Replacing the Internal Power Supply for Epson ET-4750: What You Need to Know

Question:

I have an Epson ET-4750 that needs an internal power supply (ST-4000 3-prong plug). Do you have one for sale that you can sell me? Would a 2-prong power supply be suitable for replacing this model?

Answer:

Power Supply, Epson ET-4750

(We have a compatible internal power supply for the Epson ET-4750 and ET-15000 printers.) You can find it here:

Epson Power Supply for ET-4750 & ET-15000 (https://bchtechnologies.com/products/epson-power-supply-for-et-4750-et-15000-no-return?_pos=6&_sid=c9cd8cc19&_ss=r)

But before you shell out cash for a replacement, you must determine if the power supply is the problem. Not all printers that don't switch on mean their power supply has gone bad.

You’re working on a new sample with an upgraded internal sensor.

Check the voltage output of the power supply before assuming it’s defective:

Use the multimeter to measure the output voltage.

Output is supposed to be 42V and between 1.3V to 1.5V on the secondary circuit.

If the power supply is outputting the voltage it should, the problem is likely not the power supply, but a fault on the printer’s mainboard or some other internal component.

We do NOT accept returns on this product, because this is an issue that many users will purchase a new power supply without having tested their original unit, and we do not want to impact customers who realize the problem was elsewhere with their next purchase, and return this item.

Does a 2-Prong Power Supply Work on an ET-4750?

A 2-prong power supply will not work or fit in the Epson ET-4750. This is a 3-prong power cable specifically for the ST-4000 printer model. If you try to use a different type of power supply, it could cause:

Power input mismatched with the printer.

Not having enough power leads to operational failure.

Possible electrical damage to the internal components of the printer.

Suppose the printer does not power on after replacing the power supply. In that case, the next step is to move on from the power supply and troubleshoot the mainboard or internal fuse circuits to see if an electrical failure occurred.

Next Steps:

You can also test your existing power supply with a multimeter before purchasing.

If the voltage output is incorrect, order the correct 3-prong power supply (https://bchtechnologies.com/products/epson-power-supply-for-et-4750-et-15000-no-return?_pos=6&_sid=c9cd8cc19&_ss=r).

If the power to the unit is getting through but still will not turn on, we will need to check the mainboard for a potential fault.

This printer model is not compatible with a 2-prong power supply.

Printer power problems are complex to address because diagnosing internal components is challenging. We cannot troubleshoot remotely or provide support for power-related printer repair. We will never, however, edit or try to manipulate your printer remotely, if you need to get more information about your printer you can always fill out our online diagnostic form or come to our local provider for on-site diagnostics (https://bchtechnologies.com/printer-repair-service) but because we are usually busy with the demand services are provided on a first-come, first-served basis and in this case, you may wait for a while until you can have your printer checked out.

If you need more self-help, we suggest visiting our YouTube channel (https://youtube.com/@bchtechnologies) and using the search icon to the right of the "About" tab to find videos about power supply issues, troubleshooting mainboards, or printer repairs. Given nearly a decade of material, this is often the fastest way to locate the information you seek.

Thank you so much for your cooperation and understanding. I hope this is helpful. If you have more questions, don't hesitate to ask.