I know I'm Late to the Party, but here's what I have on my ACTUAL RUNNING EXPERIENCE with the Karat 74 presses. I've been running then since 2008, so I have over 10 years of experience. Our first one was a 2000 non coater press, refurbished by KBA (originally a red press, repainted blue in refurbish), and installed by them. 2 week training with a KBA tech (I ran a QMID 46 before this press) , so I was already familiar with the direct image to plate tech. Ran that press HARD!!! There were electrical issues here and there, had a couple contactors- heavy duty relays- crap out-I replaced those, had the Baumuller Power Drive (Controls power distribution to rotate the plate cylinder motors for imaging independently, or the main drive for printing a job) crapped out too. It had a bad solder connection on a 24 volt pin that I repaired. Had a chiller that sprung a leak in the Condenser, so I had to pretty much disassemble the whole chiller to put in a new condenser. That thing is about 7 feet tall. Also had to replace the pull fan for the chiller. My work had a POS IR dryer that was installed in the press. It was essentially 15 1000 watt halogen bulbs in an array that would get so hot that they would burn out the contact tips from powder contamination and melt the holders for the tips. I replaced all the holders and tips, but when I did I put small washers behind all the tips to spread the heat and reset it to the correct distance for the bulbs. Also I put silver conductive grease on the bulb terminal ends to keep power out and have a better electrical connection. Worked great after. Had a water pump for the main circulation go out- that one was under warranty, and had replaced most of the water pumps for controlling temps on the annilox rollers and the valves to allow flow.
The 2nd KBA 74 Karat is a 2004 coater press that the company sent me out to demo to see if we should get it. They sent me to Texas (we are In Arizona) to check out a coater press. The guy starts up the press, gets into start up, and the computer restarts. After it restarted and stayed on I knew what the problem was when I looked at the Window screen clock. The time was wrong (In the press dialog it shows you errors by time that they occur) It was a bad CMOS battery that didn't have current time so it got confused and restarted the computer. I Went in to the CMOS and set time and date for the demo, and there was no restart- so I knew it was just the battery. With the demo I wanted to see how to set the coater up, and how to tear it down. We got that press in 2016, replaced our non coater with it, I did most of the rewiring myself. The non coater went to pasture for parts. BTW some parts are compatible between the 2 models, some aren't.
BTW 3~ months after the coater press was installed- they gave me a job that they wanted to have soft touch coated. Man, I wasn't trained in this- I only saw it that one time. I KILLED IT!!
SO- Karat 74's do have some electrical issues from time to time, I do my own press diagnosing, most repairs, and printing to boot. - And I know where the parts are
Now on to the weirdness of the internals of these presses- for starts- if you get a non converted press- Presstek is no longer producing the original plates for this press. Verico is now dealing with the plate manufacturing, the plates are thinner aluminum, so you have to have a thicker foil on the plate cylinder to make up the distance to be able to image. Use to be a Presstek pearl dry 74, but now you have to go with a Zahara K74. With this press you have to have the right height of the plate on the cylinder for it to burn in properly. Even a little crap ( last job was picking) that fell in under the plate distorts it so that area isn't at the proper height for imaging. Then you have to remove the plate, clean the cylinder, load another plate, and reimage. Some of the boards in the Operating system(in the computer encloser) for Imaging- KBA wants about $10,000 to replace those. I've seen the boards they have sent out when trying to figure out an issue we had before and there were wires hot glued in place on the back sides of the board, and I was never a board issue that I had.
Keep your annilox rollers clean, fresh ink and new blades in your heads, and your cams and chains lubed up- then your half way there.
Also anyone that needs Karat 74 info- Just Email me -
[email protected]