the last two months i had 5 rb450 with the same problem. It stops to work , and them the eth4 and eth5 leds turns on a very weak light. All these RB450 had been working for about 8 to 10 months.. when opened, i found ttwo capacitors leaked and blowed ( su’scom 560uf 6.3 volts..) I just bought about 50 rb450g and found out that they have the same capacitors… should i be worried?? is this a known issue? the problem is the lost of reliability .
I’ve had 20 RB450s with blown capacitors. The reseller has been successful in replacing some, the others I’ve just gone out and bought the 6.3v capacitor (I upgraded to 680uf) and soldered them in myself. You’ll need 3 per board.
I’ll have to try to find a board that I haven’t repaired yet. However I can point out the capacitors I had to replace in order to make the board operational again.
I purchased 20 RB450s in 2008 from Tom at Roc-Noc. During 2009, each of the 20 failed. Tom mentioned that Mikrotik was aware of the capacitor issue and would offer a replacement of the 20 RB450s. In that time I’ve received a partial replacement. Sadly, due to the substantial delay in receiving the remainder of the RB450 replacements I’ve had to implement my own repairs, replacing the 3 capacitors in the picture below.
If your RB450 fails, you will see 3 bulging and brown capacitors in the areas I’ve pointed out below. Replace those and your RB450 will be functional again as well as not having the issue where a rapid power outage will cause the board not to reboot.
The three brown capacitors in the picture I uploaded are the replacement caps I purchased locally. Tom at Roc Noc may be able to take a picture as he has several blown RB450s on his hands.
I’ve got the same problem, here’s some photos of the bad caps
My RB450 has been in continuous use for about 1.5 years now. It was also probably running a bit hotter than it should have been (sitting on top of a Linksys AP that throws of a lot of heat).
I’ll probably just resolder some new caps, as I always like an opportunity to bust out my Weller.
If you can make it fit, try to get caps for a higher voltage instead of higher capacity. It could be that the original ones are a bad batch but so many?? may be at a higher voltage they never fail again.
The trouble is that for a higher voltage they are bigger, so take the board to the electronics shop to see if they fit before you buy.
EDIT: just to be sure, measure the voltage over the capacitors while the board is turned on… you should see a DC voltage. Check if the polarity is right and how high that voltage is. Now you know if the caps have a too low voltage rating and if they are mounted at the right polarity!!
They were swapping mail boards like crazy…
I had a pair of 270 small form factor units affected…
Intel, acer, and just about everyone has had there share of them…
We call them " Jiffypop " caps…
Swap them out with higher qualtiy caps and all is well.. ( If the unit hasent been run too long and damaged the power circuit..)
Keep the values the same ( Voltage can be a bit higher )..
Cap “values” “CAN” be critical… if it is a passive filter cap then not so much,
If it is part of a “charge pump” circuit then it can be very critical… (Can affect output voltage or load on charge pump voltage controler)
Change out sould only take about 3 - 5 Min each… An experianced tech with a bit of practice can do them all in about 5 Min..
I just had this happen to a RB450G I own. Here are the pics:
I will have had the unit for a year next week. I bought it from rocnoc.com, so hopefully they can repair/replace it for me. Otherwise I’m going to have to learn to do some soldering I guess. I’m not very happy about this
when opened, i found ttwo capacitors leaked and blowed ( su’scom 560uf 6.3 volts..) I just bought about 50 rb450g and found out that they have the same capacitors… should i be worried?? is this a known issue? the problem is the lost of reliability 
