HP 4890 Maintenance Manuals?

[ramjr]

I have an old scanjet 4890 scanner that no longer turns on the light to scan but is fully functional otherwise.  I am hoping there is a maintenance manual that would help me troubleshoot internal connections.

[NonSequitur777]

@ramjr,

Welcome to our HP Community Forum!

Here you go: c00437630.pdf (hp.com).

Kind Regards,

NonSequitur777

[ramjr]

Hello NonSequitur777,

Thanks for your quick response.

Unfortunately, I'm looking for something more detailed.

What I need to know is how to open the thing up (correctly, so I don't break something), find internal connecctions and things to check.

This document basically tells me to be sure my USB cable and power cord are plugged in securely and that the lid connection is tight. 😞

Thanks for the link, it is good to have at least this much.

ramjr

[NonSequitur777 · Accepted solution]

@ramjr,

The lid connection is indeed reportedly to be very tight and needs to be lifted straight up.

Unfortunately, I could not find a specific disassembly guide for an HP Scanjet 4890.

I wondered, though, if this instructional YouTube link for an HP Scanjet G4010 -which bears many similarities to your Scanjet, could be of any help: (148) How To Open Hp Scanjet- G4010 And Servicing | Easy Electronic Solution - YouTube

Kind Regards,

NonSequitur777

[ramjr]

Hi,

Yes indeed, this was helpful.  I did have to remove 4 screws from the backside, but then using the video as a guide, it was fairly simple to pry up the top (verrry carefully 😉 until it popped out.

So now I have access to the insides and can figure out how the light assembly works.

Thanks again,

ramjr

[NonSequitur777]

@ramjr,

You are very welcome, glad to have been of service!

Kind Regards,

NonSequitur777