T795 Error 08:04, next steps

[harleyfriedman]

Hello all,

Looking for thoughts about what the best next steps are to fix my printer.  I live in the middle of nowhere, so getting an HP tech here would be an undertaking.  I have a T795 44" poster printer.  It usually tries to start up and stops at 34%, with a message that it's shutting down and then resulting in a 08:04 error code.  When starting up, the formatter lights I and II turn on solid, then III turns solid and I starts flashing.  Usually this all happens at 34%.  Sometimes it will go all the way up to 97%, and then crash.  It did this a few months ago, I called HP support by phone, we mucked with it (see below), it didn't help, so I left it unplugged for a week while deciding what to do.  Then we plugged it in, and it worked fine again.  That was several months ago, now we're back to the same problem.

I downloaded the service manual, and here's what I've done:

1. I removed and reseated the formatter.  I also replaced the battery on the formatter (the old battery checked out a just a hair over 3V, but I replaced it anyway).

2. I tried to flash the firmware, using the full package.  It downloaded onto the printer, but then gave me an error installing.

3. I entered service mode and reset the Eprom and the HDD.

4. I downloaded the logs, which dropped onto my flash drive as a *.trb file, which I have no idea how to read.

Reviewing the service manual (and anything I can find online), the recommendation is to simply start replacing parts until it works.  Recommended are the HDD, the formatter, the interconnect PCA, and the touch panel.  Also recommended are checking "the cables", which seems somewhat vague.  The LED pattern I'm seeing isn't precisely in the manual -- the closest is Flashing / On / On for I / II / III and "off" for the touch panel, but my touch panel is on.

Not sure what to do next, or if there is anything I can do to tell me what the problem is.  I'm tempted to replace the HDD, since as a moving part it seems most likely to fail.  But if this is just a loose cable somewhere, I'd rather just find it and fix it.  Is there a way to read the *.trb file, and will it (perhaps) point me in the right direction?

[okynek]

I have exact same problem with same plotter(T795). Did you find what was wrong with your plotter?

[tabcom]

I've been down this path many times. I final figured out the solution to get the printer fixed in expensively.

[okynek]

I know you from eBay! I bought from you many parts. Thank you for all your help during the years!

What would it take to fix my DJ T795 ?