DesignJet T770 stuck in Initialisation

[MA_Automation]

Our DesignJet T770 started having some 21:13 errors (service module related, requesting a restart) a few days ago. Switching off via button at the panel did not work. It simply did not react. We pulled the plug, waited the usual 10-20 seconds and put the plug in the socket again. The printer started up fine, but the error popped up at least once a day.

Today in the morning we shut the printer down, waited, powered it on and it got stuck during the initialisation phase (sand clock stopped rotating). After 10 minutes without any noticable change we decided to shut it down and have some internet search.

service station looks fine and operational, all internal plugs seem to be connected (expected loose connectors from vibrations)

decoder stripe is clean (hint from the hp support hotline)

sledge is being held in place when i try it moving while powered, and moves easily when unpowered

i found some manuals to reset the nvram (which help in some cases) of other hp printers, but sadly not for the t770. Can anyone help me out here?

[Valsimot]

Have you removed a right cover to examine the movement of service station during startup of a printer?

[MA_Automation]

I moved the print head to the left before powering the printer, then lifted the top cover and pushed the "cover closed" button with a screwdriver. I could definitely see some vague movement in there, but I actually don't now how it is supposed to look like. I did remove some covers on the right side, but they did not give any useful insights at all.

Also, the printer definitely worked in between the initial error messages (we printed some drawings), I guess I did not mention that earlier.

[Valsimot]

You have a random service station failure, without disassembling and inspecting service station for proper operation it's hard to tell anything. It could be something minor like a piece of paper leftover blocking the propper movement of a service station or something major like service station motor or gears that need to get professionally repaired or service station replacement.

[MA_Automation]

@Valsimot: I know, and that's also exactly what the support hotline told me. But HP does not support this product anymore so they refuse to send a technician.

I was told to use the HP reseller search to maybe find a reseller that can help, but none so far could help.

[Valsimot · Accepted solution]

If you are handy with tools you can buy a new service station and replace it by yourself. You can buy them on eBay search for CH538-67040 and service manual with detailed instructions for replacement can be downloaded from the internet.

https://shared.swissparts.ch/Manuals/HP/Plotter/HP%20Designjet%20T770%20and%20T1200.pdf

Wish I could help you more if you have any question ask.

[meat1820]

Do you have a service manual for your printer? If not you can do a google search and download a PDF file of the manual.

Page 61 and 62 of the manual shows description of error code 21:13 and you should try the following first.

System Error: 21.1:YZ
Problem Description: Failure moving the Primer Motor of the Service Station
Corrective action: Try the following:
1. Remove the Right Cover and make sure the cables from the Main PCA to the Service
Station are connected and are not damaged.
2. Perform the Primer Motor diagnostic test (listed under the service station diagnostic test) to
troubleshoot the problem further. See Primer motor on page 123.
3. Replace the Service Station. See Service Station on page 367.

Good Luck

please report back what you find

[MA_Automation]

Yes I did some google-stuff and found some manuals, including your error code table and solutions.

But the printer doesn't boot into diagnose mode because I cannot shut it down via button on the user panel. The only way to turn it off is to switch the power supply off. Switching it back on it automatically starts and does not go into diagnose mode even though i keep holding UP and OK.

I also cannot connect to it via ethernet. I can ping it, but it does not respond to browser or ftp

[MA_Automation]

Small update:

I updated the firmware (it was probably still on some 2011 version) and it initialises again, but again getting the 21:13.

(I suppose powering the printer off repeatedly by pulling the plug did some software damage, but it did not react to the button on the front panel, so there was no other way)

Finally found a description on how to remove the whole right cover and remove the service station. Scraped off lots of very gluey and partially crusted ink residue from basically everywhere. I feel like the ink is not supposed to go between the gear and the serrated shaft on the bottom of the carriage?

The carriage does drive part of its way but seems to be stuck on the last maybe 2 cm to the front. Will repeat on monday and give that thing a more proper cleaning.

Worst case we have to buy a "new" service station from ebay and hope for the best.

[Valsimot]

You have done a good job for now.  Try to clean service station as best you could check worm gears and motor the can go loose and if there is a small resistance motor rotates but worm gears stay in place, a small amount of oil to lubricate middle part of the service station that moves on plastic rails.