**Subject:** Need Help with HP Scitex FB550 – Magenta Print Head Not Filling

[PartyTownDecor]

Hi everyone,

I’m having trouble with the magenta ink on my HP Scitex FB550. The print head won’t fill despite trying several troubleshooting steps, and I’m hoping someone can help. Here’s what I’ve done so far:

- Replaced the magenta ink twice with two different batches.
- Disconnected the hose on both ends, cleared it by blowing through it, and reconnected.
- Purged the system multiple times and attempted to refill the print head numerous times.
- Turned the printer off and on as suggested.

Despite this, the air pump goes off about every 30 seconds, which makes me suspect there might be an air leak or could this be caused because the printhead won't fill?. I’m unsure how to locate a potential leak or if this could even be the root cause.

Any advice on how to fix this or steps I might have missed? Is there a way to identify and address an air leak effectively, or could something else be causing the issue?

Thanks in advance for any tips or guidance!

 

[greysquirrel]

the problem is the oring between the upper lower ink reservoir. Its a simple fix but also and expensive repair if you damage the unit. But before you look into that, when you engage the pump when you purge air, is the magenta pump working?

 

[PartyTownDecor]

the problem is the oring between the upper lower ink reservoir. Its a simple fix but also and expensive repair if you damage the unit. But before you look into that, when you engage the pump when you purge air, is the magenta pump working?

Hi greysquirrel,

Thanks for responding to my message! It does look like the pump is working. At one point, it even said the head was filled, but then it stopped and reported that the printhead wasn’t full.

I’m willing to try anything at this point, so I really appreciate your help. I’ll look into where I can buy the O-ring you mentioned ( please let me know if you know where to get one) and give it a try. Thanks again for your advice!

 

[Bonzai901]

It looks like the filter is clogged, possible from bad ink or just a bad hose on the new box of ink, how it did happened? can you see any ink dripping when purging? It could be the floater just giving it wrong reading, floater is inside the thermistor is a thin piece of glass and sometimes over time the rubber seal drops and make it think there is ink on the reservoir

 

[PartyTownDecor]

We just came in to find these tubes filled with ink; all the others are filled with air. We never opened this station. Does anyone have any suggestions on how to handle this? So we still have the error with the magenta print head and now we have this error with the black filling the air hoses.

 

[Bonzai901]

Looks like there’s a vacuum problem, I ran 2 FB700 for 12 years but never encountered this issue

 

[FrankW]

Is there a specific error message? if there is something like "Magenta Reservoir failed to fill" (E-FH-24), it could be a problem with the thermistors in the ink reservoir (above the head) too: there are some thermistors in the upper half of the ink reservoirs in different heights: when there are temperature differences between the thermistors, the printer "thinks" that the lowest is under liquid (ink), the higher in the air, and register it as filled. Error messages about a failed fill up can be too a problem with the thermistors (reservoir filled, but thermistors failing).

 

[PartyTownDecor]

Is there a specific error message? if there is something like "Magenta Reservoir failed to fill" (E-FH-24), it could be a problem with the thermistors in the ink reservoir (above the head) too: there are some thermistors in the upper half of the ink reservoirs in different heights: when there are temperature differences between the thermistors, the printer "thinks" that the lowest is under liquid (ink), the higher in the air, and register it as filled. Error messages about a failed fill up can be too a problem with the thermistors (reservoir filled, but thermistors failing).

Thank you for your input!

This printer is new to us—we purchased it second-hand and are still in the learning process. So far, we’ve spent about 50 hours troubleshooting. After all that time we finally found that ink wasn’t passing through the connection from the ink box to the printer. After cleaning that out, the ink is now flowing. However, the vacuum cycles with a noticeable sound every 10 seconds. I’m not sure if this is normal, but it seems unlikely.

Our next step is to determine whether this noise is expected behavior. If it’s not, we’ll work on locating the leak or issue causing the repeated vacuum cycling. It’s systematic, occurring approximately every 10 seconds without fail.

We’ve finally gotten the printer to print, but addressing this cycling issue is our priority now.

Thank you again for the insight—it’s much appreciated!

 

[PartyTownDecor]

Looks like there’s a vacuum problem, I ran 2 FB700 for 12 years but never encountered this issue

This printer is new to us—we purchased it second-hand and are still in the learning phase. We’ve already spent about 50 hours troubleshooting, and after a lot of effort, we discovered that ink wasn’t flowing through the connection from the ink box to the printer. Once we cleaned that out, the ink began flowing properly.

However, the vacuum cycles with a noticeable sound every 10 seconds. I’m not sure if this is normal, but it doesn’t seem likely. I suspect it’s a vacuum-related issue. Our next step is to determine if this behavior is expected, and if not, to identify and fix any leaks or issues causing the repeated vacuum cycling. The cycling is very consistent, occurring roughly every 10 seconds without variation.

We’ve managed to get the printer to print, but resolving this cycling issue is now our top priority.

Thank you again for your reply—it’s greatly appreciated!

 

[FrankW]

There is one Vacuum pump for all ink channels. If you have a problem with one color, it don´t seem to be a vacuum problem. It´s a longer time ago that I serviced this printers, but the vacuum can be adjusted by a little adjustment screw which can be found on the back housing near the power connector of the vacuum pump, and the correct value is shown on the display. It is a longer time ago that I serviced that printers, I do not know exactly where in the menu is the value. I hope you have a service manual.

A short "brmmmm" every 10 seconds seems not strange to me, but I do not remember exactly too.

The printer is really outdated (while it has some amazing features, for example the camera system), and parts cost a lot of money. Its surely nice to work on it and bring it back to live, but this machines can be a real money pit. I wish you luck.