Diagnosing Epson L3250 Printhead: Is Diode Mode Enough?

[mdrydary]

Hello, and thank you for your helpful content.I have a question regarding printhead diagnostics for the Epson L3250.I'm trying to determine whether the printhead is electrically healthy or if there's an internal short or open circuit.Is it sufficient to use the multimeter in diode mode with inverted polarity to detect electrical faults in the printhead? Specifically, I placed the positive probe on the ground pin and the negative probe on each signal pin.My readings were:• Pin 1 = 0• Pin 2 = 0.647• Pin 3 = 0.573• All remaining pins = 0Does this indicate that the printhead is functioning correctly, or could there still be hidden faults that require testing in both directions or using resistance mode?I would appreciate your expert opinion and guidance. Thank you in advance.

 

[Ink stained Fingers]

Such electrical measurement won't tell you anything about clogged nozzles.

What is the problem you have with the L3250 ? It is very successful flushing the printhead - wihtout
taking it out , there are plenty Youtube videos showing the process.

 

[mdrydary]

Thank you for your reply. I would like to clarify my situation: I removed the Epson L3250 printhead and cleaned it with a special cleaning solution. Unfortunately, some of the solution reached the electronic part of the printhead. When I reinstalled the printhead and powered on the printer, the printer lost power completely — it caused a short circuit that damaged the mainboard. I repaired the mainboard and then dried the printhead thoroughly, leaving it for two days to ensure it was completely dry.

Now I would like to test the printhead with a multimeter to know whether it is still electrically healthy or if it has been damaged. Could you please guide me on the correct way to check the printhead with a multimeter? I would really appreciate your expert advice.

 

[Ink stained Fingers]

I don't think there is any way to measure some ohm like resistance on piezo elements driving the nozzles. You can assume that the piezo elements are arranged in a kind of matrix, it otherweise woould not be possible to address hundreds or even thousends of piezo elements separately. Epson most likely has some specific printhead test unit on manufacturing or repair level. This is far beyond a level users have access to. You may try to get a replacement printhead via aliexpress, it may work - or not and you claim waranty for refund, but I'm rather reluctant to mention this option. Such printheads are used and cleaned up and probably tested, but it may not work - the risk is yours.