No Lights on first power up

[Benkrygsheld]

Need some help troubleshooting a Rostock Max V2. I finished assembly last week, went to turn it on and surprise nothing lit up. I was told to turn the cables running to the LCD the other way. Did that. Nothing. The RAMBO board does not light up, nor does the LCD but the boards fan does power up and spin.

I contacted support and was told it was a fuse and I'd need to order replacements. So I did. In the meantime I picked up a multimeter. Fuses arrived today, checked on the internet how to test them and did so. Tested good. Pulled the old fuse and it tested good , swapped the fuses anyways. Nothing.

[Eric]

[img]http://reprap.org/mediawiki/images/b/ba ... n-main.jpg[/img]

You have a multimeter. Good. Set it on a DC voltage scale and check the input voltages from the power supply. Measure between + (red probe) and - (black probe) on each of the A B C power input pairs. They should all be very close to 12V DC. If not, disconnect the plug from the board and measure again. If still wrong, you've either got a bad power supply or bad wiring of the connector.

Do you have any color vision issues? Make sure you can tell the difference between the orange wires (3.3V) and yellow wires (12V). Make sure you are only using yellow wires for 12V and black wires for ground.

If that's not the problem, perhaps pictures of the board as assembled will let us spot the issue.

[Benkrygsheld]

All three pairs show 12.3 V.

[Earthbound]

Take a very close look at the LCD adapter board. The solder joints nearest the ribbon cable in your picture look like there might be a bridge between pins. May just be glare, but worth checking.

[Eric]

The logic is powered by 5V regulated down from 12V on the board...even when shorted, that regulator won't draw enough current to blow the 12V fuse. Measure what voltage the 5V area has, if any. The easiest spots are probably the bare pads in the upper left corner of your picture near the "5V aux out" label or the +/- pins on any of the endstop connectors (refer to the diagram I posted before). I'm guessing you'll find no voltage indicated, indicating a probable short somewhere. Earthbound may have already spotted it. If you do find 5V in those places, then I'd guess the cpu likely isnt working and you need a replacement board.

You can remove the LCD cables and adapter board as a test. The main board is supposed to power up without the LCD. If it does, it identifies the LCD adapter/cables/panel as the problem area. If it doesn't, it eliminates them as the cause of this problem.

You can also unplug your endstop connectors from the board as a test. If wired wrong you could be shorting power to ground that way.

Finally, just eyeball everything for anything that doesn't look right. A small piece of loose wire from whatever wires you had to cut/strip. A random solder blob that dripped off the soldering iron if you used one. You may get lucky and find something easy to fix.

[M-I-H1]

I am having the same problem, finished assembly of my Rostock MAX V2 last evening, on power up I do get 2 flashes from the Status LED (yellow) and a solid green LED on the RAMBo, but nothing on the LCD. All fans are running and have 12.2V coming in.

[Eaglezsoar]

I am having the same problem, finished assembly of my Rostock MAX V2 last evening, on power up I do get 2 flashes from the Status LED (yellow) and a solid green LED on the RAMBo, but nothing on the LCD. All fans are running and have 12.2V coming in.

It is possible to plug the cables from the LCD into the Rambo backwards. Be sure the red wires are on the right as you look at them plugged into the adapter and the back of the LCD, please check them and get back to us.

[M-I-H1]

I had them to the right, as the instructions said for the red LCD board, I just tried putting them on the left and and it seems to be working. Thanks.

[Eaglezsoar]

I had them to the right, as the instructions said for the red LCD board, I just tried putting them on the left and and it seems to be working. Thanks.

I am glad you got it working. Sometimes I think the LCD manufacturers put the ends on the cables wrong.

[Benkrygsheld]

Winner winner, give Earthbound a prize. The LCD board did have a really ugly solder joint causing the problems. I cleared the extra solder and am able to continue.

[Benkrygsheld]

Argh! Now after uploading the firmware I have lit but blank LCD screen. I know the firmware uploaded because if I hit the reset button above the selector knob the carriages raise to the top and are stopped once they hit the limit switches. I've also played with the contrast. Screens lit, just blank.

Am I missing something still or bad part?

[Eaglezsoar]

Argh! Now after uploading the firmware I have lit but blank LCD screen. I know the firmware uploaded because if I hit the reset button above the selector knob the carriages raise to the top and are stopped once they hit the limit switches. I've also played with the contrast. Screens lit, just blank.

Am I missing something still or bad part?

As a couple of threads above you indicates, try swapping the cables on the lcd adapter. Turn the machine off - rotate one of the cables and plug back in - power up and see if your lcd works. Rinse and repeat if necessary. (rotate both cables if you have to)

[Benkrygsheld]

That has already been done. I get nothing if I rotate the plugs.

[Eric]

Which firmware did you upload? Was it one already pre-configured by Seeme?

When you fixed that adapter board, did you check the solder job on the back side of the board also? Might be worth a look if you didn't.

[Benkrygsheld]

Thanks for the help everyone. I did check the other side and noticed no issues, and I was using the firmware from SeeMe.

Ultimately they sent me out a replacement for that little LCD board and I was able to move past this issue.