The second AT supply is an L&C aka Allied aka Deer. Not at any price.

The distortion on the CRT might be noise back fed on the mains circuit or noise on the bus rails. Both supplies have inadequate secondary filters and inadequate to nonexistent primary filters.

That Olivetti PSU seems to be a quality unit. Nice parts.

Minebea = NMB (Nippon Miniature Bearing Co. Ltd.), mostly known for their precision bearings and keyboards.

quicknick wrote on 2020-03-24, 22:44:

That's a nice one, albeit a bit low on power. The insides look much like my Astec SA145, there's even that Astec branded chip inside, and same Nippon caps, so who knows if it's really Minebea...
Anyway, mine is built around 1994 and I've recapped it last year. I was surprised how good the 25 year old caps measured, in some cases the replacements actually had somewhat higher ESR, and I've used lowest ESR that you can find nowadays from Panasonic and Nichicon. I have more confidence in the PSU after the recap, and I'm keeping the old caps to maybe upgrade a junk PSU some day.

My PSU is from 97, but the entire computer heavily base on Olivetti Modulo line that dates back to 95, I believe. It is then likely, that they have used Astec design.

Anyway, I am also bit worried about the max power of this PSU. This is the only PSU <200W, that I am using right now. As I wrote above, I want to use it with Voodoo and AWE64 GOLD + one HDD and one CD. I have already tested this configuration for a moment (everything assembled to not to miss anything) with Tomb Raider and Quake, to push Voodoo. On the wall it gives me c.a. 65 W (IDLE is c.a. 57 W), but I am not sure if such test is sufficient to judge. What do you think?

As for the recap, I will do the same as you. Just a follow up questions 😀 Some of the caps (the large input ones in particular) are certified 85 deg C. I am thinking to swap them with the 105 deg C ones. Good idea or overkill? Also, to the best of my knowledge, I have to match the capacitance of the new caps with the old ones. But what about the voltage, can I go higher? Asking in case if I will have problems finding exactly the same spec new caps.

P.S.
Great idea about reusing old caps. I will keep them as well, and maybe tinker with my crappy PSUs, just for fun 😀

ShovelKnight wrote on 2020-03-25, 10:06:

That Olivetti PSU seems to be a quality unit. Nice parts.

Minebea = NMB (Nippon Miniature Bearing Co. Ltd.), mostly known for their precision bearings and keyboards.

Thank you for your opinion!

Seems like they dropped PSU business in 2003 to concentrate on bearings and keyboards. However, it also looks like they are right now under one of my favorites, Mitsumi 😀

The primary caps are not stressed as much as the secondary ones, so that's why they went for 85°C. Going for higher temperature rating won't hurt anything (except your wallet maybe 😁 ). Capacity should be the same, one step higher should work IMO but when recapping PSUs I always used the same value. Voltage can be higher if the new cap fits, I think bigger size translates into greater ripple capability so that's a plus for their longevity.
You should also match ESR as much as possible, search the datasheets to find the values.

That reminds me my Intertan DT-88 from which its PSU doesn't even have a dedicated case, the PCB is screwed to the main chassis and there's a cover screwed over it to avoid anyone hurting himself from tinkering with the computer.
But that's not a big surprise as it's just a 8088 machine with one hard drive.
I wouldn't describe its PSU as crap, as it was simply made for a very low power computer which isn't supposed to require anything more..

Deksor wrote on 2020-03-25, 15:54:

That reminds me my Intertan DT-88 from which its PSU doesn't even have a dedicated case, the PCB is screwed to the main chassis and there's a cover screwed over it to avoid anyone hurting himself from tinkering with the computer.
But that's not a big surprise as it's just a 8088 machine with one hard drive.
I wouldn't describe its PSU as crap, as it was simply made for a very low power computer which isn't supposed to require anything more..

That is a synonym of proprietary PSU, fully integrated into the computer 😀 BTW sweet machine!