HP CM4540 MFP Communication Lost (device <-> control panel error)

**ucinn** · 05-16-2012, 05:16 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Originally posted by lane1957

Hello everyone!

I am new to the forum, but looking forward to interacting with such a talented group of people.

I was wondering if anyone has seen this error message on an HP CM4540 MFP. When I power it up it displays this error message on the Control Panel LCD display, "Communication Lost (device <-> control panel error)". I have the service manual on this unit, but it sheds very little light on what may causing this issue. I cannot tell if this is a bad Formatter board, or a bad DC Controller board. The machine will not print an Engine Test page. I have tried to print an Engine Test page with both the Formatter board installed, and again with it removed. No luck. I noticed that when the machine is powered up, the Formatter board heartbeat LED remains a solid green and does not flash/pulsate. I assume this is because the printer never completes initialization process. I have no spare parts to swap out in order to determine if it is a DC Controller board, or the Formatter board. Also, I have checked all the voltages on the LVPS and they are all present and correct. Any ideas on where to go from here would be great.

Thank you to all!

It sounds like DC controller to me just for the fact that it won't do an engine test correctly... the DC controller also communicates with both the formatter and op panel. That would be my best guess.

**lane1957** · 05-16-2012, 05:58 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Hey thanks for the reply uciin.

Interestingly, yesterday I had an HP tech. on the phone about this. He was adamant that it was a bad Formatter. I surmised the same thing as you, a DC Controller problem since it would not perform an Engine test, but the HP guy was "certain" it was the formatter

. I don't know if you have seen the service manuals on the HP "CM" series of MFP's, but they are not very good. Anyway, I informed my customer that it could be either board causing the problem and there was no way to tell which, unless one or the other was replaced. The boards are expensive, so needless to say he was not very happy about it. I have yet to hear back on what my customer wants to do, but based on the HP tech. input I suggested replacing the Formatter board first. I will post the results, if any, in this thread in case it might help someone else with this issue.

**ucinn** · 05-17-2012, 12:55 AM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Originally posted by lane1957

Hey thanks for the reply uciin.

Interestingly, yesterday I had an HP tech. on the phone about this. He was adamant that it was a bad Formatter. I surmised the same thing as you, a DC Controller problem since it would not perform an Engine test, but the HP guy was "certain" it was the formatter

. I don't know if you have seen the service manuals on the HP "CM" series of MFP's, but they are not very good. Anyway, I informed my customer that it could be either board causing the problem and there was no way to tell which, unless one or the other was replaced. The boards are expensive, so needless to say he was not very happy about it. I have yet to hear back on what my customer wants to do, but based on the HP tech. input I suggested replacing the Formatter board first. I will post the results, if any, in this thread in case it might help someone else with this issue.

Yes, the manuals for these HP's are not very helpful. That would be great to know which it was, my bet is still on the controller though.

**prntrfxr** · 05-17-2012, 02:16 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

I don't remember for that machine, but the service manual should say whether or not the formatter still being in the printer can affect the engine test results. Some machines you have to remove the formatter and then do the engine test. Of course, that means the display will be black, but it will either pass (print the pages with lines) or fail (not print anything).

**lane1957** · 05-17-2012, 03:40 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Originally posted by prntrfxr

I don't remember for that machine, but the service manual should say whether or not the formatter still being in the printer can affect the engine test results. Some machines you have to remove the formatter and then do the engine test. Of course, that means the display will be black, but it will either pass (print the pages with lines) or fail (not print anything).

The service manual does state that the formatter can affect the engine test results. Which is why I removed the formatter and tried the engine test again. The control panel does go dark, but if I understood the test procedures correctly, it should still be able to perform an engine test. In my case it does not. Interestingly, I also have an HP CM3530 in my shop with very similar problems. Same type of scenario. It comes down to either DC Controller or the formatter board. This one will not perform an engine test either, regardless of whether or not the formatter is installed or not.

I will post what the end results are when this is resolved. It may serve to help someone else with similar problems. Rather a perplexing problem. If I had an o-scope and a better circuit diagram maybe I could devise a way to determine a test that would define how to determine which board cause these issues. Sadly, I have neither and the service manual is severely lacking, at least on this type of problem.

Thanks to all who have making comments and suggestions. I really appreciate it.

**Sheppard** · 06-21-2012, 01:09 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Hello All, I've had two CM4540's with this error and replacing the formatter and disk drive cured this problem. I did try the engine test with the formatter installed and uninstalled and the engine test would not print. I installed formatter first with old hard drive (after disk clean and reload firmware) and had the same error. Installed new hard drive on old formatter same problem, installed both the new formatter and hard drive and machines rebooted to ready.

**prntrfxr** · 06-21-2012, 02:40 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Thanks Sheppard. Really, this error can be caused by either one as it is a failure in communication between the 2.

If a hard drive is installed (or other EIO optional device), I would remove it and see if the problem goes away. If it does, try reinitializing the hard drive. If that doesn't work, replace the hard drive.

If it does not have a hard drive, replace the formatter. Reason: 1) newer HP machines seem to have formatter weaknesses and 2) HP tech recommended it first (if you have a case number and the formatter doesn't fix it, you can return the formatter and get a credit.

If the formatter doesn't work, replace the DC controller.

**Sheppard** · 06-21-2012, 02:54 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Firmware is installed on the hard drive so unit cannot be booted without. I did a clean drive on both units and reinstalled the firmware before ordering the parts (no eio options or fax card installed) . I'm going out now to work on my 7th Cm4540 today in 8 days. Most of the time a partial clean or a clean disk and reload firmware will fix most of the problems. Don't believe eveything you hear from support.

**lane1957** · 06-21-2012, 05:21 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Originally posted by Sheppard

Firmware is installed on the hard drive so unit cannot be booted without. I did a clean drive on both units and reinstalled the firmware before ordering the parts (no eio options or fax card installed) . I'm going out now to work on my 7th Cm4540 today in 8 days. Most of the time a partial clean or a clean disk and reload firmware will fix most of the problems. Don't believe eveything you hear from support.

Update: The fix for the HP CM4540 turned out to be a faulty Formatter PCB. I had ruled out the hard drive by removing it, attaching it to a PC and running hard drive diagnostics on it, to check that the drive controller and platters were not damaged. The drive passed diagnostics. I spoke with my customer (who had both an HP CM4540 MFP and a CM3530 MFP) in my shop with these same types of issues. Based on feedback from the professionals that replied to this tread offering support, and what HP support was saying, I advised my customer to purchase a replacement Formatter PCB for the CM4540, and a replacement DC Controller PCB for the CM3530. It was the correct diagnosis for both machines. A replacement Formatter for the CM4540 solved the problem, and the replacement DC Controller for the CM3530 solved its problem.

It is unfortunate that the HP service manuals do not do a better job of providing detailed repair information for repair technicians where the formatter and DC Controller . Very sad indeed.

I would like thank all who took an interest in this issue. Your input proved to be invaluable and I wanted to say thank you very much!

Hat Tip to: ucinn, prntrfxr, and Sheppard for all your input. Very much appreciated. It was a terrific help to me on this. Thank you!

Very sincerely,

Lane

**BWB8771** · 07-27-2012, 01:47 PM

Re: HP CM4540 MFP message stops at "DISK CHECK 41%"

I tried to perform disk diagnostics with the hard drive outside the unit, but the drive is password-protected.

Can someone point me to the Service Manual, or tell me how to perform disk diagnostics/re-init on the CM4540?

**ucinn** · 07-27-2012, 05:46 PM

Re: HP CM4540 MFP message stops at "DISK CHECK 41%"

Originally posted by BWB8771

I tried to perform disk diagnostics with the hard drive outside the unit, but the drive is password-protected.

Can someone point me to the Service Manual, or tell me how to perform disk diagnostics/re-init on the CM4540?

feedroller.com has lots of HP manuals downloadable for free for HPs.

**BWB8771** · 07-27-2012, 06:13 PM

Re: HP CM4540 MFP Communication Lost (device <-> control panel error)

Found and d/l'd the manual - THANKS!

Now I'm stuck ad numeric admin password to be able to access the Service function...

HP CM4540 MFP Communication Lost (device <-> control panel error)

HP CM4540 MFP Communication Lost (device <-> control panel error)

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