RPI3 Heat Sinks on Limesdr-mini

It is likely that you have caused unrecoverable damage to your board. But there is a small chance that only the FPGA configuration suffered, that’s why i suggested to reprogram it manually - and for that you need to use the USB-Blaster.

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ok im gonna order one off amazon.

do you think this will be compatible?

what makes you think what i did makes the board unrecoverable?
i can still talk to it with LimeUtil --find and SoapySDRUtil --find
even Limesuitegui will connect to it. i can “Read Temp” and "[17:20:08] INFO: Connected Control port: UNKNOWN FW:0 HW:0 Protocol:0 GW:0.0 Ref Clk: -0.00 MHz
“.
it is in some kind of a loop in limesuitegui because if i click a “button” like Read Temp” it takes a certain amount of time to actually execute it. when it gets to a certain point in the loop and it tries to execute the “button” command and usually replies with “[17:20:08] ERROR: Read(64 bytes) failed”

No LED lights on board show up no matter what.

if board is broken what part you think it is?
LM7 chip?

@en1gma
In the following post it was the FX3 chip that needed to be reworked: LimeSDR-USB gateware version is not recognizeable (temperature related)

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Actually, you should start by measuring the board voltages. There are test points on the board labeled VCC3P3 and VCC1P8.

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Awesome.
im descent with a volt meter.
can you link me to where the info is to the test points and voltage they should be and hopefully isolate the problem down to the area if a test point isnt measuring what it should be.
thanks

Here is the PCB drawing: LimeSDR_Mini_1v2_PCB_Drawings_r1.PDF
here is the schematic: LimeSDR_Mini_1v2_schematic_r1.PDF

But this version from the Wiki is a bit more readable:

image
image

IC12 IC Switching regulator (1.8V)
IC13 IC Switching regulator (3.3V)
IC14 IC Linear regulator (2.5V)
IC15 IC Linear regulator (12.5V)
IC16 IC Linear regulator (1.4V)
https://wiki.myriadrf.org/LimeSDR-Mini_v1.2_hardware_description
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mine says its hardware v1.1
should the voltages be the same as listed above?

IC 15 and IC 16 aren’t in the same place between the v1.1 and the v1.2 PCB.
Here is the PCB drawing: LimeSDR_Mini_1v1_PCB_Drawings_r0.PDF
here is the schematic: LimeSDR_Mini_1v1_schematic_r1.PDF

Which makes testing the voltage rails even easier. LimeSDR-Mini v1.1 has 1.8V, 3.3V and 2.5V. The 1.8V and 3.3V test points are labeled on the board. The 2.5V is relabeled as VDIO_LMS_FPGA and VDIO_LMS on the schematic; the FPGA and the LMS7002M and the LMS EEPROM all connect to 2.5V.

great info! thanks very much,
will be checking this out later tonight as i got a lil work to do right now.
hope my board isnt fried.
was really learning alot about RF.
was just about ready to schedule a technician test.
:frowning:

i could find 5.0v, 3.3v, 2.5v but i dont think i can get 1.8v
could you tell me where to put my leads to my volt meter?
if the voltage regulator for 1.8v isnt working what are my options?

Look at the holes in the board labeled FPGA JTAG. 1.8V should be second from the right.

thats what i was afraid of.
the 1.8v on edge connector holes on top and bottom show .14v or something
i think on the edge that has the most holes the 1.8v is next to the 5v and the opposie side the 1.8v is next to the 3.3v

if those are supposed to be 1.8v while connected to a computers usb 3.0 port they ate not.
i get .14v

the altera chip programmer wont help me?

the altera chip programmer wont help me?

I dont think so…:frowning:

So, two possible problems now:

  1. The 1.8V regulator is broken, thus not providing enough current
  2. Something feeding from 1.8V is broken

You could do some debugging to find out, but this now involves soldering off components and/or breaking the PCB rails. Another option would be to blindly replace the 1.8V regulator.
But i guess a cheapest way (if you count the work hours) is to just buy a new Mini.

crowdsupply cant fix?

No, there isn’t a repair service, as it wouldn’t prove cost effective with a board using this sort of technology.

what about warranty?
i dont think i did anything un usual to break the 1.8v voltage regulator

looks like i might have found the problem.
in the picture its the voltage regulator on the left.
a capacitator came off.
i found the cap.
not sure how to solder it on

THat (I think) is a DC to DC converter module. It may need to be completely replaced. Look it up in the BOM file & Mouser & the like probably have it.
Please go to a circuit board company for repairs. If not, find someone local that is experienced in SMD rework. Otherwise, you run the risk of messing up the copper traces. Trust me, it is not for the inexperienced.

Ed

https://www.mouser.com/ProductDetail/Murata-Electronics/LXDC55KAAA-205?qs=Jp4yxA3Y%2FLwvww1X62uIsQ%3D%3D

THat’s the part on Mouser. Get a couple, as they are listed as “End of Life”.

Ed

thanks for the info.
cant i just solder the cap that came off?
if i order a couple of the converters can i remove one of its cap’s and put them on my board thats still on the mini?
would be great to just order the missing caps