Bryan,

you find my comments written inline.

Best wishes
Dieter Doepfer

> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto: Doepfer_a100@yahoogroups.com ]Im Auftrag von bcor2fg3
> Gesendet: Samstag, 1. Dezember 2012 22:43
> An: Doepfer_a100@yahoogroups.com
> Betreff: 1 Fuses & supplies
>
>
> I just added a picture of my power supply to the photos area
> because it's been perplexing me. It is clearly the A-100NT12 old
> power supply and not the PSU2. However, the big square component
> is soldered into the diagram on the PCB that shows a big circle
> and that appears to have been designed for the PSU2. The PCB
> also has the phrase "Power Supply II" printed on it.
> I thought it was a PSU2, but now I believe it isn't and that I
> may have been overloading the supply for a long time!

There was a transition period about 10 years ago where the customers could
choose between the old version of the PSU (black block transformer, 650mA
output) and the new version (ring core transformer, 1200mA output). For both
versions the same pcb was used during the transition period as the pcb was
suitable for both transformers. From about 2004 only the PSU version with
the ring core transformer (1200mA output) was manufactured and it was no
longer possible to choose between the two versions.

> Anyway, this all started because I blew a fuse and was trying to
> figure out what to replace it with. Apparently for the earlier
> power supplies you need a 250mA 250V slow blow fuse. I've spent
> the last several hours driving around the DC suburbs trying to
> find such a fuse but have had no luck. RadioHack does carry a
> 500mA slow blow fuse. How much damage would I be risking to my
> case if I used this instead Is a 250 mA difference that much

You may use the 500mA fuse temporarily because in case of a severe fault
(e.g. short circuit) even the 500mA fuse will blow. But I'd recommend to
replace the fuse by a 250...350mA type.

> Thanks
>
> Bryan