In our last batch of RB411 we have had about a 20% (4 out of 15) failure rate. Looks to be the power supply, several of them made it past the initial config load and in to the field when plugged in. The radios were replace and the new ones are working fine. The power supply LED was flashing indicating a short.
Testing on the bench with through the power plug (as apposed to POE) promptly smokes a tiny chip in the PS. I don’t think it is a design issues as we have lot to these boards out there. Could be a production or component problem.
Anyone else seen any similar issues. I’m hoping this small batch of board is an anomaly, I won’t see again.
sadly yes… It seemed to be the last production batch affected. We don’t have 20% but at the moment roundabout 10% of the last shipment. Next week we get new in, hope they are better.
Which cap… they all looked fine, when I hooked it up to a PS (60 amp) the small surface mount chip (Q801) went up like a small nuke.
I have just lost another couple, did a remote software upgrade and it never came back, not sure it is the exact problem as this one (and 2 other) exhibit a slightly different problem. There is no indication of a short but the board does not complete the boot process. I will be checking the voltages and and hooking up a serial cable to one this week to see what I can find.
Any how that is now 5 out out to 15 boards or 33% failure with a few days of deployment. We have a large order coming in , I hope it don’t see any of these issues with the new batch.
We have a stack of 411’s (~10) that have the same problem. I also have 2 RB433s and a RB433AH that have the same problem. I was able to bring the 433AH back to life by removing C801. It looked slightly different from the other cap right next to it. I was also able to remove the same cap from a different position(I don’t have a 411 in front of me) on a RB411 and have it start working again .
I didn’t try on the other 433’s or 411’s since I didn’t want to void the warranty..
@ejansson
I’ve seen a bunch of RB411’s with that Q801 chip damaged after lightning storms.. It seems to be the first to go..
The caps we have had a few problems with on the rb411 are c802 & c825.
As far as letting out the magic puff of smoke from an IC; I think it’s a gonner.
I hope this is just a bad batch of caps. All my problems have been solely with the last order. Out of the units you’ve seen go, have they been recent purchases or have they been in the field for some time? We have a good number out there and so far have not seen any issues.
Most we notice before install or within the first week.
Only a small handful 5 or 6.
We had one where the CAP lit up like an LED.
Could have sworn at first glance it was an LED until it bacame dim 30 or so seconds later.
We removed the cap and everything is fine, so we replaced it with another we had lurking around.
Helps to have a reverse engineering background.
Although this fix did not require expertise.
Thanks, sound like the same thing. Just a bit worried about the others in the field, but sound like they will most likely be OK. I’ll get out the soldering gear and see if I can fix the 2 non smoking boards!
I have one sitting in front of me with this problem. It quit working when I installed it with POE, so I took it back to the office and plugged it in directly and c825 smoked. I was told by my reseller that they don’t warranty Mikrotik products. It is our responsibility to send them back to Latvia. Hardly worth the cost of shipping I imagine.
I guess if my distributor won’t do a warranty, and I can’t warranty them directly, then there is no warranty. I guess I need a different distributor or they are just throwaways.
The company I am working for just bought $10 000 worth of routerboards for a wireless network to be installed at a game lodge. A friend started the configuring of the wlan in the office and all went fine. However when I got into the field I was shocked to blow two boards in two days.
All boards are getting powered with two 102AmpHour batteries which are charged during the day by solar panels.
I have a system of testing all connections before I connect to a routerboard:
I keep a senao client bridge with me and just prior to hooking the power into the power jack I test that the bridge boots.
I take a voltage meter and test for polarity and voltage amount.
In the first case the voltage was 13.2 volts - I plugged in the router and nothing happened. No lights, no sound. I plugged it out and in again and a chip on the board close to the power jack popped. The board had been lying on a plastic lid in the sun for about 10 minutes and was quite warm to the touch.
In the second case having blown a board the previous day I confirmed with the guy with me that the power was correctly setup. We checked for polarity, agreed that positive is on the inside of the jack, hooked up a client bridge which booted fine and worked. Plugged it in and within 2 seconds smoke started coming from the board.
Looking at the board I see chip Q801 has a burn mark on it.
I have to admit I am really happy the boards are still working (the first one on the ethernet jack) and the second with a normal power supply on the power jack so the project can continue… but it just unnacceptable that this kind of thing happens on two out of the 5 boards I have used in the field this week.
I am nervous about connecting any more to batteries as I am sure my supplier (miro in south Africa) is goingto swop out the board.
If I was unsure I would say fine. Maybe I made a mistake… but as a result of the first board blowing I was VERY careful and still had this happen. Clearly the boards are faulty!
Both boards are 433’s. The first one blew D802 and I mentioned the second one blew Q801.
Serial number on the second one is: 1A7501F05D83/840
Most of mine that lost POE still work on the power jack. It is sometimes easier to run a power cable that bother with sending the boards back and forth. Of course, they shouldn’t have fried in the first place.
I have the same problem on one of my 433AH,
they are crap in this sense, if there is a short interruption of
power they they wont come back alive until you turn them off
for 60 second to discharge the capacitors.
whats the part number for this Q801? I want to purchase a replacement
and replace it myself.
This is a well known problem that was addressed and fixed last year.
In the RB433/AH you must change capacitor C828 to: ceramic capacitor, type 0805, 1uF
See this thread: http://forum.routerboard.com/viewtopic.php?f=3&t=3868
It is a really small 805 series capacitor and requires good smd (surface mount device) rework skills and smd equipment.
We have been testing samples of our new RB4xx inventory as it comes in and Mikrotik has not sent us any boards with the old cap values since last December.
I was looking forward to order quite a few of these now I’m somewhat hesitant. What are mikrotik US warranty procedures if one ends up with a dud? Do I send it back to to you? Who pays for shipping?