Hobby electronics dies

hobbyelektronik.org blog

After the last very hot weeks there was finally a cooling off.

Not only humans and animals suffer from the heat, but also electronics. One of the candidates we see again and again is the Fritz! Boxes, which die in heat after 2-3 years. If this happens in the first 5 years after purchase: no problem - AVM has a very good warranty service that eliminates the problem almost free of charge (you only have to pay for shipping to Berlin). After that you are on your own. For most, it ends up buying a new device. For someone who knows how to solder, you can lend a hand for a few euros. On the thing, old electrolytic capacitors out, new ones in.

This is also the case with my parents' box. At first WLAN became a bit unstable, then the UI became unusable - luckily the phone (WAF) remained stable for a relatively long time. At some point the part ended up on the workbench. Here is an overview of the built-in potential culprits:

I consider the values ​​in bold to be in need of replacement, as they are attached directly to the switching converters. With the others I cannot say with complete certainty - at least I consider the 47 µF / 25 V at the top of the USB socket to be a good candidate, as well as the 47 µF / 63 V at the bottom right. As far as you can see, the other 100 µF are connected to a linear regulator and don't see that much ripple. All just a rough estimate, of course, a more detailed circuit analysis (or a thermal imaging camera) would provide more information.

Anyway, here is a list of the built-in types and possible order names at Reichelt.

quantityC [µF]U [V]T [° C]D [mm]RM [mm]Reichelt order name
2100016105105RAD FC 1,000 / 16
1100251056,32,5RAD FC 100/25
2472510552,5RAD FC 47/25
11001010552,5RAD FC 100/10
21001610552,5RAD FC 100/16
31010010552,5RAD 10/100
147631056,32,5RAD FC 47/63
14,710010552,5RAD 105 4.7 / 100

In addition, I have given the device what AVM has consistently forgotten to incorporate over the past few years:

This should at least eliminate the thermal bottlenecks for the next few years.

Since a 7390 who died of overvoltage is still floating around somewhere, the next few days [tm] there will be a picture + data for this model.

Update 03/18/2019: In an earlier version the order name was "PAN FC [...]" which is of course wrong. Many thanks to Raphael for pointing this out.
NB: Which madman at Reichelt has created the new order names for the electrolytic capacitors?

This entry was posted in Electronics, Disassembled and tagged AVM, Elkos, Fritz! Box, Hardware, Hitzetod, Internet, Router, Telekommunikation by Chris. Permanent link to the entry.