Belkin F5D7230-4 bad Teapo SM

[japlytic]

Today, I got a Belkin F5D7230-4 wireless access point, and upon opening it revealed that the DC (4.5V) input capacitor, a 1000uF/10V Teapo SM unit (C619) was bulging and was replaced with a 1000uF/16V Nippon Chemi-Con KY series unit.
There were two other Teapo SM series units after the linear regulator which were also replaced with 1000uF 6.3V 105C units (They were for the +3.3V rail).

Typically, I expect a switching regulator in newer networking equipment, but this model is an exception - +5V input to the +3.3V linear regulator would not cause excessive heat dissipation, considering the orignal input was +4.5V.

The two electrolytic capacitors near the linear regulator (input and first +3.3V filter) can get hot; this might be the cause of the input capacitor bulging.

[japlytic]

Re: Belkin F5D7230-4 bad Teapo SM

And here's the picture on the internals.

[Eagle2a]

Re: Belkin F5D7230-4 bad Teapo SM

Thanks japlytic. Coincidentally I was just looking inside the exact same model recently (F5D7230-4, v.6002) trying to figure out why the wireless function wasn't working. None of the caps were bulging but they all were Teapos except for the larger cap in the upper left hand corner of your photo (by the DC power jack) which was a Sanyo as I recall. I can't remember if Teapos were one of the caps reputed to fail without bulging. The router works fine connecting to the Internet and with the wired LAN connections, but the wireless function doesn't work at all. I'm debating whether to spend the time and effort replacing the caps even though they aren't bulging.

[shovenose]

Re: Belkin F5D7230-4 bad Teapo SM

if its wireless g then dont bother. i hate saying that, but when you can buy them for so cheap and wireless n is such an enormous improvement, its honstly the only thing to do.

edit: if you need a wireless g router, i have one i dont need, it was only used for a very short amount of time....pm me if you want.

[Eagle2a]

Re: Belkin F5D7230-4 bad Teapo SM

Correction: the Sanyo cap is located at the lower right corner of your pic. I didn't look at it carefully enough. BTW what are those 2 small black cylindrical devices with the 3 embedded wires? I don't recognize them.

@shovenose: this is an extra router I got from a friend. I have no need for wireless N either. How do you have over 800 posts since you registered in August?!? Are you adding that much value to this forum? O.o

[moddolicous]

Re: Belkin F5D7230-4 bad Teapo SM

Hey, sorry to bump this thread but I have a similar experience to Eagle2a. I have a Belkin F5d7230-4 v4000 router and the wireless does not work on it. Seeing as how it is a backup wireless router I thought it might be fun to have my first try at recapping a board. I was also thinking of getting a new / stronger antenna (maybe. If anyone has links that would be great).

@Eagle2a: Were you ever able to recap your board? Did it fix the wireless issue?

[Eagle2a]

Re: Belkin F5D7230-4 bad Teapo SM

@moddolicous:
Sorry I've been busy and didn't see your reply. I haven't gotten around to recapping it yet but I was planning to at least replace the cap by the wireless antenna (in the lower right corner of the photo) to see if it fixes the problem. I'll let you know how it goes when I do it, or please do the same if you get to it first. Thanks!

That's interesting that your router has the exact same problem. None of the caps are bulging but I suspect this router probably got overheated as the ventilation is quite poor.

[yyonline]

Re: Belkin F5D7230-4 bad Teapo SM

BTW what are those 2 small black cylindrical devices with the 3 embedded wires? I don't recognize them.

Those are ferrite beads. A sort of low-pass filter to reduce high frequency noise (interference mostly). You've probably seen them before as they come in a variety of shapes and sizes - all do the same thing more or less but can look drastically different.

Edit: based on a closer look at the picture, the ferrite bead in this case is likely a choke to reduce AC noise from the power input to prevent it from interfering with the wireless radio signal.

[jekkos]

Re: Belkin F5D7230-4 bad Teapo SM

Hello there,

A bit of a late reaction, but I do have such a Belkin_F5D7230 and flashed it with DDWrt. Yesterday I managed to break something by attaching an unregulated wall adapter with the wrong polarity. I found that the router was not completely dead, and that there is a component on the 4,5 track after the ferrit beads that has a voltage drop across it equal to almost the full applied input voltage. When I short circuit it, the lights of the router turn on, and sometimes it seems to manage to start up completely.

I have tried to find datasheets with the marked text on this green component (LF11/2A), but failed to find anything relevant. Does anybody know what component this exactly is? I suspect it is some kind of fuse, as it is rated with 2A, but I'm not quite sure.

Also, I found that the ferrit beads have some stuff underneath it. I saw it in the picture in this post, too, not sure if this is normal. Any ideas on this would be welcome.

Thanks!

[lti]

Re: Belkin F5D7230-4 bad Teapo SM

That looks like a fuse.