GigAHerZ wrote on 2024-02-17, 10:27:

It's an overkill that actually works worse. Fans (or any DC motor), just like LEDs, would prefer full 12V (LEDs with their appro […]
Show full quote

dominusprog wrote on 2024-02-13, 21:38:

Changed the fan for this power supply and I'm very happy with it, except the noise which is around 40dB. So I put a buck DC/DC converter between the fan and the power socket. Now it work at 7V.

IMG_20240213_201117.jpg

It's an overkill that actually works worse.
Fans (or any DC motor), just like LEDs, would prefer full 12V (LEDs with their appropriate full voltage) and the speed being controlled by turning it on and off very fast. So it's a PWM on powerline.
In practice, it means you can achieve way lower speeds while not stalling the fan. Also you have better starting probability. (With lower voltage, the fan might easily continue to run, but may not be able to start)

In aliexpress, you can find similar simple boards that would be more suitable for this scenario. ("12V PWM" would be a keyword. Without spending time on searching, already saw some for 1€ a piece, incl. shipping.)

Find what exactly? About the fan that isn't able to start, I understand what you said but I decreased the voltage to 7V which is high enough to start the fan.

dominusprog wrote on 2024-02-17, 17:29:

GigAHerZ wrote on 2024-02-17, 10:27:

It's an overkill that actually works worse. Fans (or any DC motor), just like LEDs, would prefer full 12V (LEDs with their appro […]
Show full quote

dominusprog wrote on 2024-02-13, 21:38:

Changed the fan for this power supply and I'm very happy with it, except the noise which is around 40dB. So I put a buck DC/DC converter between the fan and the power socket. Now it work at 7V.

IMG_20240213_201117.jpg

It's an overkill that actually works worse.
Fans (or any DC motor), just like LEDs, would prefer full 12V (LEDs with their appropriate full voltage) and the speed being controlled by turning it on and off very fast. So it's a PWM on powerline.
In practice, it means you can achieve way lower speeds while not stalling the fan. Also you have better starting probability. (With lower voltage, the fan might easily continue to run, but may not be able to start)

In aliexpress, you can find similar simple boards that would be more suitable for this scenario. ("12V PWM" would be a keyword. Without spending time on searching, already saw some for 1€ a piece, incl. shipping.)

Find what exactly? About the fan that isn't able to start, I understand what you said but I decreased the voltage to 7V which is high enough to start the fan.

A different little piece of electronics that is more suitable for controlling the fans than lowering the voltage.
If you just want to lower voltage, you could just use a resistor. No need to use that fancy buck-converter. 😀

GigAHerZ wrote on 2024-02-17, 18:12:

A different little piece of electronics that is more suitable for controlling the fans than lowering the voltage.
If you just want to lower voltage, you could just use a resistor. No need to use that fancy buck-converter. 😀

or plugging fan between +5v and +12V

Got fed up waiting for the slow motion, glacial speed "musical dining tables" game to resolve, it's been going on since 1st lockdown. I was supposed to get the old solid ash, but fugly for modern tastes table down in the basement for a retro work bench, but it keeps not happening... So... nothing else to do but out fugly it 🤣 ... I mean make some other arrangement. I had stuff balanced on a couple of TV tray style fold up tables which weren't very sturdy, hard to work on.

The old desk which is under there, was sojourning in the drier bit of my tumbledown shed, it had previously seen XT-Pentium builds and meddling at around the turn of the millennium when we were in a small rental. So it feels kinda right to reuse it now. It's fairly solid. I think I only have 3 of it's drawers left now though, the empty hole might get a hidey slidey tray setup for quick change project space.

If I were describing the top on an interior design blog it would go "Upcycled distressed artisanal barnboard surface with vintage charm" but yeah it's a door off an old shed or something. It's something I can pound on a bit, lightly scorch maybe, without giving a crap. I was intending to cover it with an old roll of linoleum... I nailed the edge down yesterday, and tried unrolling the lino over it, and it went popopopopopop as it shattered out of the (broadhead) tacks I had put it down with, and pulled a few out, tightly freaking wound that roll. I guess I should have had a heat gun on it, but decided it's a bit beyond that really. If it's gonna be all that shattery and brittle at "normal" temperature, then I guess it'll be cracked up and nasty within weeks, even if I could baby it into place now. So guess that old lino is too old for anything really. For now I've got a floor protector/shelf liner thing on it for a smoother main surface, we'll see how that goes, might get a bit of formica or something.

Then I've got those stacking bins either end, they are a more commercial quality type than household, but I don't trust them too much, they tend to sag. That is what is handy at the moment though. Might be looking for flat pack closet organiser cube things on sale cheap and put those either end instead. On top we have half a closet bifold door for a shelf. Think I only want test gear and LCDs up there. Seeing where the mega power bar fits, might screw it on shelf edge, might be at the back... might need attention, think the switch was iffy.

Anyway, getting towards an actual useful wrangling corner down there... it's not true about the breeding pair of Balrogs by the way.

Was working on my Athlon XP 2600+ system when it just stopped turning on. No sad little beep, no momentary fan spin-up, nothing. So I starting pulling things out until there was nothing left to pull out or unplug and it still wouldn't turn on. I pulled the motherboard out of the case, different power supply and power button and still nothing. The ASUS A7V8X-MX SE motherboard has a big green LED to show that it's getting stby power so that's helpful. I pulled out my multimeter started checking for shorts and didn't immediately find anything.

I was looking into ways to metaphorically jam a screwdriver into the ATX connector and jump start the thing, but instead walked away for 10 mins, came back and it turned right on. 🙃

The motherboard had a visibly bulging/leaking cap below the bottom PCI slot that I replaced when I first got it. The others looked ok so I left them. Is this a mobo where I should probably just do a full recap?

I´m getting ready to fix five resistors in a PS/2 model 50 motherboard, destroyed by its neofit previous owner. also the damaged veins.
I rescued the machine literally form the garbage and mud. Had to disassembly the keyboard down to the springs, for cleaning.
I couldn't recover the bottom and the back, so I will have to build some replacements.

and last week I repaired three videocards from my rescued-from-the-recycler collection , a SiS 63something, a Trident 3dimage and a Radeon 7000

Reinstalled MS-DOS 5 on my 386SX build.

Planning to do a dual boot with SCO Unix SystemV/386.

GigAHerZ wrote on 2024-02-17, 18:12:

dominusprog wrote on 2024-02-17, 17:29:

GigAHerZ wrote on 2024-02-17, 10:27:

It's an overkill that actually works worse. Fans (or any DC motor), just like LEDs, would prefer full 12V (LEDs with their appro […]
Show full quote

It's an overkill that actually works worse.
Fans (or any DC motor), just like LEDs, would prefer full 12V (LEDs with their appropriate full voltage) and the speed being controlled by turning it on and off very fast. So it's a PWM on powerline.
In practice, it means you can achieve way lower speeds while not stalling the fan. Also you have better starting probability. (With lower voltage, the fan might easily continue to run, but may not be able to start)

In aliexpress, you can find similar simple boards that would be more suitable for this scenario. ("12V PWM" would be a keyword. Without spending time on searching, already saw some for 1€ a piece, incl. shipping.)

Find what exactly? About the fan that isn't able to start, I understand what you said but I decreased the voltage to 7V which is high enough to start the fan.

A different little piece of electronics that is more suitable for controlling the fans than lowering the voltage.
If you just want to lower voltage, you could just use a resistor. No need to use that fancy buck-converter. 😀

Since using the resistor will limit the current, is not a good idea to use one.

Working on a 486 build 😀

I did some tooting with DOStodon and listened to some tracker track, both from my 5x86 160 (w/ Gravis Ultrasound).

( Alt YT link on the CubicPlayer fun: https://youtube.com/shorts/1RtYL5r1uYM?si=gkA56mFkluOWEafT )

bp

dominusprog wrote on 2024-02-18, 14:54:

Working on a 486 build 😀

IMG_20240218_174915.jpg

Nice! Love the colourful zipties and the PC speaker situation. 👍

And cable management without getting weird about it. 🤓

ubiq wrote on 2024-02-18, 17:00:

dominusprog wrote on 2024-02-18, 14:54:

Working on a 486 build 😀

IMG_20240218_174915.jpg

Nice! Love the colourful zipties and the PC speaker situation. 👍

And cable management without getting weird about it. 🤓

Thanks 🤓

I had flat space, the temptation was too great, made a beeline for a small stack of boxes which I had not been able to get into for years....

It's weird, I was standing there going, "What? What? What?" David Tennant as the Doctor style as I pulled out some stuff I didn't recognise, mingled with one or two things I've been looking for.

You'll spot in the pics, a Voodoo 3 2000, don't think it's the one I bought new, which I ran hard and it browned the board around regs etc, think I tried this one and it only did the first notch above stock speed. It's great to find it, but also a little dissappointing as I thought I had a "voodoo cache" of several boards together, and I now think they are a bit scattered, and not sure I'll find an 8MB V2 with them like I thought. Then in the same pic as that is a GF4 4600, which needs RAM reflowed or replaced and probably a few caps. Was driving me crazy how I couldn't find my "crappy" basic PCI gfx, well there they all are. The Virge looks like one of the Virgeiest ones that might be interesting to mess with in a socket 5 or so. Then also I knew I wasn't crazy... well, not all that crazy... well a specific kind of crazy... and did have a matrox mistake, there it is in the other pic, along with some randoms, a "real" network card, though DEC would argue since they did all the ethernet heavy lifting. That VGA wonder looks a bit sad though, that might have been a scrap bin rescue from somewhere, and the EGA seems to be a little tweaked. I have a better condition one of both I think. I dyslexified the GL5446 and thought I had a 5464 laguna for a couple of mins. Gotta get one of those more basic ones into my poor old socket 4 box, it doesn't deserve a 5430... well nothing does really.

Now motherboards a plenty also turned up, my main stash of T2P4s and some trashy looking socket 7s, but what I'm showing pics of were what surprised me most. A DEC LPXish board, huh, don't know where that came from. Then I hope the varta hasn't eaten too much of that neat single VB slot board, you see that AMD 386 DX40 on there? That might be fun to play with with VLB gfx and ample cache... also will have a 387 it can borrow. Then wow, didn't realise I had that PCI 486 board or a 386 motherboard wanting a CPU, I passed over a 386 a few months back, thinking I didn't have a hole for one. I maybe vaguely remember looking into this board years back and it's apparent absence of cache maybe didn't encourage me to bother much with it.

edit: now I'm confused, that's a V3 3000 isn't it? Only thought I have PCI 2000s and an AGP 3000, weird.

I recently got some great help here while fixing an old Vectra PC.

HP Vectra VL 6/450 - How to Power it up ?

The problem was that I was left with 19 surplus power switches. Now I used one more on a much more modern system. This is a Dell XPS one 27 AIO from around 11 years ago (almost retr0). I like this machine a lot, as it has a great display and still works very well, although the speakers and the CD drive are also already broken but I keep it alive. It had a very fragile power switch and this was the next thing to break.Replacements are expensive (and may fail soon as well) but with my stock of switches I saved the day!

It sure looks a bit homebrew, but it works !

Aui wrote on 2024-02-19, 06:56:

I recently got some great help here while fixing an old Vectra PC. […]
Show full quote

I recently got some great help here while fixing an old Vectra PC.

HP Vectra VL 6/450 - How to Power it up ?

The problem was that I was left with 19 surplus power switches. Now I used one more on a much more modern system. This is a Dell XPS one 27 AIO from around 11 years ago (almost retr0). I like this machine a lot, as it has a great display and still works very well, although the speakers and the CD drive are also already broken but I keep it alive. It had a very fragile power switch and this was the next thing to break.Replacements are expensive (and may fail soon as well) but with my stock of switches I saved the day! 20240216_153607.jpg
It sure looks a bit homebrew, but it works !

Reminds me of the 19" Dell LCD I was given many years ago (I'd already had it for years when COVID hit) with a broken power button which has been serving as the rightmost of the spread of three monitors on my daily driver PC ever since.

My solution there was to fill the hole for the button with hot glue to make a frosted window for the LED, drill a hole in the plastic over the actual location of the pushbutton, cut the top off a clear pushpin, and then wrap some trimmed electrical tape around it to keep it from falling out:

yeah, unfortunately I could not save the LEDs with my rudimentary fix. There were even different colors in that original button.

Now Im just thinking that there may be a future generation of Vogons and in 20 years they will have to fix these kind of highly integrated machines. I bet there will be plenty working 386 still around when the last 2010 All in One stops working forever...

ssokolow wrote on 2024-02-19, 07:19:

Reminds me of the 19" Dell LCD I was given many years ago (I'd already had it for years when COVID hit) with a broken power button which has been serving as the rightmost of the spread of three monitors on my daily driver PC ever since.

My solution there was to fill the hole for the button with hot glue to make a frosted window for the LED, drill a hole in the plastic over the actual location of the pushbutton, cut the top off a clear pushpin, and then wrap some trimmed electrical tape around it to keep it from falling out:

IMG_0733_adjusted.JPG

nice! there's a lot to be said for hot glue and fillers for such fixes- keeps things functioning but without having to buy or product exact replacements

Aui wrote on 2024-02-19, 08:33:

I bet there will be plenty working 386 still around when the last 2010 All in One stops working forever...

Yeah, it's gonna be in the chips themselves that problems occur I think. Inside a 386 you're hoping a few million doping atoms in the silicon don't wander too far away from the junction to work, in more recent stuff, it might only be a couple of hundred dopant atoms per transistor, with a hundred or thousand times more transistors for something to go wrong with, so statistical probability of being screwed over by diffusion is very much higher in more modern stuff.

BitWrangler wrote on 2024-02-19, 05:34:

I had flat space, the temptation was too great, made a beeline for a small stack of boxes which I had not been able to get into […]
Show full quote

I had flat space, the temptation was too great, made a beeline for a small stack of boxes which I had not been able to get into for years....

It's weird, I was standing there going, "What? What? What?" David Tennant as the Doctor style as I pulled out some stuff I didn't recognise, mingled with one or two things I've been looking for.

You'll spot in the pics, a Voodoo 3 2000, don't think it's the one I bought new, which I ran hard and it browned the board around regs etc, think I tried this one and it only did the first notch above stock speed. It's great to find it, but also a little dissappointing as I thought I had a "voodoo cache" of several boards together, and I now think they are a bit scattered, and not sure I'll find an 8MB V2 with them like I thought. Then in the same pic as that is a GF4 4600, which needs RAM reflowed or replaced and probably a few caps. Was driving me crazy how I couldn't find my "crappy" basic PCI gfx, well there they all are. The Virge looks like one of the Virgeiest ones that might be interesting to mess with in a socket 5 or so. Then also I knew I wasn't crazy... well, not all that crazy... well a specific kind of crazy... and did have a matrox mistake, there it is in the other pic, along with some randoms, a "real" network card, though DEC would argue since they did all the ethernet heavy lifting. That VGA wonder looks a bit sad though, that might have been a scrap bin rescue from somewhere, and the EGA seems to be a little tweaked. I have a better condition one of both I think. I dyslexified the GL5446 and thought I had a 5464 laguna for a couple of mins. Gotta get one of those more basic ones into my poor old socket 4 box, it doesn't deserve a 5430... well nothing does really.

Now motherboards a plenty also turned up, my main stash of T2P4s and some trashy looking socket 7s, but what I'm showing pics of were what surprised me most. A DEC LPXish board, huh, don't know where that came from. Then I hope the varta hasn't eaten too much of that neat single VB slot board, you see that AMD 386 DX40 on there? That might be fun to play with with VLB gfx and ample cache... also will have a 387 it can borrow. Then wow, didn't realise I had that PCI 486 board or a 386 motherboard wanting a CPU, I passed over a 386 a few months back, thinking I didn't have a hole for one. I maybe vaguely remember looking into this board years back and it's apparent absence of cache maybe didn't encourage me to bother much with it.

So that 386 board there seems to be the ECS 386L with the VLSI Topcat chipset. Wondering what the options are to fill the PGA132. Not sure also if it's missing the main oscillator, get spare and blank crystal spots all over the place on old boards, (Cost was high to get a board made back then so they covered a lot of options). Obvious CPU is an OG 386 in Intel or AMD flavor, but wondering about the cheap DLCs that are around, and whether they work in a basic fashion without having L1 support, which can be added, but not knowing whether the board works and having no testers I don't want to make the sitch too complicated.

Also you might have noticed that the PCI/486 board I called a matsonic, because on the back it has a matsonic sticker, not sure now if it belongs there, is actually a gigabyte model. Having some faint recollections about that DEC board, maybe I couldn't get more than 12MB working on it, which frustrated late 20thC use as a basic office/surfer.

Edit: took another look at the 386L board, the backside of the oscillator footprint had holes and solder peaked around them, so it was removed, it should have a crystal osc in that position. That's a note to self and for posterity in case anyone else finds one with a missing one that had it's holes cleaned up so good you couldn't tell.

I tried fiddling with the chipset registers on my HP Pavilion ze1210 craptop to see if I could get better performance. Enabling memory interleaving didn't affect performance significantly (I'm surprised that I could actually measure a 3% gain in the Sandra memory benchmark). I guess integrated video steals so much RAM bandwidth from the CPU that nothing helps, but video performance didn't improve either.

dominusprog wrote on 2024-02-18, 14:51:

GigAHerZ wrote on 2024-02-17, 18:12:

A different little piece of electronics that is more suitable for controlling the fans than lowering the voltage.
If you just want to lower voltage, you could just use a resistor. No need to use that fancy buck-converter. 😀

Since using the resistor will limit the current, is not a good idea to use one.

The modern Noctua low-noise adapters are just a resistor. There are lots of different ways to control fan speed, and they all have the problem of the fan not starting if you try to slow it down too much. The PWM controllers will usually run the fan at full speed for a brief period on startup to make sure it spins up reliably.