Bad ripple on -12 V rail of recapped Macase MG-300EP: should I worry?

[tj2]

This week I replaced all the Fuhjyyu capacitors in my Macase MG-300EP 300 W AT style PSU. The operation apparently was a success, though today I got curious and put the PSU on the scope to look at ripple. All rails are in spec on the voltage and +5 and +12 had reasonably low ripple. However, the -5 V rail has a bit more than 1% ripple and the -12 V rail has terrible ripple: more than 3%. Here are my results

 Nominal Actual  Ripple (p-p)
  +5 V +5.19 V  15 mV 
 +12 V +12.00 V  65 mV
  -5 V -4.87 V  60 mV
 -12 V -11.53 V  400 mV

I've read that few devices use -12 V, and though my components are all from the 1995 or newer, I'm still worried. Now I'm going to check the individual PCI and ISA cards for connections to -12 V. (On PCI -12 V is the first pin on the component side and on ISA it's the 7th pin in the solder side. Pins are counted from the back of the computer.) I didn't write it down, but I recall that the spikes come every 17 ms or so, corresponding to 60 Hz. Now I'm kicking myself for not measuring the ripple BEFORE the recap. I decided to recap because the PSU is from 1996 (and still in use) and all the caps were Fuhjyyu.

So, is there reason to worry?

[linuxguru]

Re: Bad ripple on -12 V rail of recapped Macase MG-300EP: should I worry?

The -12v rail rarely has any load on any modern PC - it's only used on serial cards that exactly implement the original RS-232C electrical specs (like ISA cards on the original PC/XT and AT) and occasionally by soundcards that have an onboard chipamp (relatively rare today, and they generally use only the +12v supply).

In both cases, the 400 mV ripple is largely irrelevant.