M602 PDF direct prints garbage after firmware upgrade

[busitech]

We have 18 laser printers from HP in the company.

I installed a firmware upgrade on three M602 devices, and now all direct PDF files print square characters mixed in with the correct charaters on our documents.  The PDF files have embedded fonts.

The firmware version in the M602 is 2307851_000040 / 3.7.01 / 20160225

The same document printed to a P3010 prints correctly, with firmware 07.240.7 / 20151017

I would like to begin working with HP for a fix to the M602 firmware.

Here is a small segment of the document that printed correctly before the firmware update:

[Imagenet_Tech]

Hello, I would try changing the driver from PCL 6 to PCL 5 and see if that changes anything. From what you described almost sounds like the machine is printing windings. Is the printer printing nonstop when this happens?

[busitech]

Hello, there is no driver when using the direct PDF feature.  The server sends the actual PDF file directly to the printer via FTP.

[busitech · Accepted solution]

After working hard through the chain of command, I was able to escalate this with HP, and recently received new firmware that fixes this issue, for one of our many printers exhibiting the issue.  This is great news.  Thank you HP!