Ricoh C4504 strange problem, Black screen but not always

[BartLow]

I have a strange problem on one of my c4504s. When I press the “Turn on” button, the printer seems to start (it starts to make noise - the belt turns, the fused heats up, etc., but the screen does not light up (panel don't start). Also I don't see any light leds on main controller board, but the hard drive is spinning up. When I press power button again, the screen turns on, panel loading but after i see the “shutdown” message and machine turns off.

I disconnected all connectors from the IPU expect power button, power supply, power supply control and screen, but nothing changes. All three incoming lines of 5V on IPU connector seems ok.

[luca72]

I have a strange problem on one of my c4504s. When I press the “Turn on” button, the printer seems to start (it starts to make noise - the belt turns, the fused heats up, etc., but the screen does not light up (panel don't start). Also I don't see any light leds on main controller board, but the hard drive is spinning up. When I press power button again, the screen turns on, panel loading but after i see the “shutdown” message and machine turns off.

I disconnected all connectors from the IPU expect power button, power supply, power supply control and screen, but nothing changes. All three incoming lines of 5V on IPU connector seems ok.

i for first thing, I would try the panel of another machine, just to discriminate between the panel and everything else, some panels that failed, it happened to me
if you left the start panel in normal mode, you can try to update the firmware, but im not very fiducious.

[slimslob]

Can you access WIM to see if there are any error messages displayed there? Have you tried a full power down to clear any lock circuit?

[BartLow]

Can you access WIM to see if there are any error messages displayed there? Have you tried a full power down to clear any lock circuit?

No, seems ethernet controller power up but I can't connect to machine

[BartLow]

I think problem in IPU, perhaps the main controller is not receiving all the necessary power line. I checked 5V lines and it's ok. Where is 3.3V here?

[BartLow]

i for first thing, I would try the panel of another machine, just to discriminate between the panel and everything else, some panels that failed, it happened to me
if you left the start panel in normal mode, you can try to update the firmware, but im not very fiducious.

Another panel don't work also in turn, the panel of this machine on another machine starts normally

[BartLow]

Startup process