Saturn 4 Ultra 16K: the LCD shows no image, a partial image, lines or dead pixels, and how to replace it
Guide based on the manufacturer's official documentation; usi3d has not yet verified it on a machine.
Technology: Resin · Brand: Elegoo · Symptoms: The LCD screen or UV light does not light up · Updated on 10 October 2026
Symptom
In the Saturn 4 Ultra 16K exposure test the LCD stays black, with the UV light on or off, shows only part of the image, has dead pixels, flickers or shows lines.
Likely causes, from most to least likely
- The LCD has dead pixels, cracks or other damage.
- Leaked resin, cured resin or dirt on the LCD or on the Fresnel lens blocking the light.
- The LCD cable is badly fitted, makes poor contact or is damaged.
- The firmware is outdated or incompatible.
- The LCD itself has failed.
Checks to tell which one it is
- Run the exposure test in «Tool» → «Exposure» → «ELEGOO»: the Elegoo logo must display completely and properly.
- With the LCD not exposing, look for cracks and for cured resin, dust or dirt on the LCD or the Fresnel lens.
- If the LCD shows the image but the UV light does not come on, the fault is in the UV light, not the LCD.
Before you start
Uncured resin irritates skin and eyes: wear nitrile gloves and safety glasses, ventilate the room and do not look at the UV light. Before taking anything apart or cleaning it, switch the printer off and unplug it, unless a step says otherwise. If in any doubt, stop and ask a professional.
Step-by-step fix
Check the LCD surface
With the LCD not exposing, look for cracks: if there are cracks and dead pixels, replace the LCD as soon as possible. If not, clean cured resin or dirt off the LCD and the Fresnel lens. For cured resin, wearing gloves: alcohol-soaked swab around it, wait about 5 minutes and use a scraper, only on screens with a tempered glass film.
Check: The exposure test shows the whole logo.
If that does not fix it: Check the LCD cable (next step).
Reconnect the cable at the mainboard
Turn off the power switch and unplug. Remove the back cover (7 screws, 2.0 mm Allen key), remove the tape holding the LCD ribbon cable, lift the latch, unplug the cable and plug it back in firmly. Check the cable for damage.
Check: The exposure test shows the logo properly.
If that does not fix it: Check the other end of the cable (next step).
Check the cable at the LCD end
To reach the other end you have to take the printer apart as in Elegoo's LCD replacement guide. Check that the cable is fitted correctly and reconnect it. If the cable is marked, the «LCD» or «SCREEN» side faces the LCD and the «MB» side faces the mainboard. If it is damaged, switch off, unplug and replace it with a new one.
Check: The LCD displays the image again.
If that does not fix it: Update the firmware (next step).
Update the firmware
If the cable and the LCD show no visible damage, update the firmware to the latest version, from Elegoo's download centre or by OTA if it is not listed there, and repeat the exposure test.
Check: The LCD displays the logo properly.
If that does not fix it: Replace the LCD (next step) or ask Elegoo support first.
Replace the LCD (A0S0V1)
Switch off and unplug. Elegoo's guide for the 16K involves removing the back cover, the UV light enclosure, the side and front covers and the base (14 screws), peeling the tape at the LCD edge, removing the Fresnel lens (10 screws, without touching it with bare hands) and pushing the LCD forward to take it out. The new one goes glass side down, with double-sided tape on the frame.
Check: In «Tool» → «Exposure» → «ELEGOO» the logo displays properly: the replacement is done.
If that does not fix it: Contact Elegoo support (next step).
Information for Elegoo support
If the LCD still shows no image, send Elegoo support photos of the LCD when not exposing and while exposing, of the cable connections at the mainboard and at the LCD, of the QR code on the LCD side, and the order number (or the invoice if you bought it from a distributor).
Check: Support tells you what to replace.
If that does not fix it: Bear in mind that, according to Elegoo, the LCD warranty does not cover resin leaks, damage to the scratch-resistant film or impacts.
Prevention
- Filter the resin before every print.
- Use the tank cleaning function after every failed print.
- If you find cured resin on the LCD, check the film: it usually comes from a tank leak.
Still not fixed?
Tell usi3d's AI about your case: choose your printer, describe what you see and add photos if you like. It proposes checks step by step, with their sources.
Printers it applies to
Elegoo Saturn 4 Ultra 16K.
Official sources
This guide summarises the official documentation linked here:
This guide is general information: usi3d has summarised it from the official documentation linked here, and it may not match your model, its version or its firmware. If in doubt, follow the manual and the support of your printer's manufacturer. You decide what you do with your machine, and working on it may affect its warranty.