RTL dongle repair

[thewraith2008]

I noticed a few months back that one of my blue RTL SDRs (RTL2832U+R820T2) had died.

I have a bunch of these dongles and you used to be able to get them for under $10.
With a little bit of shielding in select locations (not shown in image) and the addition of a TCXO (at the time I did them, they were about $4), these worked quite well.

Been curious, I wanted to see if I could locate where the fault was.
Turns out, the internal 1.2v switching regulator in the RTL2832U had died. There was no 1.2v present.
The switching regulator requires some external components to function. This voltage (1.2v) is then returned back in to the RTL2832U via a few different pins.

As a test, I wired up a LM317 regulator to output 1.2v and connected to the RTL2832U. (see image)

• I removed the 4.7uh inductor first to isolate it from the RTL2832U switching output.
• You should also isolate pin 27 and connect it to GND to disable the internal switching regulator (I didn't do this, to fiddly and it wasn't working anyway).

Looks ugly, but the dongle now works as expected.

Hope this is useful to someone who likes to try and fix things.

 

[APX7500X2]

Well, that's impressive!

I'll stick with paying $30 to replace it. if I tried that the house would probably catch fire LOL

 

[nexusjuan]

Well, that's impressive!

I'll stick with paying $30 to replace it. if I tried that the house would probably catch fire LOL

I have electronic projects in my house that give me this same anxiety and they aren't nearly that ugly. This model can still be found in the 12ish dollar range from the usual Chinese source. I upgraded and got one of the msi.sdr sdrplay rsp1 that go from 10hz-2ghz for $16. I'm loving it can display 8-10mhz at a time versus the usual 2.4

 

[merlin]

Nice if you like to tinker.
One of my dongles died from electrostatic discharge (there is a fix for that). Thunder boomies.
Took out the preamp stage in the tuner IC. Not worth the fix replacing the 2832U.
Bought a replacement and after the discgarge fix, still runnung fine.
First one did run quite hot. Attatched a heat sink, that helped.
The new replacement gets warm, but not scary hot. Ha better frequency range too.
The blog v4 is out, that is on my get list. Nice companion to my Airspy HF+ discovery.