[Coladam] Q-Paq Decoded
lst2001 at bresnan.net
Fri Jan 30 21:50:06 CET 2009
Recently I obtained a nonfunctioning Adam console, so I had an opportunity to get a couple of Q-Paqs. Since some months back I asked if anyone knew what they were for; and no one was really sure what they were. My best guess was they were heat-sinks, someone though they might be capacitors or something else. Well I was sure they were not capacitors since when I tested continuity it looked like ever pin was open.
The reason I felt they wouldn't be capacitors is there already were caps between +5v and gnd. So why more? Second I used digital meter to test continuity so I missed the charge bounce I would have seen if I was using an analog meter.
Well, I disassembled one of the Q-paqs (see attached file). And yes it is a heat sinks. Also its construction makes it a capacitors I took the one I had not taken apart and measured its capacitance at .076uf, a rather small value.
Okay, so why did they fell a heat sink was necessary? I place a thermo probe under the PROM U22, turned on the computer and let it sit for 4 hours. I measured a temperature that was 21 degrees higher than room temperature. I did the same for U20 and U21, with temperatures 17 and 31 degrees respectfully above room temperature. None of these temperatures come close to exceeding the recommended operating values for these PROMs under normal room temperatures. So this looks like a bit of over kill to me.
Well that what I've learned about the Q-paq. Hope the information is of interest or useful to someone, other than me.
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