fan speedup-power supply question
Steve Urich
beyo at beyonet.UUCP
Fri Jun 14 03:05:11 AEST 1991
In article <1991Jun12.125517.9615 at news.gvl.unisys.com> derekp at gvlf9-m.gvl.unisys.com () writes:
[Fan stuff deleted]
> 2. The power supply: The one I bought was marked
> Power Systems: pn PS-1569
> 5v/20a 12v/3.5a -12v/100ma.
<*> This is a PC-7300 195W PS. -12v should be 300ma.
> Power Systems: pn PS-1610-1
> 5v/20a 12v/5a -12v/300ma.
<*> This is a 3b1 2meg motherboard PS at 245w.
From what I can see the difference between the 2 PS's are as follows:
PC-7300 195w UNIX-PC 245w.
----------------------------------------|------------------------------------
Q1: JE8503 | MJ12005 /w larger Heat Sink
R6: 1.5k @ 2W (2W guess) | 1.5k @ 5W (5W guess)
C102,103: 470uF @ 50v (BOTH) | 10000uF @ 6.3v (BOTH)
Q101: 1 less Heatsink | 1 added Heatsink
CRB101: 30CTQ030 | MBR3035PT
C111: 470uf @ 50v | 2200uf @ 25v
The above info is from looking inside my 3b1 and my pc-7300. This
was a visual only comparision. I don't have any prints for these
units.
NOW!!!! If only someone with Repair manuals can identify these
parts then everyone could upgrade there pc-7300 PS :-). For the
Q101 Heatsink you could use the black side of the old Q1 sink :-).
Then someone would be able to start a group upgrade with the correct
info for all those wishing to upgrade there PC-7300 PS for RAM,HD's
more Boards, etc UPGRADES.
Steve Urich
WB3FTP
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