Brother MFC-9460cdn laser printer not detected in USB  (Not a driver issue) - Page 1
Forum section: electronics / repair

author: touchatout
author_rank: Contributor
timestamp: March 12, 2025, 08:43:14 pm
content: Hi,I have Brother MFC-9460cdn laser multifunction copier, which is perfectly working standalone, but isnot detected when connected to the PCin USB.The problem isnot related to the driver(which is present and also has been reinstalled),not the USB cable(working with other printer), andnot computer related(several laptops used, both Windows and Linux).When the USB cable is plugged to the computer, anunknown deviceis instantly detected.Windows 7 also report a message telling the device isnot recognised due to malfunction of device(Error 43).There is no over-current warning.I replaced the USB 2.0 socket and this didn't bring any improvement.I could not truly test the printer with the RJ45 socket (Ethernet). I can connect it to the office network but don't have access to the router. It was not detected when conntected to the network. So, I am not sure if the problem is with all data connection or only with the USB port.5V power supply---------------------- I can confirm that pins 5V and GND are not shorted : scratched the painting + continity check doesn't beep- I must admit that I don't understand well the usefuleness of the 5V pin, as both the printer and the computer are powered independantly.Data pins------------- From the USB socket, the data pins D+ / D- follow a long path without intermediate components which ends opposite to the board controller.Controller: reflow it or not-------------------------------The largeA51171-ARTEMIS controller is not stabilized by epoxy at its corners. Since the printer is from the times of DDR2 memory, I would not be surprised of a cracked solder ball.However, I am reluctant reflowing the board, because it is dual side and because past experience of loosing small components by gravity or air blowing.I have polyimide film (Kapton-like) to prevent the loss of components, but even with that, it is quickly a nightmare if tiny components unsolder themselves by gravity and are catched/glued by the film.I have a kitchen convection oven, whose temperature regulation accuracy looks being around 30°C.(When this oven reaches the desired temparature and stops heating, I have to rotate the button by about 30°C for the oven to start heating again.)I would not preheat more than 150-160°C with it, because of its inaccuracy and plastic sockets on the board.I also have Yihua 852D+ hot air station to put some heat boost on the controller and possibly reflow it.I have been sometimes sucessful and not other times.----------------------------------Apart from replacing the board,what would you adviseto attempt diagnosing / repairing it ?

author: m k
author_rank: Super Contributor
timestamp: March 22, 2025, 05:30:29 pm
content: What vid/pid lookup is saying?

author: mon2
author_rank: Frequent Contributor
timestamp: March 23, 2025, 12:56:20 pm
content: Remove all power. Meter in diode mode. Red meter lead, yes red to ground (metal shield is ok). Black meter lead to point to test. Test the D+ pin. Test the D- pin. Post each measurement. A low voltage can mean a shunted tvs esd diode in the path or defective host controller on this logic board. Assuming there is an esd protection device or usb load switch on board. Share more pics to confirm.

author: fzabkar
author_rank: Super Contributor
timestamp: March 24, 2025, 09:44:57 pm
content: Service manual:https://elektrotanya.com/brother_dcp-9055cdn_dcp-9270cdn_mfc-9460cdn_mfc-9465cdn_mfc-9560cdw_mfc-9970cdw.pdf/download.html

author: touchatout
author_rank: Contributor
timestamp: March 30, 2025, 12:06:16 pm
content: QuoteThank you. Measurements obtained are:D+: ~0.2 VDC(0.195 with Fluke 87 and 0.203 VDC with Fluke 70)D-: ~0.085 VDC(0.081V with Fluke 87 and 0.089 VDC with Fluke 70)N.B. Measurements done with the red meter lead directly to GND solder point tended to be much more stable than those with the red lead to the metal shield.QuoteView of LT1 096 B57T022-2 circuit boardfrom Brother MFC-9460CDNhttps://imgur.com/a/5eNHpLPBack face of LT1 096 B57T022-2 circuit boardfrom Brother MFC-9460CDNhttps://imgur.com/a/RyeBwJfQuoteThank you for the service manual and introducing me toElektrotanya.com, a great website I didn't know about.

author: m k
author_rank: Super Contributor
timestamp: March 30, 2025, 06:23:52 pm
content: Was my question too irrelevant?Go to Device Manager and check VID and PID of the printer.If that's still Brother check some other settings that should be mastered by the printer.You can create a static network between a computer and printer with a crossover cable.

author: touchatout
author_rank: Contributor
timestamp: March 31, 2025, 12:35:13 pm
content: QuoteSorry, I was not understanding what you meant by vid/pid lookup.QuoteIn the devices details for the unknown device is no "Brother" detected but only some USB device with problem.QuoteThank you. I didn't know that and you've taught me something. However, the problem seems coming from a corrupted EEPROM as I will detail below.When I power the printer on, thestart sequenceis as follow:timing ~ 3 seconds: 5 beeps (probably normal)timing ~ 5 seconds: 5 beeps (probably normal)timing ~ 10 seconds: Error message "No printing possible", witherror code EB, and additional information "No station ID".According to thetable on page 2-24 of the Service Manualdownloaded from the link provided by fzabkar,https://elektrotanya.com/brother_dcp-9055cdn_dcp-9270cdn_mfc-9460cdn_mfc-9465cdn_mfc-9560cdw_mfc-9970cdw.pdf/download.htmlthe problem for the error code EB is "Read error in EEPROM of the laser unit".It is suggested turning the printer off and on again, but it doesn't solve anything in my case.Then, one should refer topage 2-98 of the Service Manual.Thepossible causesfor error code EB are:1 Harness connection failurebetween laser unit and main PCB ASSY2 Laser unit failure Replace the laser unit.3 Engine PCB failure Replace the engine PCB ASSY.4 Main PCB failure Replace the main PCB ASSY.As for the first possible cause, I see that one pin on the flex ribbon between the two PCBs issligthlydamaged. It should apparently not prevent proper contact, but to be sure I will tin this pin again and see ...

author: m k
author_rank: Super Contributor
timestamp: March 31, 2025, 06:40:43 pm
content: Harness connection failure is very precise, station ID then is possibly very primitive.I'd guess that ID is the very first thing that the MCU is trying with the laser unit.So I'd say that any USB stuff is actually very irrelevant for now.Generally laser unit is very simple, no adjustments and packet in plastic.But inside it can be a rotating deflection polygon, so don't open it even if you can, you don't know what is zinging out.With luck you have a missing voltage somewhere, but you can't be sure without measuring it when the process is on, so some add-on wires sticking out from somewhere is most likely needed.

author: touchatout
author_rank: Contributor
timestamp: April 02, 2025, 05:49:47 pm
content: QuoteThis is my impression too.I removed the small board framed in yellow on the picture below, and inspected the end of the ribbon circled in orange.It was slighly bent in the corners, but not really damaged.The connectivity along all its tracks was confirmed OK.I tinned the end of each track to improve contact.After putting the small board back in to place, and carefully reconnecting everthing, the error is different.The "no station ID" is still displayed from the very beginning, but the error code telling about printing impossible changed from EB to 73.According topage 2-21of the service manual, the problem associated toerror code 73is "Beam detecting error (Cyan/Magenta) error of the laser unit".The suggestedstepsfor this error are atpage 2-60of the manual:Harness connection failure oflaser unit: Check the harness connections (at threelocations) of the laser unit and reconnectthem.Laser unit failure: Replace the laser unit.Engine PCB failure: Replace the engine PCB ASSY.Main PCB failure: Replace the main PCB ASSY.I don't know if error numbers come sequentially, i.e. if the check that leads to error 73 comes before the one outputing error EB, or not necessarily.I cannot think of anything I would have done wrong by removing reinserting cables.So, I am now stuck on error code 73.I must admit that so far I could not find the time to read the manual as a whole.

author: touchatout
author_rank: Contributor
timestamp: April 02, 2025, 07:26:17 pm
content: It is extremely frustrating: after powering the printer off and on again, now havingerror code 72: "Beam detecting sensor (Black/Yellow) error of the laser unit.".Suggested steps are same as for error 73, as mentioned in my previous post.So, I assume that the color toners (or the drums) are not detected.I checked that they were properly inserted, removed the toner cartridges, removed the drums tray, and put everything back into place.The cartridges and the tray see propertly inserted. Wires and ribbons seems all properly connected.

author: m k
author_rank: Super Contributor
timestamp: April 03, 2025, 06:18:29 pm
content: So now one question is how beam is detected.Back in the day the open frame system had a simple sensor that blinked when deflected beam swiped it.Since station ID is now found the situation is heavily pointing to harness.Maybe your tinning is partially too thick.It's also possible that the PCB connector has been more or less bad for a longer time.