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RB750 hardware reliability

Posted: Fri Jul 22, 2011 8:09 pm
by OriiOn
I am now having my third RB750 out of 10 which has died with all LEDs on/green, within a 18 month time period. Usually the hardware dealer replaces it without any problem, but I wonder how reliable the routers really are? A 30% hardware failure rate within 18 months is quite unusual. Was it just bad luck, or is this what one has to expect for this price-range? What's the experience of other customers?

I am quite happy with the overall design of the router and the functionality offered, and would not like to switch. Are there other RB models with a more reliable hardware? While browsing the forums I got the impression that the capacitors are a particular weak-spot, is this correct?

Re: RB750 hardware reliability

Posted: Fri Jul 22, 2011 10:49 pm
by Ciambot
I also have too RB750 broken: all leds are on.
I like RB750, but I think they are only for soho user... don't use in your backhaul!
I advise you to don't put above other device: they suffer warm air.

Re: RB750 hardware reliability

Posted: Sat Jul 23, 2011 2:53 pm
by OriiOn
I think you are right about the "heat" problem: the failing devices did operate in a warmer environment. But really nothing unusual, there's lots of other equipment that performs without any problems. So that is not really satisfactory.

My question would be, which other RB models are known to work (more) reliably? I understand that the RB750 is the smallest model with limited performance capabilities, albeit more than sufficient for our requirements. So ideally I'd be looking for something similar to the RB750 feature- and performance-wise, coupled with reliable hardware.

Re: RB750 hardware reliability

Posted: Sun Jul 24, 2011 1:54 am
by glucz
We had a few 750's die too (3 out of 10). If you take them apart, you will see 2 large capacitors in the middle. Most likely they are deformed and the top is blown or split. Replace them with solid state capacitors. They are in the $1 range each, so your total fixing cost is $2.

This is a common problem with electrolite capacitors in high demand environments and it is also why most new motherboards use solid state capacitors. Most PC power units die because of this as well. We are in the dedicated server business and I have to replace these kinds of capacitors by the dozen every week.

The only problem with the 750 is that they are not easily serviceable. You will break off a few plastic hinges when you take them apart, so make sure that enough of them remain to lock the unit when you put it back together.

When the 3rd one broke, I took a couple of pictures to send to MT, but I seem to have lost them now.

If you store the router on top of other routers or where they are subject to some kind of heat, the capacitors will die quicker.

GL

Re: RB750 hardware reliability

Posted: Mon Jul 25, 2011 6:10 am
by nz_monkey
Seems pretty reliable here

Re: RB750 hardware reliability

Posted: Mon Jul 25, 2011 12:40 pm
by OriiOn
We had a few 750's die too (3 out of 10). If you take them apart, you will see 2 large capacitors in the middle. Most likely they are deformed and the top is blown or split. Replace them with solid state capacitors. They are in the $1 range each, so your total fixing cost is $2.
Thanks for the valuable information! Can you tell me please the precise model/brand name that you replace them with, since you seem to have lots of experience with it and know what works. Personally I am not a "hardware guy", but will pass the information on to a colleague, who could go ahead and have the capacitor replaced on one of the broken devices. Thanks!

Re: RB750 hardware reliability

Posted: Mon Jul 25, 2011 4:32 pm
by glucz
Currently all of them are working, so I won't break one open now. But you have to take it apart anyhow, so just look inside to see if it is really the capacitors that blew. Search for blown capacitor in google to see how they look like.

Look on the side of the capacitor for a capacitance and a voltage value. Get something that has the same or slighly larger voltage tolerance and the same capacitance value. If for some reason you don't have the same capacitance value, you can use one in a +-15% range. I seem to remember that the original value was 510uF and I used 470uF instead.... if you use the same electrolite capacitors, that will give you a few more years. Solid state capacitors will be more expensive, but should give you a minimum of 5 years. The exact brand doesn't matter.

GL

Re: RB750 hardware reliability

Posted: Mon Jul 25, 2011 6:02 pm
by OriiOn
Thank you very much! I will try that.

Re: RB750 hardware reliability

Posted: Fri May 11, 2012 11:09 pm
by glucz
... I know that this thread is almost a year old, but I came across another broken routerboard.

This is the same problem that I saw in a few 750's (that this thread is about) ... this is a 450.

I looked into one of the newer 751's and there seems to be only solid-state capacitors inside. So hopefully the newer models will have a longer expected lifespan than the old ones with electrolyte capacitors.

Re: RB750 hardware reliability

Posted: Sat May 12, 2012 5:12 am
by tjc
Replacing the bad capacitors should bring the router back to life. It's a bother, and depending on your labor costs may not be worthwhile, but there are several threads in the forums about the specs for replacement caps and how to do it.

Re: RB750 hardware reliability

Posted: Mon May 14, 2012 11:46 am
by normis
I second what tjc said.
And yes, new models have either improved electrolytic capacitors, or solid state capacitors.