VJ1638x Printhead Problem

[Dean Dos]

Just got a used VJ1638x, there was an encoder error which I have fixed. ran a nozzle check, and printhead 2 was clogged, tried cleaning multiple ways, but only got it to fire 1 nozzle partially (magenta). So figure can't break that is already broken, got a little more aggressive with the clean.
Took the printhead out, removed the dampers, and let soak the cleaning solution overnight. In the morning, put it all back together, and now it is coming up with a Head Temp 2 error. Removed the printhead to inspect and noticed that while I was blowing out and cleaner from the connector I damaged the ribbon cable on the head.
Well - my bad - So I ordered a new Head, from China (a lot cheaper) and installed the new head, and now comes up with a Head Heat Error. After research, I found that there is an encryption code that you need to put into the printer. The new printhead is wrong only has a 7-digit code, not an 8-digit code.
Went into Parameters and shut off the Head Heat check. This allows me to start up the printer, and run a nozzle check, now both heads don't fire a drop.
Question - shutting off head heat, will this cause both heads to not fire at all, or is it just not firing because the printhead 2 has bad encryption?
Question 2 - is there a way to shut off Printhead 2 at start-up, to be able to print with only Printhead 1 - right now it will not get past start-up with Head Heat Check On

Any thoughts would help - if anyone has access to a full-service manual that would help greatly

 

[Ssignature]

E 188 Err Head Heat 1
E 189 Err Head Heat 2
This indicates that Head
driver is malfunctioning.
Print head, Head FFC, or CR_FFC may be
malfunctioning.
1. Replace Head FFC.
2. Replace CR_FFC.
3. Replace Print head.
"3.7.11 Replacing Print Head"
p.3-151

E 190 Err H Trans Th.1
This indicates that Head
transistor 1 is
malfunctioning.
The temperature of Head transistor 1 of MAIN
board may be abnormal, or the sensor of
Thermistor 1 may be malfunctioning.
1. 1. Replace MAIN board.
2. 2. Check the connection of CR_FFC and
Head FFC.
3. 3. Replace Print head.
"3.4.12 Replacing MAIN board
Assy" p.3-53
"3.7.11 Replacing Print Head"

E 191 Err H Trans Th.2
This indicates that Head
transistor 2 is
malfunctioning.
The temperature of Head transistor 2 of MAIN
board may be abnormal, or the sensor of
Thermistor 2 may be malfunctioning.

 

[Ssignature]

Menu key>Setup menu>Single Head menu

You can set whether or not to perform printing using only one Print head.
NOTE
• This printer has 2 Print heads inside Print head unit.
• Even if “Head 1” or “Head 2” is set, when performing the Test print menu, the both Print heads are
used for printing.
• When “Head 1” or “Head 2” is set, if “A-S. Fine&Wave” or “B-S.Fine&Wave” is selected, the
selected Print head is further divided for printing.
Setup item Setting Description
Single head <Off> Both Print heads are used for printing.
Head1 Only left Print head is used for printing
Head2 Only right Print head is used for printing.
— • [Cancel] key: cancels the setting value and shifts to the
previous menu.

 

[Dean Dos]

Thanks for your reply.
The problem is though - Head Heat comes up at start-up, can't get into the Main Menu. Using Diagnostic mode - turning off Head Heat check, I can get into the Main Menu. Print with just Printhead 1 turned on. Send test print, acts like it is printing but not a dot fires.
Would it be that the encryption is wrong for Printhead 2 - and still sees that and doesn't fire or because the head heat is off? - Before I ran into this problem (killed original Printhead 2- printing with just Printhead 1 - it printed great.

 

[Ssignature]

When a head does not fire even one nozzle, it usually indicates a blown head fuse. When I am able this evening, I’ll look to see if the 1638 has a separate fuse for each head. When the head fuse blows, you’ll get a head temp error.

 

[Dean Dos]

I checked all the fuses on the CR Board and Main board for continuity, all seem fine. But knowing which fuse is the Head Heat 1 and or 2 would help. I just checked all the ones I could find.

 

[Ssignature]

I'll ask Mutoh on Monday.

 

[Ssignature]

Quoting Mutoh:
all 2 head machines have a head fuse for each print head. They are located behind the large, black heat sinks at the top-right edge of the main board. They are both 750ma and should be labeled as F2 (head 1) and F5 (head 2) You must remove them to check continuity

 

[bil]

Hello,

When head heat message appears at the start up of the printer it could be the head cables, maybe you haven't inserted them well, you need to check them again if you haven't replaced them i highly recommend you do it.
Because even if the fuses on the motherboard are blown, no message should appear when you turn on your printer, just the heads won't fire any thing.

Even if the head rank wasn't inserted it won't cause you this problem, and you can't also bypass this message, you need to fix this problem fist and then you can select which print head you want to use.

If you can share a picture of the new printhead it wold be great.

The message head heat can be caused by:
1- Head cables not well inserted or damaged, or if the order of the cables hasn't been respected,
2- The print head is faulty
3- The motherboard is faulty

 

[Ssignature]

While it’s true that the head heat error is often a bad thermistor in the head or a cable issue, we often see that error in the field when a head fuse blows. Sometimes replacing the fuse fixes it, sometimes it’s more extensive. On the single head printers, it’s a common occurrence.

 

[Dean Dos]

Getting somewhere now.
Replace Head 2 as I know it was damaged. Same problem (Head Heat Error) - Replaced head cables to Cr Board, Same problem - Found Blown Fuse (which I checked before and was fine, now replaced), same problem.
Disconnected Cables from CR board to the main board, inspected them, reinstalled, Boom no Head Heat Error, printer started up, did a nozzle check, only Print Head 1 fire. Prime Print Head 2 dampers, still not firing.
Though maybe the Capping station pump, as there is no ink coming from Head 2 while doing a clean. So I switched lines from Capping 1 to Capping 2 to confirm the pump, but the ink still comes from Head 1 and not Head 2.
Next, I changed the cap on head 2 of the station as I have extra here from my old 1604 (inspected it seems good and a proper match) Still no ink flows while doing a clean.
Any ideas on what to try next?
At least I can print now with Head 1

 

[Ssignature]

Each head has its own fuse. F2 and F5

 

[Dean Dos]

I have double-checked F2 and F5 - even check all the others to be certain.

 

[Ssignature]

Are you sure the ink solenoids are opening? You could exercise them in diagnostics or hold them open and pull from under the cap with a syringe

 

[unmateria]

If you bought a chinese printhead, look the printhead plate. They use glue and the first plate they get lol they dont matter if the printhead has 8 channels, they use a 6 or 4 channels plate and they just glue it to an old printhead with no injector in its place.
It can be more things (the rubber inside the printhead or a bad captop from the printhead rubber to the dampers), but if you bought it in china, im pretty sure is just that. Hope you payed with PayPal