[Info-vax] DS10 power supply unit

[glen herrmannsfeldt]

abrsvc <dansabrservices at yahoo.com> wrote:
> On Thursday, May 3, 2012 7:56:32 AM UTC-4, MG wrote:
>> Is there something unique or special about the Compaq DS10
>> power supply unit, P/N: 30-50454-01?
 
>> I'm asking this, because apart from being 300 watt with a
>> Compaq part number, of the AcBel brand, it appears like a
>> typical 'switching' AT/PC type PSU to me...
 
>> In case the PSU in one of my DS10s is defective, couldn't
>> I simply use any PC power supply?  (I don't absolutely
>> for sure yet, but I'm getting the strong impression.  So,
>> I'm already investigating several possibilities.)
 
>> When it comes to electrical equipment and components, I'm
>> very careful, but the reason I'm asking this is because
>> DS10 PSUs seem very expensive; even in used, second-hand,
>> condition.

> I too struggled with the pricing of the supplies.  
> I was fortunate to locate a few on Ebay relatively cheap 
> and was also able to repair the failed ones I had.  
> In one case, I actually purchased an entire DS10 system 
> for less than the cost of the supply.  
> Contact me via Email if you need one at a reasonable price.

> The main problem with these (and other vendor specific supplies) 
> is that the connectors are unique to the vendor.  

Easy fix, cut the one off the failed supply, splice it onto
the replacement. The color coding might be different, though,
so don't just go by that.

> The power supply itself is perhaps designed with a tighter 
> tolerance or more safety features, but overall the supply is 
> still a switch mode supply with all kinds of regulation and 
> control.  

Could be, and at the original price it might have made sense
to worry about that. But now you have to do it based on current
prices for machines and power supplies. 

But first the replacement has to fit in the box, or else you
have at hanging outside.
 
> THe failures I have seen thus far have been relatively simple 
> to fix.  Please note that these repairs are not typically 
> DIY repairs.  I have been in the repair business for a 
> long time and these are not new to me.  Parts are getting 
> a bit difficult to locate outside of larger suppliers that 
> require minimum purchases either by count (1000 pieces) or 
> by $$ ($300-$500 purchase).

Many years ago, I had to have someone (department electronics
shop) repair a switch-mode supply. As I remember it, there is
a Schottky rectifier of very high current at the output, and
that one had failed. It might be that the switch transisitor
also had failed, possibly driving into the failed recitifier.

But these days, I would not be surprised if the failure
was in capacitors. That seems to be the favorite mode
for everything. 

-- glen