|There you are!|
Message #2 Posted by Vieira, Luiz C. (Brazil) on 6 Jan 2003, 10:12 p.m.,
in response to message #1 by Frederic
it seems you have a short-circuited current booster OR a burnet-out head "driver".
If you have paper in the right position and pull it up a little, you'll probably see a vertical black line right ounder the middle of the head (the burners are there). If the current boosters are shortened, almost all power supply is over the head burners (do not let the printer ON or the head will be definitely lost), what explains the ZZZZ (from the power supply) and the "there's_something_hot" smell.
If you want to try, open the printer (five screws, one under each rubber feet and another close to the battery compartment) and carefully detach the flex circuit connector that connects the printer head to the mainboard (there is only one flex circuit). You must use something to move the conector's contact (mainboard) away, because they "pinch" the flex circuit connector tabs. I use a small antistatic piece of plastic so it fits between the contacts and the flex circuit connector. I push it in and carefully pull the flex circuit connector, then I pull the plastic out.
Then you can briefly switch the printer ON and simply verify if the BATT LED is off and only POWER LED is ON. Take care not allowing the flex circuit to touch other components and do not attach the printer to any HP41 door.
I can have a look in my 82143A and try to identify the head components, but you should also wait for other posts to help more.