Re: AT cases, PSUs, and builds--are they really as hard as I've heard?

Posted on 2020-08-10, 21:56

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Right, I also never understood the purpose of full tower AT cases, although I remember thinking at the time they would surely be used for housing some sort of super powerful computers because bigger = better. The only advantage I can see now is the increased number of external 5,25" drive bays, …

---

Re: Testing capacitors in circuit

Posted on 2020-08-10, 16:12

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

And that's where my opinion differs. If I want to fix equipment, I am primarily interested in whether high ESR in causing the problems I'm currently seeing, not whether every single capacitor is fine. The first question can usually be answered well enough by in-circuit ESR measurement (granted, …

---

Re: List of rarest PC soundcards

Posted on 2020-08-10, 03:39

by

by gdjacobs

in Marvin \ Sound

in Marvin \ Sound

hard1k wrote on 2020-08-09, 22:27: It is indeed. I have one 😀 You or Artex could just list your collection. /thread

---

Re: Testing capacitors in circuit

Posted on 2020-08-10, 03:38

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

mkarcher wrote on 2020-08-09, 23:20: If you could force them into a " capacitor" mode, they would possibly work well enough. It won't because in circuit measurements won't show you if a capacitor has a higher ESR. It'll show you if at least one of the parallel legs of a circuit has a low ESR. Not …

---

Re: Testing capacitors in circuit

Posted on 2020-08-09, 22:36

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi, I've got quite a few old computers from the 1990s whose capacitors are obviously now rather mature. My soldering skills are adequate but certainly amateur. I was looking at LCR meters to check the capacitors on the boards to identify ones that are near failure. I dont really want to replace all …

---

Re: Replacement capacitor recommendation

Posted on 2020-08-06, 14:34

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Sanyo no longer manufacture capacitors. Their capacitor group was spun off as Suncon and remain good. Taicon are a Taiwanese brand that partner with Nichicon. They're the next best thing to the tier one brands, although they're generally only available through OEM channels. I have to stress again, …

---

Re: Replacement capacitor recommendation

Posted on 2020-08-06, 02:46

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Panasonic FR are an excellent line of caps and can be used as replacements for a lot of low ESR VRM filter applications. YXF series can be used interchangeably with Panasonic FC and Nichicon PW for general purpose applications. They're used quite a lot on PSU output filters. However, mapping and …

---

Re: Something wrong with AT PSU - hissing noise and not powering on

Posted on 2020-08-05, 15:51

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

A simple test you can perform with a true RMS multimeter (with enough bandwidth): measure AC voltage on the +5V and +12V outputs to get a figure for ripple.

---

Re: Voyager probes 40th anniversary

Posted on 2020-08-04, 22:45

by

by gdjacobs

in Milliways

in Milliways

Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn. Cthulhu 2020! Why vote for the lesser evil?

---

Re: Types of capacitors to recap computer stuff (motherboard and PSU)

Posted on 2020-08-04, 03:01

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

All else being equal, reduced ripple is always better as it translates into reduced heat stress and improved service life for semiconductors.

---

Re: Types of capacitors to recap computer stuff (motherboard and PSU)

Posted on 2020-08-03, 18:02

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

My applications: is to rebuild PSUs: this will be compaq proprietary PSUs to safeguard against blowing up, and one of my generic baby AT PSU. I also ordered 2 Astec baby AT PSUs and they tend to be well built. I wouldn't use poly caps for this, unless you're working on a more recent PSU. You'll …

---

Re: Types of capacitors to recap computer stuff (motherboard and PSU)

Posted on 2020-08-03, 17:08

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Replacing HM, HN, and KZx series with poly caps is really the only option now. Panasonic FM series and low ESR caps with similar specs can also be replaced (for ex with Panasonic SEQP, SEP, or UCC PSA series when used in high frequency switching applications, like a VRM filter). This is generally an …

---

Re: Types of capacitors to recap computer stuff (motherboard and PSU)

Posted on 2020-08-02, 01:55

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In nearly all cases in Switching Power Supply Units/Circuits the function of the Electrolytic Capacitors are for filtering (minimalizing the AC ripples on the DC voltages). As higher the current, as lower the needed amplitude of the AC Ripple, as highe r the needed capacity. The power dissipation …

---

Re: Types of capacitors to recap computer stuff (motherboard and PSU)

Posted on 2020-08-01, 02:11

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Polymers work well in general when they have an ESR which matches well with the low ESR caps they're replacing. ESR is the determining factor for output ripple and capacitance isn't very important in such cases. Ideally we'd be able to swap every output filter cap with polys and get cleaner power, …

---

Re: Bought these (retro) hardware today

Posted on 2020-08-01, 02:02

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

pete8475 wrote on 2020-07-31, 15:21: hahaha Alright guys I'll grab it next time I'm there. I've never been great with a soldering iron but I guess I'll make a thread about attempting to repair that board when I have it. "You know how to get to Carnegie Hall, don't ya?"

---

Re: Technological critique

Posted on 2020-08-01, 01:53

by

by gdjacobs

in Milliways

in Milliways

dnewhous wrote on 2020-07-31, 17:51: Oh, like Lisp? No. LISP isn't a prime example of functional programming as it allows the use of a wide variety of paradigms. I believe Scheme (a LISP subset) is, though. ML (and family), Haskell, Ruby, F#, and Erlang are all modern languages that require the use …

---

Re: List of rarest PC soundcards

Posted on 2020-07-27, 15:22

by

by gdjacobs

in Marvin \ Sound

in Marvin \ Sound

Does the PCjr count as a sound card?

---

Re: Cd rom audio

Posted on 2020-07-27, 02:27

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The Sony/MPC2 connector is RGGL, so reversing the connector reverses stereo. Mitsumi is RGLG, so you'd have a reversed voltage into header. Your SB Pro is probably NLGR (where N is non connected), so reversing the connector would at least null one channel. I would expect the input impedance to be …

---

Re: 1997 Pentium MMX Rebuild

Posted on 2020-07-26, 00:45

by

by gdjacobs

in Marvin \ System Specs

in Marvin \ System Specs

Some Socket 7 boards allowing using FSB or multiplier jumpers' pins as Turbo button pins. So the button can be connected instead of those jumpers and it will work. Here is my MB layout: https://i.imgur.com/XJCpfPvl.jpg I don`t see how to connect it... To use 386 speed in bios disable CPU and …

---

Re: A tale of two PSUs

Posted on 2020-07-26, 00:15

by

by gdjacobs

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The codegen should be used only for parts. It has absolutely no input filtering, this means that the EMI/RFI noise coming from the mains will pass on the output voltages and could cause issues with the computer operation, especially the sound card and the opposite, any electrical noise caused from …

---