Hello all, Long time lurker and reader here who has enjoyed visiting many VCF East and swap meet events. I am hoping the hive mind can assist me with solving a tricky problem I am having repairing a pair of HP LaserJet 4P printers. I have two HP LaserJet 4P printers, both in decent condition, and both exhibiting the same exact problem - the printer passes all self tests and everything works perfectly EXCEPT printer output pages are completely blank or have only the slightest sheen of gray toner background. Forcing an engine test with the formatter board disconnected yields the same results. I have swapped parts between printers, tried a brand new-old-stock toner cartridge in both units, and even tried replacing the laser scanner with a supposedly known good laser scanner assembly. None of these steps have worked. The service manual suggests final step would be replacing the high voltage board, but short of finding another donor printer, I haven't been able to locate one. I've reached the end of my ability to troubleshoot these units, and am perplexed that both appear to be suffering from the same (possibly age related?) failure. Can anyone here on the list offer any suggestions or help? I'd be happy to haul the printers to the next repair session if anyone here thinks they can further diagnose or troubleshoot the issue. Thanks in advance for any help! Warmest Regards, Anthony Iannone aiannone@nis.gs