We have an HP L7780 and have problems rec. faxes - error 232

Send a fax on this number
1-888 HP FAX ME (1-888-473-2963)

and see whether you receive a fax from hp or not whenever HP receives a fax from any number it sends back a fax to prove the functionality you can say.

the reason behind reviving the 1/4th fax can be fault at sender's end

These errors mean that the communications have failed, and can mean that the receiver at the other end has terminated the call prematurely.
If the problem occurs with the same destination, then the receiver fax may be the problem.
If the error persists try disabling ECM

Hello sir ; Why don't try to replace a phone cable or check the wall jack.

There are some settings that you need to change.

You need to turn off the following:
Error Correction Mode
Auto Reduction

to get to these options you need to go to the setup menu by pressing the setup button
then scroll to advanced fax settings and select it and you will find the options listed under it

You also need to check the fax speed under Advanced fax settings.
set it to medium.
hope this will help you :)

Please consult this page for links to fax error codes for your printer.
In particular, Error 232 yields this info:
Error Code: 232, 233, 234, 235 ECM, 236 ECM, 237
Definitions
A communication failure occurred between the two machines.
The user at the remote machine might have pressed the Stop key.
The call waiting service can cause this error. The click, heard for an incoming call, is actually a momentary disconnect of the line. Do not use call waiting on a line with a fax machine.
The power at the remote machine was interrupted, or deliberately turned off causing the fax session to be interrupted.

Solutions
If the error persists, and error correction is in use for the fax session, disable ECM. Fax quality might be degraded. Click here for instructions on enabling and disabling ECM (c00060802) (in English).
Set the host machine to receive at a slower transmission speed.
Retry the fax reception at a different time when telephone line conditions have improved. Call the telephone provider if line conditions fail to improve. These errors can occur if the phone lines in the area to be faxed are old or there is noise (static on the phone line). Other reasons can include power brownouts and other power-related problems.
You can also access the home support page for your printer here., in case you should have further troubles.

I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
If I've managed to answer your question or solve a problem, please take just a moment to rate this post....thanks!

Check this troubleshooting page from HP Support:
HP All-in-One or Fax Product - Troubleshooting Fax Transmission and Reception Issues

basically error 232 indicates that a communication failure has occurred between the two machines
Following these steps may help resolving your issue

1. Make sure that the phone cord is plugged directly from the wall jack into the back port of the fax machine that is marked "Line" or "To Wall Jack", or that has a wall-jack symbol.
2. Verify that the line interface unit (LIU) (the box that the phone cord plugs into) is seated fully into the back of the fax.
3. Remove any other device from the line such as splitters, credit card machines, or telephone answering machines, and retry the fax communication.
4. Try sending and receiving faxes on a different fax line.
5.Try using a different telephone cord.
6. Have the phone company test your line for static or noise problems.
7. Disable Error Correction Mode (ECM) if the same error occurs repeatedly.

Hope this helps.
thx

Sam here. Anyone have a solution?? We use a voip setup for phones. Wondering if its related. We have signal converter boxes installed.

232-A communication failure has occurred between the two machines.
327-*Reattempt the fax reception at a different time when telephone line conditions have improved. Call the telephone provider if line conditions fail to improve.
356-The remote user has pressed the Stop key, causing the session to be aborted.
442-An error occurred during transmission after one or more partial pages had been sent. The transmitting machine was unable to restart the control channel (handshaking) before sending more data. This error typically occurs when the receiving fax disconnects after receiving part of a page but can also occur if the receiving fax is using a fax format that is incompatible with the HP fax machine (usually during color faxing).

fax error 232 indicates a communication failure between the sending and receiving units. I'd check for line noise on the phone (you can hear it as cracks and pops) If your fax line is not dedicated, any noise from another phone pickup or an answwering machine can cause the failure.