Designjet 500 magenta head issues

[printlessguy]

Good Morning all and thanks for help and ideas in advance.
I have a client with a DJ 500 42" that was having a black printhead error saying to replace it. looked at all heads dates and found all out of warranty by 6 - 8 years. ordered a new set. all came in with exp date of 2020. before replacement. all but the black were recognized and working. replace heads. Black , yellow and blue are fine magenta fails imediately after close lid carriage gos towards station to do drop tests machine beeps (sour note) and says bad magenta. cleaned contacts in carriage ( yes machine was off) no joy. get replacement head still no joy. update firmware no joy. put original expired head in recognized and calibrates fine. and prints fine too. any thoughts? carriage? station? trailing cables? shouldnt be drop detector since the others work.
thanks for your insight
Andy

[theengel]

Re: Designjet 500 magenta head issues

I don't know how many times you tried the magenta printhead, but sometimes you have to pull them out and reseat them a few times before they work. And I hate to tell you this, but sometimes a bad printhead will cause the machine to say a DIFFERENT printhead is bad. So when the carriage pops out, pull ALL the printheads out, clean all the contacts with a damp rag (water works best, and I usually do this with the machine still on... some people might warn against that, but that's how I've always done it) and put all the printheads back in. Then, do it again.

It's not out of the realm that two magenta printheads are bad.

Also, you don't have to worry about the exp. date. Expired printheads usually work fine.

If it absolutely won't work (but then, since the old magenta works, I can't see that) then the next thing to replace would probably be the flex cables... maybe the trailing cables at the same time, but I would think it's more likely to be flex cables.

To tell you the truth, after trying one more set of printheads, I personally would tell the customer:

The parts on this machine are just old and worn, and we're putting new and old parts together to try to make it work. To do this right, we should just replace the carriage and trailing cables together.

On a 500, this isn't terribly expensive.

[Phil B.]

Re: Designjet 500 magenta head issues

I don't know how many times you tried the magenta printhead, but sometimes you have to pull them out and reseat them a few times before they work. And I hate to tell you this, but sometimes a bad printhead will cause the machine to say a DIFFERENT printhead is bad. So when the carriage pops out, pull ALL the printheads out, clean all the contacts with a damp rag (water works best, and I usually do this with the machine still on... some people might warn against that, but that's how I've always done it) and put all the printheads back in. Then, do it again.

It's not out of the realm that two magenta printheads are bad.
Also, you don't have to worry about the exp. date. Expired printheads usually work fine.
If it absolutely won't work (but then, since the old magenta works, I can't see that) then the next thing to replace would probably be the flex cables... maybe the trailing cables at the same time, but I would think it's more likely to be flex cables.
To tell you the truth, after trying one more set of printheads, I personally would tell the customer:
On a 500, this isn't terribly expensive.

not to mention that it will be HARD to find parts for that model. I had to give the bad news to one of my customers just the other day!

[Kiran Otter]

Re: Designjet 500 magenta head issues

theengel said everything exactly as I would have. You may very well have 2 bad, new magenta printheads. And the carriage and trailing cable are readily available from either LPS Computer, or even HP.

If you do replace the trailing cable, you will likely have to transfer the 'foil' (it's the stiffener/plastic strip that keeps the trailing cable's shape) from the old cable to the new. Without it the cable will get damaged by the carriage. HP used to include it, then they didn't for whatever reason. And the cables you get from LPS will be generic ribbon cables, so you have to do a little work to refit them with the stiffener. I recommend using duct tape (I use book binding tape) to tape it together, not electrical tape.

Kiran

[printlessguy]

Re: Designjet 500 magenta head issues

thank you all for your input. I will give the client the information and see what they want to do. since they predominantly print b&w it is not to much an issue but will see where this goes.
thanks