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Fuses & Printhead

edgaryn

New Member
I have a problem with my Mutoh ValueJet 1204 printer will not print anything .. probably printhead cable not in correct place... Where can I look for a diagram to check this and also need to know where the fuses are located in order to check if they are damaged​
 

Biker Scout

New Member
It's probably just clogged.

You need to give more description as to what the printer is actually doing, or not doing. When you send a file does it do anything? Warm up, pretend to print just nothing comes out? Is the printer just sitting there idle, no flashing light? etc...
 

edgaryn

New Member
First... I had trouble only with magenta color. it wasn't printing at all ... Printer makes its starting routine normally and gets ready to print ... I send a file to print and start working as if it were printing but nothing comes out .. I did a few strong cleaning with no results. Then I used a syringe to fill Dampers.. and same result .. nothing came out. I also checked that vacuum lines were not clogged using some solvent watching the drops fall into the waste deposit.
I put the printhead in solvent through the night and again filled the lines and Dampers. I put some solvent for each entry in the printhead .. but I'm not sure if I put back the printhead cables correctly because no color is printing now. I don't have the service manual yet..I want to locate the fuses for checking. i'm going to order the manual from Signwarehouse next monday.. I hope they got it and share it with me.
Excuse my bad English and grammar
I appreciate your help
 
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Biker Scout

New Member
What sounds like is going on is that you starved your print head and may have some clogged nozzles as well as a weak vacuum pull.

See, once you get to that point, you can't just put cleaning solution in and watch for dribbles in the waste tray. It needs to come pouring out.

I'd start by removing the side panel, and then unscrewing the capping station. It's got two hoses underneath that you need to remember how and where you took them from.

Inspect the little rubber trim ring around the capping station when it's completely out. If there's any ink build up, remove it, and check for little cracks or tears. Be careful with the capping station, if it appears to be in OK shape... because a new one is like $600, for that little bit of plastic.

Now inspect those little black hoses. By now, you would have noticed if they unplugged from the larger diameter clear hoses, and if there was a little plastic tube connector connecting the two. If there is a little hose barb connector thing, throw it in the basura! The black hoses will slide perfectly into the clear hoses with no leak. If you are so inclined, try and find something that will clean that little hose barb you are about to throw away. Unless you have needles around the shop, nothing short of super thin gauge wire will fit in there. That's a huge bottle neck, and I think it was installed on purpose to generate more on-site service calls. As it serves no real purpose other than to mess your printer up from time to time.

Anyway, back to the black little lines... these clog rather easily. However with your syringe, you might be able to flush fluid through them just fine, and think they are OK. They usually are not... squeeze between your fingers and you can feel they are hard. They clog much like artaries, and still allow tiny amounts of fluid to pass, but have little caked ink along the inside walls. Continue to mess with those until you are certain they are empty of little ink plugs.

Now you can flush fluid though the clear lines, and notice a lot of gunk build up there too... but these hoses are made of silicone and nothing really sticks to the sides once you send a few syringe pumps of cleaner through.

Now put everything back together and run a regular clean cycle a couple of times to try and re-prime the printhead. (You should probably leave the side cover off at this point until the printer is really printing again)

If it's still not printing, you've got printhead flow problems. For some reason, magenta is the one that goes bad first. hmm...

From this point on you need to be brave enough to pull your printhead off and give each fill port a good cleaning. However, a new printhead is $1200 and if you aren't comfortable in removing it, then don't. Just keep running the cleaning cycle and re-prime the printhead by using the printer's own pump.

After clearing out those lower hose lines, you should actually be nearly back to normal... my guess is that all the colors will eventually come back 99% - 100%, but you'll see what looks like clogged magenta nozzles that are missing. If that's the case still... you need to consider a sonic cleaning, or a new printhead. You can soak the print in a shallow bath of solution, and try to force solution though the tiny holes on the backside of the printhead, but it's tedious and hard to do. I actually shot cleaning solution straight into my eye once, because the syringe I was using wasn't pushed tightly up against the fill holes, and "FIIITTT!" shot straight back up into my eye. Luckily I was wearing contacts, and it didn't do any damage to my sensitive areas. Just stung for about an hour, even after I flushed it.

Anyway, back to the fix... yeah, just clean the hoses underneath and see what that gets you. Have some custom test squares set-up and ready to print. The usual, CMYK 100% values of each, Red, Greens, Oranges, Blues, Purples. That way when you start to print again, you can see what colors are lacking. Then, you determine if you need to fiddle with the print head.

Good luck.
 

edgaryn

New Member
thank you very much for your very detailed explanation .. no doubt It will be very useful .. i'll let you know the results
 

edgaryn

New Member
Hello .. I followed your instructions and put special care in the capping station and the 3 black color lines .. the longest was totally clogged. I used some solvent and a thin wire to clean it.
unfortunately when I tried to fill the lines and dampers with ink, I heard some air leaking from magenta and black dampers so i have to order some as soon as possible to replace them. I'll have to wait a few days to know the result .. I need to know the correct way to connect the printhead cable .. if anyone knows, please let me kmow.. also I need to know where the printhead fuses are located. if there are some.
 

Biker Scout

New Member
The printhead ribbon cable can easily be put in wrong just by they way they lay next to eachother. However, if you look real carefully at the input on the side of the printhead, you will notice the pins face only one way. One row faces up and one down. The ribbon cable also has exposed pins that only face one way. The only way to get them mixed up and actually making contact with the pins, is to twist the cables, and you'll see that's obviously not right. Don't fire up you machine with them like that or you will blow your printhead.

Just look for the writing on the outside of the ribbon cable. That one goes in the bottom row.
 
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