gerry wrote on 2024-02-19, 15:18:

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

I'd have tried to come up with a better solution if I'd expected it to last as long as it has. At the time, I chose a "thing I can never undo" (drilling a hole in the case) because I expected it to give me a few years and then be just another of countless 19" LCD monitors that either die and get thrown away or have their PSU boards recapped.

(See, for example, my Power Mac G4 as a contrast. I've had the "use an ordinary ATX PSU" cables for months, but I haven't had time to figure out how to research what PSU to buy so the only things which project from it will line up with the existing precise "power socket and 110/220 slider" cut-outs on the back of the case and avoid the need to cut up a G4 Quicksilver case... either that or see if there's a normal ATX PSU cut-out beneath that plastic moulding and, if so, if it's possible to safely and non-destructively remove the back plastic and box it up. That just occurred to me.)

I tend to take an approach that goes "mod things towards more standard" meaning, unless it's a complete Frankenstein from several different pieces of junk, to try for a clean mod of something that takes a weird part, to take a standard part, rather than going for modding to splice an almost right also weird part or something.

I found my old Covox :

I built it I think in 2005 but maybe 2004 or such, and because the computer I got had no ISA and no sound in DOS games and this was a way to get at least some sound. I could also make it do sound from my own programs too ~
Model number says it is the second iteration, but I have no memory of the first one...
I remember it was a bit of a struggle to find suitable resistors, 10k was easy but 20k not so much...

Tiido wrote on 2024-02-21, 05:05:

I found my old Covox : Covox0.jpg Covox1.jpg I built it I think in 2005 but maybe 2004 or such, and because the computer I got h […]
Show full quote

I found my old Covox :
Covox0.jpg
Covox1.jpg
I built it I think in 2005 but maybe 2004 or such, and because the computer I got had no ISA and no sound in DOS games and this was a way to get at least some sound. I could also make it do sound from my own programs too ~
Model number says it is the second iteration, but I have no memory of the first one...
I remember it was a bit of a struggle to find suitable resistors, 10k was easy but 20k not so much...

I actually have an attempted Covox which I thought was screwed up and was planning to ask for "what am I missing in these circuit diagrams other people had no trouble with?" EE help on that I've been meaning to re-test because it's possible the mistake was in replacing the hard-wired cable on the computer speakers.

(I don't think I only tested with one pair, but it's entirely possible and that pair later turned out to somehow have gotten miswired while I was replacing the bad cable, resulting in the left and right channels cancelling each other out when audio is mono/centered.)

Funny enough, I originally built the thing just because I thought it'd be a fun, nerdy EE project but, now that I've got an HP t5530 thin client, I think I'll test out Virtual SoundBlaster to see if it produces a DOS option faster than running DOSBox on Win98SE on an 800MHz VIA chip, more compatible than Windows 98's WDM SoundBlaster emulator, and less "crash the whole system hard when I test with Skunny Kart" than SBEMU.

That's.. OLD 😁

LCD panel transplant - the original looked like the LCD layer was delaminating so has these weird squiggles at the edges of the display:

I went into my parts bin of LCDs and found a similar lq121s1lh02 - 800x600 LCD that runs at 3.3v, the laptop gives 5v to the LCD. I tested the backlight and the backlight has bright spots and dark spots all over it, rubbish. The fresnel sheets look like they got scratched or are starting to go moldy - they are being stored essentially outside right now 🙁

Tried something I've never done before which was putting a different LCD panel in place of the original damaged LCD panel. The mini grinder tool made it possible and the backlight sheets made it through the transplant operation mostly undamaged.
I had to cut lots of plastic from the frame to make it fit but it's looking good and lights up the whole pixel area of the LCD just a little adjustment needed still. There's an AMS1117 converting 5v into 3.3v so the LCD panel electronics don't burn up, and the new panel's pinout is different from the original so some minor rewiring of the LVDS pairs was needed, but it works.
The repaired LCD looks great except for a bright line at the top but that doesn't notice too much in use, compared to the squiggles or bright spots. This means I've got one very nice LCD screen from 2 useless ones 😀

Me again 😀 New topic though because I fixed one of my video cards - it's been sitting around on my desk for a week or two. I couldn't figure out why this Medion Geforce 3 Ti200 could display 2D perfectly but would restart the system almost immediately when running any 3d stuff.
I was going to set up a secondary test system doubting the AGP power output on my MSI 865 P4 testing system - but that wasn't it. The card has been sitting on my desk for a while and I looked in its direction at a different angle today and spotted one of the capacitors sitting at a jaunty angle:

The purple polymer 4v 510uF capacitor had one leg broken off completely somehow. That I think was the filter capacitor for the voltage output of the GPU VCC rail, replaced it with this red poly-cap salvaged from another motherboard/card years ago and now the card is working 100%
edit: nope, it was the 3.3v input to the voltage regulator for GPU vcore. Which is why there's just one. The two poly caps next to it are the GPU vcore filter caps.

This is actually pretty interesting - there's an FX 5700LE card that did basically the same thing with crashing on 3d although 2d was perfect, perhaps it needs recapping.

Installed some cooling for my Voodoo 3 3000

Started soldering some AmigaMidi boards. The passives are done, I'll likely get them finished tonight.

I got outbid on an AMD Athlon XP 3200+ Barton 400MHz CPU.

There were a lot of people watching it and it was up to just under £20 for most of the last day, so my gut was telling me it was very likely to go for more than the roughly £40 the last one went for. So with about 20 seconds to go I put in a bid of £75 - which is a lot don't get me wrong, but less than buying one from mainland Europe at the moment - expecting it to end somewhere in the £50-60 region. It was on me for £45 until a second or two at the end, when I was outbid and it went for £77.

Absolutely astonishing. I guess someone else really wanted it as well!

So with my tail between my legs, I ordered an almost identital XP 3000+ - same core, same stepping - from Germany for about £34. I'll know that it's not the absolute top dog, but it's close enough for now. And I'm pretty sure the nForce2 board it's going in will happily let it run at 3200+ speed anyway.

Thermalwrong wrote on 2024-02-22, 02:47:

LCD panel transplant - the original looked like the LCD layer was delaminating so has these weird squiggles at the edges of the […]
Show full quote

LCD panel transplant - the original looked like the LCD layer was delaminating so has these weird squiggles at the edges of the display:
IMG_3010 (Custom).JPG

I went into my parts bin of LCDs and found a similar lq121s1lh02 - 800x600 LCD that runs at 3.3v, the laptop gives 5v to the LCD. I tested the backlight and the backlight has bright spots and dark spots all over it, rubbish. The fresnel sheets look like they got scratched or are starting to go moldy - they are being stored essentially outside right now 🙁

Tried something I've never done before which was putting a different LCD panel in place of the original damaged LCD panel. The mini grinder tool made it possible and the backlight sheets made it through the transplant operation mostly undamaged.
I had to cut lots of plastic from the frame to make it fit but it's looking good and lights up the whole pixel area of the LCD just a little adjustment needed still. There's an AMS1117 converting 5v into 3.3v so the LCD panel electronics don't burn up, and the new panel's pinout is different from the original so some minor rewiring of the LVDS pairs was needed, but it works.
The repaired LCD looks great except for a bright line at the top but that doesn't notice too much in use, compared to the squiggles or bright spots. This means I've got one very nice LCD screen from 2 useless ones 😀

that was something of a risk but it went well! a good way to use an officially 'incompatible' part

zuldan wrote on 2024-02-23, 07:36:

Installed some cooling for my Voodoo 3 3000

Cooling.JPG

I don't think that's enough cooling. You need at least one more fan. 😉

Well, that took a while, but my Atari ST emulators are done. And now that they're done and it feels good to have done it 😀

Shponglefan wrote on 2024-02-23, 17:49:

zuldan wrote on 2024-02-23, 07:36:

Installed some cooling for my Voodoo 3 3000

Cooling.JPG

I don't think that's enough cooling. You need at least one more fan. 😉

Maybe I need to underclock it to try improve the cooling 😉

Thermalwrong wrote on 2024-02-22, 02:47:

LCD panel transplant - the original looked like the LCD layer was delaminating so has these weird squiggles at the edges of the […]
Show full quote

LCD panel transplant - the original looked like the LCD layer was delaminating so has these weird squiggles at the edges of the display:
IMG_3010 (Custom).JPG

I went into my parts bin of LCDs and found a similar lq121s1lh02 - 800x600 LCD that runs at 3.3v, the laptop gives 5v to the LCD. I tested the backlight and the backlight has bright spots and dark spots all over it, rubbish. The fresnel sheets look like they got scratched or are starting to go moldy - they are being stored essentially outside right now 🙁

Tried something I've never done before which was putting a different LCD panel in place of the original damaged LCD panel. The mini grinder tool made it possible and the backlight sheets made it through the transplant operation mostly undamaged.
I had to cut lots of plastic from the frame to make it fit but it's looking good and lights up the whole pixel area of the LCD just a little adjustment needed still. There's an AMS1117 converting 5v into 3.3v so the LCD panel electronics don't burn up, and the new panel's pinout is different from the original so some minor rewiring of the LVDS pairs was needed, but it works.
The repaired LCD looks great except for a bright line at the top but that doesn't notice too much in use, compared to the squiggles or bright spots. This means I've got one very nice LCD screen from 2 useless ones 😀

I did an LCD transplant last year. The new LCD I put in had a refresh rate significantly better than the original, as well as better contrast. I did it for fun. I haven't used the panel since initial testing to make sure it works. I'm kind of curious if the faster refresh rate will be noticeable, or if the control board is too old to drive it fast. Something to test in the future, I guess

Treated my 486 setup with new Rubycon caps. Original ones looked beaten. However after running them trough my bench LCR comically old ones measured closer to 220uF then brand new Rubycons. Still new ones were well in 20% spec.
ESR @100khz was slightly higher for one old one at 0.23Ohm compared to rest with 0.15Ohm measurement. However I don't think it's critical.
I was slightly worried that old ones were rated only at 85C while one of them is located right next to voltage regulator with spec temp oner 100C. With my Am486 DX2-80 I measured regulator temp 75C.
Then again board is 30 years old and still working so 85C was good enough...

I also added brand new heatsink to CPU. Seems to be good enough. During multi hour stress test it never reached 50C. Farnell/Element14 is selling them with thermal adhesive pad attached. Quite convenient.

Also joined finally theretroweb.com community and made my first contribution by sharing better quality MB pic.

I was going to fix the missing caps on my 8 mb voodoo 2 I got years ago. Did not get it to work. Gets stuck on 3dfx logo. So I put an other voodoo 12 mb in there instead.

It did not work either... Had a look at it and yeah it also has a missing cap otherwise it looks fine. Sadly I don't have that cap at hand.

Ok then I try my other voodoo 2 12mb card. Also this did not work. It has a bent pin on one of the tmus. Its not shorted or so but it might be cause if the problem.

I am sure one of these two 12mb worked 2 years ago.

So now I'm a bit bummed out as I realize I don't have a single working voodoo card when I thought I had at least 1.

I need to cool my head a bit and try with an other computer that at least has a good way of transferring files and that is in a tower case.

What demos are good for testing voodoo 2s? What are the most stable drivers? All of the cards are Creative labs.

Upgrading my Dell Precision M4400 Laptop with parts from the recycling store;

Double memory 4GiB -> 8 GiB
Double number of Cores 2C -> 4C
Quadruple amount of cache 3MiB -> 12 MiB

Core2Duo Mobile P8700 -> Core2Extreme Mobile QX9300

Oh, and the donor had a Mobile Modem as well, which also came over 😀

i streamed NASCAR Racing 2 on retro PC under Rendition Verite video card 🤣 https://www.twitch.tv/whitemagicraventv

vutt wrote on 2024-02-24, 10:42:

Treated my 486 setup with new Rubycon caps. Original ones looked beaten. However after running them trough my bench LCR comicall […]
Show full quote

Treated my 486 setup with new Rubycon caps. Original ones looked beaten. However after running them trough my bench LCR comically old ones measured closer to 220uF then brand new Rubycons. Still new ones were well in 20% spec.
ESR @100khz was slightly higher for one old one at 0.23Ohm compared to rest with 0.15Ohm measurement. However I don't think it's critical.
I was slightly worried that old ones were rated only at 85C while one of them is located right next to voltage regulator with spec temp oner 100C. With my Am486 DX2-80 I measured regulator temp 75C.
Then again board is 30 years old and still working so 85C was good enough...

I also added brand new heatsink to CPU. Seems to be good enough. During multi hour stress test it never reached 50C. Farnell/Element14 is selling them with thermal adhesive pad attached. Quite convenient.

Also joined finally theretroweb.com community and made my first contribution by sharing better quality MB pic.
newcaps.jpg
qdi_v4s471.jpg

Cool 😀 What do you use for ESR testing? I've just got one of those little transistor testers and it's mostly guesswork except for caps that have visibly failed or are known to be the failure point already in the circuit. Surprising that those original caps have held up so well honestly, but maybe the caps on that board running a linear regulator are not driven as hard as they would be for a switching power supply.

Joakim wrote on 2024-02-24, 13:13:

I was going to fix the missing caps on my 8 mb voodoo 2 I got years ago. Did not get it to work. Gets stuck on 3dfx logo. So I […]
Show full quote

I was going to fix the missing caps on my 8 mb voodoo 2 I got years ago. Did not get it to work. Gets stuck on 3dfx logo. So I put an other voodoo 12 mb in there instead.

It did not work either... Had a look at it and yeah it also has a missing cap otherwise it looks fine. Sadly I don't have that cap at hand.

Ok then I try my other voodoo 2 12mb card. Also this did not work. It has a bent pin on one of the tmus. Its not shorted or so but it might be cause if the problem.

I am sure one of these two 12mb worked 2 years ago.

So now I'm a bit bummed out as I realize I don't have a single working voodoo card when I thought I had at least 1.

I need to cool my head a bit and try with an other computer that at least has a good way of transferring files and that is in a tower case.

What demos are good for testing voodoo 2s? What are the most stable drivers? All of the cards are Creative labs.

That's totally fixable and you can use some the mojo utility to find out which part is bad. Since all 3 are now bad you should probably look at how these are being stored - the QFP (quad flat pack) chips on the Voodoo 1/2/Rush cards have lots of pins with pretty weak solder and that's getting worse over time it seems. It's possible if the card is stored squished / twisted with other cards the solder on the legs could eventually come loose.
See this thread for some details on diagnostics for the Voodoo 1 - it's the same for the Voodoo 2 but many more moving parts / things to go wrong: 3Dfx Voodoo 1 - Low level hardware information and diagnostics thread
There's also some youtubers like Bits und Bolts, vswitchzero and Nitton Åttiofyra that I think all post on this forum and maybe could help.
I've got at least 1x Voodoo 2 card back to working (bought it as for spares / repairs) by finding the general area of the fault with mojo / basic diagnostics then using that to resolder just the area of the affected chip which got it running again.

smtkr wrote on 2024-02-24, 00:39:

Thermalwrong wrote on 2024-02-22, 02:47:

LCD panel transplant - the original looked like the LCD layer was delaminating so has these weird squiggles at the edges of the […]
Show full quote

LCD panel transplant - the original looked like the LCD layer was delaminating so has these weird squiggles at the edges of the display:
IMG_3010 (Custom).JPG

I went into my parts bin of LCDs and found a similar lq121s1lh02 - 800x600 LCD that runs at 3.3v, the laptop gives 5v to the LCD. I tested the backlight and the backlight has bright spots and dark spots all over it, rubbish. The fresnel sheets look like they got scratched or are starting to go moldy - they are being stored essentially outside right now 🙁

Tried something I've never done before which was putting a different LCD panel in place of the original damaged LCD panel. The mini grinder tool made it possible and the backlight sheets made it through the transplant operation mostly undamaged.
I had to cut lots of plastic from the frame to make it fit but it's looking good and lights up the whole pixel area of the LCD just a little adjustment needed still. There's an AMS1117 converting 5v into 3.3v so the LCD panel electronics don't burn up, and the new panel's pinout is different from the original so some minor rewiring of the LVDS pairs was needed, but it works.
The repaired LCD looks great except for a bright line at the top but that doesn't notice too much in use, compared to the squiggles or bright spots. This means I've got one very nice LCD screen from 2 useless ones 😀

I did an LCD transplant last year. The new LCD I put in had a refresh rate significantly better than the original, as well as better contrast. I did it for fun. I haven't used the panel since initial testing to make sure it works. I'm kind of curious if the faster refresh rate will be noticeable, or if the control board is too old to drive it fast. Something to test in the future, I guess

If that's from a TN panel to an IPS panel like on a Thinkpad or something, the difference should be quite immediately noticeable - I've been interested in LCD stuff for a long time so swapping a Thinkpad T440 to a good LCD panel for cheap was really worth it.

I did the final adjustments to the LCD panel fitting today and it looks great 😀 Two bad LCDs (one bad LCD panel, the other a bad backlight uniformity) make one just about perfect LCD. These were both basic 800x600 LVDS TN panels that by modern standards aren't great but back then were "Active Matrix TFT". Up to a few years back they were cheap and plentiful but now they're pretty rare so I've got to use up whatever parts I can: