Re: Profile gotchas

[Peter Ibbotson <pibbotson@gmail.com>]

On Thursday, 9 May 2013 23:43:23 UTC+1, Michael J. Mahon  wrote:
> Peter Ibbotson <pibbotson@gmail.com> wrote:
> 
> > On Wednesday, 8 May 2013 19:47:51 UTC+1, Michael J. Mahon  wrote:
> 
> >> Peter Ibbotson <pibbotson@gmail.com> wrote:
> >>> I've just moved into a new house, so now it's time to setup the retro
> >>> computer museum now I have space for stuff that's been in storage. 
> >>> 
> >>> I have an 5Mb profile drive that I'd like to fire up, I seem to remember
> >>> that if the power supply has bad caps this tends to also take out the analog board.
> >>> 
> >>> So is there a recommended order for bringing Profiles back into use after
> >>> storage? i.e. should I disconnect the PSU portion of the profile, put
> >>> some load on and try powering up the PSU?
> >> 
> >> This is an excellent procedure, since the power supply is the most likely 
> >> location for electrical issues. 
> > 
> > Sadly it all went horribly wrong... Smoke from the PSU I'll investigate
> > properly at the weekend.
> > 
> > Peter
> 
> If the smoke is from the large electrolytics or diodes near the mains
> connection, then either one was bad and took out the other. Both the cap(s)
> and the diodes should be replaced. 
> 
> I'd the switching driver is shorted, it could take out the diodes or (hope
> not) the primary of the toroid transformer. 
> 
> Hopefully it's just the mains side supply and no more. Those large filter
> caps tend to lose their voltage rating (forming) with time, and could have
> caused big overcurrent when turned on. 
> 

On the plus side VintageMicros have spare power supplies so if it's not repairable I may jury rig something from bench PSUs and then order if the rest of it works.

I have a euro plus that needs a new PSU, a couple of //e and a //c that I've still got to check out. So I'm just hoping that the Profile was my "bad luck" PSU.

Peter

Peter