[German]Initially, a German blog reader contacted me and reported that his FRITZ!Box 7590 router from the manufacturer AVM suddenly had a defective 2.4 GHz WLAN. After doing some research, it turned out that many owners are confronted with similar behavior. The FRITZ!Box 7590 introduced in 2017 suffers from a dying 2.4 GHz WLAN. AVM will replace the FRITZ!Box within the 5-year warranty period. Here are a few details.
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A reader reported a broken FRITZ!Box 7590
The FRITZ!Box 7590 router from German vendor AVM is suitable for VDSL connections up to a speed of 300 MBit/s. The device enables WLAN up to 1,733 and 800 MBit/s and supports up to 6 DECT cordless telephones including answering machine. The box also has 4 x Gigabit LAN, 1 x Gigabit WAN and 2 x USB 3.0 ports.
FRITZ!Box: Source AVM
There are a lot of FRITZ!Box 7590 devices in use – the device is also still receiving firmware updates. A couple of weeks ago, German blog reader Michael contacted me by e-mail because he noticed a failure of his FRITZ!Box router. According to the reader, he came back from vacation and found that the 2.4 GHz WLAN was dead. Since his FRITZ!Box is from 2018, any vendor warranty (in Germany 5 years for end users) has of course expired and one would be inclined to think "it's an isolated case, that's just the way it is".
The date of manufacture of a FRITZ!Box can be determined using the serial number. According to this German article, the first four digits indicate this date. The decoding of the digits is possible via this German article.
Many similar reports
After a Google search it became clear, that there are more similar cases reported by other FRITZ!Box 7590 owners. In German IP-Phone forum, for example, there is the thread FritzBox 7590 2,4GHz WLAN nur noch sehr sehr schwach from March 2023, where someone complains that their Fritze 7590 no longer provides 2.4Ghz WLAN. The signal there is very weak and the device from 2017 is out of warranty. The person concerned suspected a hardware problem on the relevant transmitter side. The thread in question mentions several times that other users with similar problems have appeared in the forum.
Also on German site mydealz.de there is the discussion thread FRITZBOX kein 2,4 GHz wlan mehr from April 2023, where the topic of 2.4Ghz WLAN failure is addressed. There is no more WLAN in the 2.4 GHz range. Also in this thread other affected persons confirm the failure of the 2.4Ghz WLAN. If you are still within the manufacturer's 5-year warranty period, the FRITZ!Box will be replaced.
A search on the Internet turns up further hits – interested readers will find a more extended link list within my German edition of this blog post. I found also the reddit.com thread [FRITZ!Box – 7590] 2.4 Wifi Network doesn't show on any device with a similar description. The hints given at this AVM support site doesn't help.
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It looks as if more and more devices with failed WLAN in the 2.4 GHz range have been appearing in recent months. This raises the question for the reader as to whether the failure of the 2.4 GHz WLAN module is a serial defect or even planned obsolescence? If I compare the presumed number of many thousands of FRITZ!Box 7590 devices with the number of failures that I found during my Internet research, I do not assume that there is a major quality problem. But there are these failures and it is not an isolated case.
I contacted the vendor and have received feedback from a AVM speaker with the following information. A larger number of failures is not known – therefore the manufacturer rules out a quality problem. I am currently unable to assess how the failure rate relates to the failure rate of the components.
The cause of the failure
A defective voltage converter IC (MP1477) or the component 055F has been identifies as a root cause. On German site mikrocontroller.net the topic is discussed in this thread. And in the IP-Phone forum, posts #80, #110 and #144 in this thread also refer to this defect.
Broken FRITZ!Box 7590 2.4 GHz WLAN component, source: Screenshot mosfetkiller.de forum
Blog reader Martin P. sent me the following photo of his defective circuit board and permission to use the photo (thanks for that). You can see that the IC AUCH 289 and a neighboring SMD resistor (or SMD capacitor, see) are probably burnt out.
Broken FRITZ!Box 7590 2.4 GHz WLAN component, source: Martin P.
If you are outside the AVM 5-year warranty, there is this post in the mosfetkiller.de forum in which someone has discussed the broken component (voltage converter). I'm now in contact with a German guy, who tries to repair this burnt up components. But this isn't an option for users in foreign countries I guess.
A short-term workaround
If you need the 2.4 GHz WLAN but your FRITZ!Box breaks down outside of AVM's 5-year voluntary warranty, there is a short-term workaround. As a cheap emergency measure, if the function is urgently needed, it is possible to use an AVM repeater for the FRITZ!Box to pair the devices via the 5 MHz channel and have the repeater provide the 2.4 GHz WLAN.
Important: However, you should bear in mind that other components in the router can break over time. First, most users can hear a high frequency noise, then the 2.4 GHz gets weak and a while later, this WLAN is broken. Over time, also the 5 MHz WLAN will show the same behavior, and then the FRITZ!Box 7590 can't boot anymore. And there ist also a risk of fire (although the probability isn't too high). I would therefore take the device out of service immediately and have it repaired or replaced.
I will give more details in a follow up article.
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Many of them are currently crashing with various WLAN problems. The same goes for the 1750 repeaters from the same period.
After 5 years, this would simply be a question of money and therefore manageable in the vast majority of cases. However, the lack of S0, with successor models available on the market at normal prices, makes the whole thing less relaxed!
The investment can easily run into 4 figures if the intact and immortal ISDN gadgetry has to be replaced, which in the vast majority of cases would easily be good for another 10 years and fulfill all user requirements.
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