Bad fax component in HP OfficeJet Pro 7740

[Awvarwy]

So, I have a classic problem... "The printer's fax component has become damaged and cannot perform the fax test."  The printer is out of warranty.  A power outage seemed to have contributed to the issue.  When the phone line was plugged in after the power outage, the 7740 would tie up the phone line.

So, I know I need to replace the fax component, but from where, and what is the part number?  I found the HP parts surfer website, https://partsurfer.hp.com/Search.aspx?searchText=G5J38A, but nothing has "fax" in the description.  One would think I should find the fax module under the heading "PC Board".  I assume the board I need to replace is the one with the phone ports mounted on it.  However, without a part number, Ebay is pretty difficult to sort out.

Everything about this 7740 works fine!  It prints well and fast, it scans accurately, and the wireless unit is able to connect to devices around the house.  I don't want to have to replace this unit.  I would rather replace the damaged card.  So, what do I need to procure to fix this, and where can I get it?

Thanks!

[Valsimot]

The fax module component is embedded in the printer's mainboard, that's is the reason you can find the spare part number on HP partsurfer.

You need to change the whole printer's mainboard when fax fails. 😥

[Awvarwy]

Valsimot, thank you for indicating that the fax component is actually part of the motherboard (although this is contrary to an Ebay search I did six months ago which indicated they had a separate part that was the "fax component", complete with its own part number; the image of the part was a card attached to the phone jacks... it was $24.99 plus shipping, and I don't know why I didn't buy it then).

However, if the fax component is indeed part of the motherboard, I go back to my original questions... what is the part number and how do I buy it?

Thanks!

[Valsimot]

The information you previously found on eBay was probably wrong or for the wrong printer model.

The spare part number from mainboard is G5J38-60134.

[Awvarwy]

Thank you for the part number.  Where is a safe place to buy this motherboard?  What is too much to pay?

Thanks!

[Valsimot]

Just buy locally to avoid possible regionalisation issues.