Velo 1 4MB LCD bizarrity

Anyone seen the LCD offset on a Velo 1 as pictured? Any help with recommended fix ideas which I may try?





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As pictured where?

Took me several iterations to get the file size below 100kb with my phone software!

Now there's a novelty. I'm kinda reminded of the one time my TinyBook T706 booted with the display upside-down and backwards (ie, a mirror reflection from the top). Never did figure out how that happened.

I'm assuming a hard reset didn't cure it.

Certainly a novelty! Your experience moreso than this one! Touchscreen is calibrated properly, upper left corner tap will bring forth the menu in the middle of the screen under file.

No dice on hard reset. Today's Easter and I don't have the small torx screwdriver required to check about the LCD flex cable inside. Some places seem open, but doubtful on the little local hw shops or Sears are.

Wonder if it's an Easter egg from the OEM. (Sorry, couldn't resist.)

Clearly a hardware problem. The cable is the first thing that comes to my mind.

Absolutely my first guess as well...the ribbon cable is not securely seated for the LCD...however, how does the touchscreen respond? Is it independent of the LCD image as it should be, or is it coordinated with the image?

He answered that question in his last post, Rich.

Touchscreen is proper. Clicking on the areas where controls would be if image was left justified hits them properly. Sears was open and now I'm an owner of their last T5 torx screwdriver that was on the floor.

That's the weirdest problem I've seen here for a while. For the matrix to be cleanly offset though? It would have to be a clock skew issue surely. .. For the parallel pin out to be wrong... ?

If it were a damaged ribbon you'd expect the area to be missing rather than offset. So my money is some sort of clock skew and the data from the frame buffer is now arriving late in the clock cycle to the screen controller in front of the lcd matrix.

Why that's happened? Blown buffer register? Change in resistance across the fpcb?

C:Amie, I think you're on to something there.

I opened it, the LCD ribbon was securely seated. In the attached image, you can see some degradation of the contacts. I wiped it clean with qtips and solvents. I noticed the AA battery area nearby had suffered some corrosion, likely due to battery leakage before. I wiped down all that area also with the solvent and QTips. Dried it off, blowed compressed air over it to remove artifacts, and reseated the flex cable. Afterwards, I reassembled and observed the same skewed LCD offset as prior to the disassembly and cleaning.

Your analysis is the most cause, paired with the obvious corrosion from battery leakage as the root cause. Though I can not eliminate the flex cable entirely, attached image magnified 30x loupe will show why due to the corrosion of the contacts.





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Can you get to the terminals on the other end? If so, you can run a simple resistance test across all of the pairs.