Color Laser Hp 4650, Dead Display

[KHAN]

hi,
Ihave Hp 4650 Color Printer ,the Display Is Completly Dead,no Led Glows And The Lcd Is Also , But When I Turn On The Printer It Takes Its Warmup ,but Display Is Totaly Dead, I Want To Know Before Checking The Power Supplty Pcb ,is There Any Thing Or Some Codes To Turn On The Display?

[wild bill]

hi,
Ihave Hp 4650 Color Printer ,the Display Is Completly Dead,no Led Glows And The Lcd Is Also , But When I Turn On The Printer It Takes Its Warmup ,but Display Is Totaly Dead, I Want To Know Before Checking The Power Supplty Pcb ,is There Any Thing Or Some Codes To Turn On The Display?

Hello, Here is what is in the service manual RE: Trouble shooting.

Troubleshooting power-on
When you turn on the printer, if it does not make any sound or if the control-panel display is blank,
check the following items:
1 Verify that the printer is plugged into an active electrical outlet that is of the correct voltage.
2 Verify that the on/off switch is in the ON position.
3 Make sure that the rear fan is running, which indicates that the system is operational.
4 Verify that the firmware DIMM (HP Color LaserJet 4600 models) or CompactFlash (HP Color
LaserJet 4610n and 4650 models) and the formatter are seated and operating correctly.
5 Remove any HP Jetdirect or other EIO cards, and then try to turn the printer on again.
6 Make sure that the control-panel display is connected.
7 Check the fuses in the power supply.
8 If necessary, replace the power supply.
9 If necessary, replace the DC controller.
262 Chapter 7 Troubleshooting ENWW


I have seen the panel go blank when I forgot to put back a dimm. Try reseating all and the reseat formatter also. Good luck!

[KHAN]

thanks For Reply,
ok I Will Check These Points , The Machine Truns And The Fan Also Work The Heater Unit Also Heats,

[KHAN]

i Visit The Customer Office Today , I Checked All The Points That You Mentioned ,all The Fans And The Heater Unit Works When I Trun On The Printer,
but What They Do , They Says It Was Ok But They Refill The Colors Cartridges And The Printer Work Just For Few Hours And Then Happens That . I Am Going To Check The Power Supply Unit ?