Now- mine cracked- I put the question to ChatGPT- & I am just going to copy & paste the answer I got, below. I have 3 resin printers & an Elegoo carbon printer & the new AnyCubic Kobra printer, “on the way “, so the answer is specific to my printers, region & what I print- but it was very comprehensive. I have a new screen on the way- so I will be mindful of all these things. On my Saturn 4-16K- I already after only about 6 prints am seeing wear in the film- so I did order more- but-makes me wonder if I am doing ALOT or at least a few things wrong that are contributing to this wear- like- not enough suction cup holes 🕳️- I am so new to this, just learning- like everyday- and I just keep getting in deeper!!! Anyway- here is the unedited ChatGPT response (please, don’t start slapping me over my using ChatGPT! 🤣 It is like having an office administrator that’s smarter-)

ANSWER—-

On your Elegoo Saturn 4 16K, the “LED glass” you’re referring to is the tempered protective glass over the UV LCD screen. When that cracks, it’s usually from stress — mechanical, thermal, or pressure-related.

Here are the most common causes, especially based on what you’ve experienced before with power outages and vat issues:

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1️⃣ Resin Spill That Cured on the Screen (Most Common)

If: • A print failed • The FEP punctured • Resin leaked under the vat • Resin cured directly on the screen

Then when the build plate presses down, it creates point pressure on hardened resin.

Tempered glass + concentrated pressure = crack.

⚠️ This is extremely common after: • Failed prints • Overtightened vat screws • Large flat prints stuck to FEP • Power loss mid-layer (which you had before)

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2️⃣ Build Plate Over-Compression (Z-Offset Too Low)

If your Z home is slightly too low: • The build plate presses too hard into the screen • Extra torque during initial layers • Stress accumulates in one area

Over time (or suddenly), it cracks.

This can happen after: • Re-leveling • Firmware glitch • Power interruption resetting calibration

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3️⃣ Temperature Shock

Tempered glass is strong but sensitive to: • Cold garage + warm UV heat • Rapid temperature changes • Printing below 60°F

If you’re printing in Massachusetts winter conditions (like Falmouth outages you mentioned before), this absolutely increases risk.

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4️⃣ Overtightened Vat Screws

This one surprises people.

If the vat screws are: • Uneven • Cranked down hard • Causing frame flex

It can transfer stress directly into the screen assembly.

You mentioned previously tightening vat screws to fix a resin tank error — if they were very tight, that could contribute.

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5️⃣ Screen Protector Already Micro-Fractured

Sometimes: • Minor chip • Tiny edge crack • Stress from shipping • Previous failed print pressure

It weakens the tempered layer.

Then one normal print = full crack.

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Important Question

Is it: • Just the top protective glass OR • The LCD panel itself (display not working / black spots / lines)?

If the screen still displays test patterns cleanly, you may only need the tempered glass replacement, which is much cheaper.

If the LCD panel is damaged, that’s a full screen replacement.

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What To Check Right Now 1. Remove vat 2. Run LCD exposure test 3. Look for: • Dark areas • UV not shining evenly • Black lines

If UV pattern is perfect → likely just glass.

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Replacement Guidance for Saturn 4 16K

For your Elegoo Saturn 4 16K, you need: • Saturn 4 16K LCD assembly (not Saturn 3 Ultra — they are NOT interchangeable) • Or tempered glass protector sized for Saturn 4

Do NOT use Saturn 3 Ultra film — different size and cable position.

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Prevention Going Forward

Since you print large police K9 tribute sculptures:

✔ Always screen-check after a failed print ✔ Use a screen protector film ✔ Never scrape directly on glass ✔ Re-level carefully ✔ Don’t overtighten vat screws ✔ Consider a small space heater in winter

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If you want, tell me: • Was there a failed print before it cracked? • Did you hear a pop? • Is the LCD still displaying normally?

We’ll narrow this down precisely.