysinfo page. If any of these get higher than 85-90C, then that might indeed confirm a thermal issue.

Otherwise, the PSU is also a quick thing to test, if you can get access to a replacement.