Posted: Thu May 26, 2022 17:08 Post subject: R6300v2 won’t boot
I have a Netgear R6300v2 that boots intermittently. Once it does boot, the router is stable and works normally. However, after a power cycle this router will remain offline and it takes several attempts to get it to start (it appears to be random when I finally get it up again).
Here’s what I know:
1. I have tested multiple power supplies including known working power supplies and this does not resolve this issue.
2. I have tested dd-wrt, tomato, and genie. The router behaves the same on all firmwares.
3. I cannot establish a serial connection to the router when it is not booting (no output to serial console) which means that the CPU is not starting.
I assume this means there is a problem with a power component on the PCB. I understand basic multimeter usage but I do not know how power is distributed on the PCB so I don’t know where to put the Leeds. Any advice?
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Sat May 28, 2022 12:36 Post subject:
Hey.
So best advice is to look at serial logs when it fails to boot whats going on etc, vs the times where it succeeds to boot.
Both serial logs of good vs bad would be needed for comparison attached to your reply as text files.
It could be your assumptions are correct, serial logs will likely paint some picture either way.
In any case you should be upgrading dd-wrt to latest public build, who knows what is going on with your current version which is likely old and unsupported.
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Fri Jun 03, 2022 13:01 Post subject:
Anyway cant really guess, because how are you able to flash any firmwares at all if the cfe would be affected and when it boots you should be able to connect to serial and get output.
Who knows what happened to it before you posted this here,
Could also be some components are dying, usually the capacitors are the ones I would look at first and replace any faulty.
Some SMD rework maybe needed even, dont know, depends, only looking at the thing under a microscope would be able to tell.
Joined: 04 Jan 2007 Posts: 11564 Location: Wherever the wind blows- North America
Posted: Fri Jun 03, 2022 15:44 Post subject:
I agree with the-joker....its likely a component on your motherboard. You'll have to open it up. Take a close look at the capacitors...they handle the DC power at the input to the Mobo...if one is defective then many times the voltage isn't adequate to start the clocks for proper nvram reads.
I've seen it many times...and fixed many a router by changing caps.
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Fri Jun 03, 2022 22:11 Post subject:
Measure the capacitance of it, you probably have to charge it before, looking at it wont do it. Keep in mind polariy matters for electrolytic capacitors.
Keep in mind too that you cannot accurately check caps in the circuit. It must be removed first. I agree the capacitor looks fine, but while caps usually do swell and leak when bad, this is not always the case. Oh, you will probably need an ESR meter to check it. Multimeters do not do well with caps. Probably your best and least expensive option is to just replace it. It's probably a $0.10 part and since you have to remove it anyway...... _________________ Linksys EA8500 (Internet Gateway, AP/VAP) - DD-WRT r53562
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Joined: 08 May 2018 Posts: 14217 Location: Texas, USA
Posted: Sat Jun 04, 2022 4:48 Post subject:
If it is determined *not* to be a hardware issue, and an nvram erase from CFE prompt or via normal ssh / telnet doesn't fix it, we need serial logs to see what's going on as previously stated. _________________ "Life is but a fleeting moment, a vapor that vanishes quickly; All is vanity"
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Well, another strange issue with this unit. The 4 LAN ports work well, but the WAN port doesn't (link shown as down even with known good cable connected). I realize I could assign one of the LAN ports to the WAN VLAN, but it's probably more trouble than it's worth. Given the other issues, I'll be using this R6300v2 for spare parts.
Sounds like a case of surge bit the device via WAN port. _________________ "The woods are lovely, dark and deep,
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