My CPU board (for a Mac XL) reads: 419 2 N 5771
Both Q1 and Q2 are identical. Hope this helps. On Friday, May 3, 2013 6:09:44 PM UTC-4, Notgoing Totellyou wrote: > > thank you for that great information! > > Can anyone look at their lisa cpu board and let me know what you have in > that spot? > > Thank You! > Charles > > > > On May 3, 2013, at 6:01 PM, Doug McNutt wrote: > > > At 12:56 -0700 5/3/13, Notgoing Totellyou wrote: > >> I have the CPU card here and its missing a transistor. > >> > >> i can't find a replacement anywhere. > >> > >> Anyone have any lisa parts laying around? > >> > >> it reads : AMPS 4258 EBC > >> > >> you can see the spot behind it, it's missing . > >> > > \ > > Transistor Data Book edition 48, 1980 > > > > MPS4258 CRI, SPS, MOTO p 153 line 15 which says: > > > > Silicon PNP low power > > 350 mw collector dissipation > > V cbo 12 V > > Collector max 800 mA > > Hfe (gain) 15 > > > > > > I would recommend a very common 2N2907 as a replacement. > > > > From the picture it's not altogether clear that transistors Q1 and Q2 > are supposed to be the same type.. A pretty common circuit uses PNP and NPN > pairs close together. The pair to the 2N2907 is NPN type 2N2222, also very > common. (I have a bunch of both here. Use dmcnutt at above off list with > Lisa somewhere in the subject.) > > > > A look at a working Lisa would be worth while. Anybody here ?? > > > > I also have no idea what the A in front of the very common Motorola MPS > means. > > > > > > -- > > > > Fe++ > > // \ > > Fe++ Fe++ > > | || > > Fe++ Fe++ > > \\ / > > Fe++ > > > > -- > > -- > > ----- > > You received this message because you are a member of the Vintage Macs > group. > > The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our > netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml > > To post to this group, send email to > > vintag...@googlegroups.com<javascript:> > > To leave this group, send email to > > vintage-macs...@googlegroups.com<javascript:> > > For more options, visit this group at > http://groups.google.com/group/vintage-macs > > > > Support for older Macs: http://lowendmac.com/services/ > > --- > > You received this message because you are subscribed to the Google > Groups "Vintage Macs" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to vintage-macs...@googlegroups.com <javascript:>. > > For more options, visit https://groups.google.com/groups/opt_out. > > > > > > -- -- ----- You received this message because you are a member of the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to vintage-macs@googlegroups.com To leave this group, send email to vintage-macs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/vintage-macs Support for older Macs: http://lowendmac.com/services/ --- You received this message because you are subscribed to the Google Groups "Vintage Macs" group. To unsubscribe from this group and stop receiving emails from it, send an email to vintage-macs+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
