HP Forum Archive 14

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Printer repair Message #1 Posted by David Ramsey on 8 Aug 2004, 12:46 a.m. I have an 82162A printer that is failing to print a couple of pixels-- any printout has horizontal white lines through it. Is this something that might be due to a loose contact that could be repaired? Or is it a bum printhead?

Re: Printer repair Message #2 Posted by Vieira, Luiz C. (Brazil) on 8 Aug 2004, 2:06 a.m., in response to message #1 by David Ramsey Hi, David; are you well? Both possibilities are valid. I am not completely aware of how is the HP82162A (HPIL standard printer, right?) head connection, but it seems to me it is not too different of the one found in the HP82143A (HP41 standard peripheral printer). The 82143A has a flat circuit connecting the printer head to the mainboard. The connection is achieved by some sort of "metal clippers" that firmly hold the fex edge to the mainboard connector. I used a small piece of nonconductive, ESD "aware" plastic to "produce" a small clearance between the flex circuit and the "clipper" connectors (Gee, I hope yopu can read this and understand... where are the English terms when I most need them?) so I could remove it. I'd guess: (the order does not mean "preference" order or the like) 1 - cold, broken soldering; 2 - bad connection; 3 - broken cooper trail in flex circuit (today this is easy to repair); If none, maybe (just maybe) either the printer head or one of the drivers (some 8-pin DIP guys closer to the head connector) are bad. I'd not take this last possibility as the most likely to be because you mentioned there are "some" blank horizontal lines. I'd not go for more than one burned driver or head thermal dot (resistor). At least I'd not. Anyway, other printer experts (or gurus) surely will give you better guidance. Hope you succeed. Luiz (Brazil)

shim Message #3 Posted by Cameron on 8 Aug 2004, 4:20 a.m., in response to message #2 by Vieira, Luiz C. (Brazil) Luiz, what you describe mught be called an "anti-static plastic shim". Cameron

Thanks! 8^) Message #4 Posted by Vieira, Luiz C. (Brazil) on 8 Aug 2004, 11:00 a.m., in response to message #3 by Cameron Hi, Cameron; thanks! Sometimes my "foreign language" vocabulary is simply not enough! I thought about "slice" or "cut", but I was almost sure it would not be "as good as". Best regards. Luiz (Brazil) Edited: 8 Aug 2004, 11:27 a.m.

Re: Printer repair Message #5 Posted by David Ramsey on 8 Aug 2004, 9:03 p.m., in response to message #2 by Vieira, Luiz C. (Brazil) Luis, Yes, I'm fine...except for this printer. I see the area you mention. The flex cable is folded into a shallow "V" and pressed into a connector on the logic board. I inserted a paper shim in the "V" and plugged the flex cable back into the connector, but it didn't make any difference. I suppose the next step would be to remove the logic board and resolder the connections of the connector that the flex cable plugs into...

If... Message #6 Posted by Vieira, Luiz C. (Brazil) on 8 Aug 2004, 10:01 p.m., in response to message #5 by David Ramsey ... you have another printer, that would be also another way of testing. I'd either guess an HP82143A printer has compatible printing components (head, mechanics, etc.). If you have a component source, like a trashed printer (the only source I can think of), that would be a possible solution. At least for testing and being sure about the cause. About removing the logic board: to remove the HP82143A logic board there is no need to remove the printing mechanics assembly, just unplug the wires (I cannot help laughing everytime I see the "öut-of-paper sensor" inscription: OOPS) and flex circuit, but I don't know if the 82162A also eases the job. I remember needing to remove about five screws, if not more than that, to release the board. Be aware of the ON/MODE switch lid contacts, they "tend" to be in touch with the logic board because of the (silicon?) grease used to smooth their movement and maintain surface integrity. Success! I'd like to help some more, but I think this is all I remember. Best regards. Luiz (Brazil)

Re: Printer repair Message #7 Posted by David Smith on 9 Aug 2004, 11:53 a.m., in response to message #1 by David Ramsey Your printhead is almost certainly bad. Check the resistance of each pixel with an ohm meter. Two pins are tied together (common). The other pins are the dots. Should be around 100 ohms each.

Re: Printer repair Message #8 Posted by David Ramsey on 9 Aug 2004, 8:17 p.m., in response to message #7 by David Smith David, I assume you mean that I can test the resistance at the end of the flex cable, where it plugs into the logic board. Which connectors are the grounds? The outside ones?

Re: Printer repair Message #9 Posted by David Smith on 10 Aug 2004, 12:53 p.m., in response to message #8 by David Ramsey The grounds are together at one end. They will have zero ohms of resistance between them. On most flex cables it is obvious that they are connected together.

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