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HP Forum Archive 19

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HP 9845A vs 9845B vs 9845B/A
Message #1 Posted by Mike on 22 Aug 2010, 10:51 a.m.

I have a very nice and nearly perfect 9845A. The printer is the only thing less than ideal. A few of the dots are not working (in just one area).

I bought a junker 9845B, in hopes that between the two, I could get my printer back to 100%.

When the 9845B arrive, it was marked 9845B/A. The A was hand labeled. Also, the ROM drawers have Brown and Red colors, which is what was used on the "A". And they have the OS in them. I believe the B has them internal and not in ROM drawers.

Is this likey an in between model. Or is it more likely that they keyboard might just have been swapped and remarked to show that it's actually an "A".

There is no monitor on the new unit so I can't really test it. I hesitate to put my great 9845A monitor on it, for fear that something might damage my nice monitor. I tried typing PRINTER IS 0 and then typing something on the keyboard, to see if the printer works. But I get nothing. It might be because the monitor is missing. Anyone know if the monitor being removed will keep the 9845 from starting and running (minus the display however)?

Anyone familar with these, to know what might be going on here, with the B/A lableing? I don't have time to disassemble it just yet.

Edited: 22 Aug 2010, 10:54 a.m.

      
Re: HP 9845A vs 9845B vs 9845B/A
Message #2 Posted by Tony Duell on 23 Aug 2010, 4:44 a.m.,
in response to message #1 by Mike

To answer the last part first, I believe you do need a monitor on a 9845 for it to work. There is some synchronisation signal sent back from the monitor, and the processors get somewhat confused without it. HP actually made a 'turnon fixture' for the 9845 (I am not talking about the one for the colour monitor) that would allow you to power the machine up without a monitor for testing. Good luck in finding that!

I don't know the 9845A very well (not having got one), but AFAIK the easiest way to tell the -A from the -B or -C (the latter 2 are very similar) is to remove the cover (it takes a few minutes max) and look at the processors. If you have a PCB with 2 HP hybrid processors (in the big metal heatsinks nicknamed 'Honda Heads' :-)) on one PCB it's a -A . If you have the 2 processors on separate PCBs, one at each side of the machine, it's a -B or -C. And if you have just one hybrid processor module on a PCB at the left and a set of 3 PCBs connected by a little backplane on top at the right, then you are lucky enough to have a -B or -C opt 200 (high speed language processor).


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