HP Laserjet 4345 Wont come ready...

**Doug James** · 09-26-2016

The screen keeps showing the invent screen and the lights are flashing like it it coming up but never does. Is this the hard drive and is their anyway I can try to fix this ? Thanks so much for any help !!!

**Doug James** · 09-26-2016

Think this link is going to help me out...

Hp m4345mfp booting up issues +

**1stcavvet** · 09-27-2016

The HP on the display starts small and gets bigger and bigger and all the lights are blinking in sequence RIGHT It's the power supply the unit that is under the toner cartridge has the conveyer on top, have you ever had to do a swing plate on a 4250. When you get to the part where you slide the power supply out the back. that's what you have to do to the 4345. couple hours if you never had one of these apart.

**Doug James** · 09-27-2016

Originally Posted by 1stcavvet

The HP on the display starts small and gets bigger and bigger and all the lights are blinking in sequence RIGHT It's the power supply the unit that is under the toner cartridge has the conveyer on top, have you ever had to do a swing plate on a 4250. When you get to the part where you slide the power supply out the back. that's what you have to do to the 4345. couple hours if you never had one of these apart.

I had just changed the swingplate... The copier came up and ran OK for a bit... Maby didn't get a wire in very well...

**1stcavvet** · 09-27-2016

check those wires and flat cables that's the only wires from the power supply check the wires on that little board in the bottom right hand corner in the back also GOOD LUCK

**Doug James** · 09-27-2016

Originally Posted by 1stcavvet

check those wires and flat cables that's the only wires from the power supply check the wires on that little board in the bottom right hand corner in the back also GOOD LUCK

Thanks so much !!!

**Doug James** · 09-28-2016

Originally Posted by 1stcavvet

check those wires and flat cables that's the only wires from the power supply check the wires on that little board in the bottom right hand corner in the back also GOOD LUCK

I went to this machine today and got it working. I am not sure but I think the AC wires that come from the power supply were to close to the wire strip. That's all I could figure. It is still acting flaky though... It keeps initializing the scanner. And it won't run a copy off the glass.... I can get it to run one from ADF. Tomorrow I am going to re-install firmware and go from there. What a mess... Talk about tech lightning... There was dust all through this machine and think that is a lot of my problem...

**subaro** · 09-28-2016

I have refurbished quite a number of these machine, with the swing plate and all. They work really well once serviced properly, even with the dust caked all over. If before you did the swing plate, the machine was working well, then you have to recheck your installation again. Make sure the humidity sensor is clean and installed properly. Unplug the wire harness that goes from the dc controller to the engine pwb. make sure they are inserted firmly. Also make sure the dc power supply frame is sitting properly or the formatter would not install correctly. This machine, you have to be precise in the reinstalling of the parts or you will get issues. good luck.

**Doug James** · 09-28-2016

Originally Posted by subaro

I have refurbished quite a number of these machine, with the swing plate and all. They work really well once serviced properly, even with the dust caked all over. If before you did the swing plate, the machine was working well, then you have to recheck your installation again. Make sure the humidity sensor is clean and installed properly. Unplug the wire harness that goes from the dc controller to the engine pwb. make sure they are inserted firmly. Also make sure the dc power supply frame is sitting properly or the formatter would not install correctly. This machine, you have to be precise in the reinstalling of the parts or you will get issues. good luck.

Thanks so much really helpful !! Need all the help I can get on this one... Appreciate you

**Doug James** · 09-28-2016

Originally Posted by subaro

I have refurbished quite a number of these machine, with the swing plate and all. They work really well once serviced properly, even with the dust caked all over. If before you did the swing plate, the machine was working well, then you have to recheck your installation again. Make sure the humidity sensor is clean and installed properly. Unplug the wire harness that goes from the dc controller to the engine pwb. make sure they are inserted firmly. Also make sure the dc power supply frame is sitting properly or the formatter would not install correctly. This machine, you have to be precise in the reinstalling of the parts or you will get issues. good luck.

Having trouble finding the Humidity sensor in the manual... Are you talking about the thermistor on the fan that plugs into the engine PWB ?