Shruthi LCD showing 2 lines of blocks

This is happening. I don’t know what to do next, help please!!!

A defect or bad soldering joint on the contrast trimmer.

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I just tried removing contrast trimmer and soldering a new one and nothing changed. It is the 5k, right?

Any suggestions…? I don’t know what to do

Not enough information.
Did the Shruthi ever work? Firmware installed?

I installed the firmware in other empty shruthi (verified that worked), removed atmega644 and eeprom and then put them into this one. That means yes, it’s installed.
First time turning on this device so no way to know if it’s working
Thanks for replying

Do the LEDs react to button presses? In your picture I see all LEDs are on. This and the display indicate a microcontroller problem. Try to reseat it (maybe bad contact). Or change it back to your working shruthi to verify it‘s really still ok.

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Another idea: could also be short under the LCD. Try to look under the display that nothing from the controller board has contact to the underside of the display.


Thanks! I will try that and see!

Did you try adjusting the contrast trimmer? Adjust fully left, then all the way right again until the contrast is lowered and the text is readable.

I already did that. Fully left until nothing appears and then fully right and the blocks come back again. I will try reprogramming flash these next days and see if it works. Thanks though

This really looks like a damaged LCD screen.

Note that if the MCU isn’t working (generally: if the LCD doesn’t receive an initialization command from the CPU), you usually see only the first line.

What bothers me is that all LEDs are lit on the Shruthi - that’s quite strange too.


Hmm… I just changed LCD and still the same…

Ok now I reprogrammed the chips and still… nothing happened

Ok, I am asking again: do the LEDs react to button presses?

Show us pictures from both sides of the controll board in high quality.

Oh sorry. No, they do not react.

Soldering looks good. But why are the leads from the LEDs so long? Maybe they short something on the filterboard? Cut them as short as possible.
And generally look that nothing from the filterboard is touching the controll board when connected.

Ok. It was just in case the values of resistances were incorrect for those colors, it’s easier to unsolder leds i think. But it turned out great so I’ll cut the legs and let’s hope it’s that

I just cut the leads and nothing happened… any clue?? :sob::sob: