Thermalwrong wrote on 2023-11-29, 03:08:

Heh I give up for now, this took so dang long. I lost so many of the smaller capacitors & resistors somehow and it took ages to […]
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Heh I give up for now, this took so dang long. I lost so many of the smaller capacitors & resistors somehow and it took ages to find them, bend the legs, trim the legs. Check the values etc.

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Here's how it fits in the slot of one of my mini SBC computers. I wanted to just use it in the big testing PC since that's got the remnants of a real case to check fitment, but for this initial testing I needed -5v and to be able to see power consumption

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Good news and bad news...... the ISA connector works though and it's not falling off. The glue is more of a space filler, those metal legs inside the fibreglass are giving all the important mechanical strength it needs, more now with the traces soldered on too.

A blast(er) from the past!

While avoiding some other projects I took another look at my Creative SoundBlaster CT1350 that came from a scrapper where they'd cut the ISA connector off to get the precious gold. Well over time I depopulated the card, derived a complete PCB design and schematic for it (still not got that fabbed yet), then put a replacement ISA connector onto this original 90s PCB and repopulated it.

I could not figure out why the card's Adlib / OPL2 side would work but the SoundBlaster DSP would not detect at all. Last time I was thinking about scoping / logic analysing the address or data lines, or swapping out the main CT1336 bus logic chip but those are all hard options so I've ignored this card for well over a year now...

Today I decided to start verifying the connections of the IRQ pins, the Address pins - I can use the boardview I created to confirm the start and end of any trace:

Starting with the IRQs I found that IRQ 3's trace was broken where the jumper connects to the PCB trace, must've broken when I removed the jumper and since it's underneath the jumper plastic I can't spot it at all.
The Address pins don't go to many places except the CT1336 and all the address traces were fine... So this time I next looked at the Jumpers to set the Address to "22x" or "24x" and this trace that connects the other end of that jumper is broken!

Because it couldn't listen on either 220 or 240, the soundblaster DSP audio and all communication with the soundblaster's DSP was broken.

It seems that when I pulled the jumper when depopulating the card the hole & trace got damaged, which was then hidden by the jumper plastic on top of it. Soldering a wire on top works well:

No way anyone could've spotted this from looking at pictures unfortunately.

And here it is working playing Doom just as a sound test on the motherboard that I fixed, with the CPU that I fixed 😁

Now I'm in better spirits about the CT1350 - that means the CT1336 is resilient since I thought that had failed. With this boardview I can make reproduction PCBs like the Snark Barker, if I finish up the solder mask, I may even upload the full kicad project for it at some point since it seems to be correct 😀
See this thread for more on the SoundBlaster CT1350 boardview: Taking a repair to the extreme - Remaking Soundblaster 2.0 CT1350B PCB

That was some repair effort you did to that card 🤣

Tiido wrote on 2025-02-06, 03:10:

That was some repair effort you did to that card 🤣

Cumulatively, yeah. But today it was maybe 30 minutes of troubleshooting... how did I miss this the last time I was looking at the card? Also looks like *I* didn't damage those vias, the jumper pins had all been removed on this scrapped card since the scrapper saw gold and took those too, from looking at the archived auction pictures.

CT1350s are pretty rare though and I've wanted a proper CT1350 again for a long time, this broken one is what I ended up with so it's cool it's working again. I mean I've got at least one clone card but CT1350 is what I had long ago.

Anyways, so glad it's done! Now I've got the card working and OPL2 sounds great on it - it does seem to be a bus noise listener card though 😁

Checked what's wrong with my Voodoo2 I just bought.

Many pins are disconnected, but aligned, on a 500-0010, and one pin needs to be bent back but soldered.
There is some oxidation but overall looks nice.

With my other V2 (green one).

I guess Bits und Bolts was right about "always check the corners". 😀

Finally restored Windows ME on my Toshiba Satellite S2800-100.

I know the 2805 would be more desirable however I think the 2800 is good too.

I installed a SCSI card in the PackardBell P60 I got today and checked if this would yield some performance gains compared to the IDE controller - it did but it was a "µ-improvement".
In DOS, DOOMII / demo3, the SCSI's fastest time to the IDE's slowest time was 4522 to 4525 realtics - so less than 1/10 of a percent.

Continuing with my theme of getting bolder and replacing the Factory TIM on my Slot A CPU's. I decided to really up the level and replace the gunk on my T-Bird 900Mhz.

Its getting easier and easier and I feel more comfortable each time. Its very obvious on the test after completing the new paste, how much better it is than before. The aluminum plate gets hot fast.

I was in for a treat this time as my 900Mhz - TBird has a 1Ghz core!!. Pretty sweet. If I can't get ahold of a Golden fingers device over the next couple months. I am going to move some resistors around on the board and turn it into a 1000Mhz T-Bird permanently. Its already running at 1.75V per the current resistor layout, which is more than enough to run 1Ghz stock.

Fun times! 😊

Good for you man, after that you only have to get a dead 1GHz Tbird and swap the black cover. If you ever going to sell it, don't forget to mention it in the ad. :p

I'll never going to open mine, too afraid to damage it.

Having fun with a GA-6BXDU, 2x Katmais and a 9GB IBM DNES-309170 SCSI drive.

I have some more stuff on the backlog though - namely testing out a Tualatin SL5ZF, a Chaintech 6BJM0 I just recapped and an Acorp 5ALI61 (since I'm highly curious to find out about how good is the Aladdin V, rev E.)

I've been busy with this MiniScribe 8425XT drive. Replaced the two stepper motor IC's, but the motor won't do anything. Spindle is spinning, error code 8 and 9 from the LED. That makes sense since the stepper doesn't work. So I'm still thinking what is going on here... When I move the interrupter/shaft by hand its going quite easy.

Maybe the drivers are not receiving power ?

Tiido wrote on 2025-02-08, 13:57:

Maybe the drivers are not receiving power ?

If I remember correctly, the chips are getting warm a bit. I guess I could check the input or other pins with a scope? See if it's getting signals.

If you have a scope you check check all kinds of things. I assume original motor was seized and that perhaps ended up killing the drivers, or their current limit (fuse somewhere perhaps). It is definitely worth to check the power paths and any drive signals.

AGP4LIfe? wrote on 2025-02-08, 03:17:

I was in for a treat this time as my 900Mhz - TBird has a 1Ghz core!!. Pretty sweet. If I can't get ahold of a Golden fingers device over the next couple months. I am going to move some resistors around on the board and turn it into a 1000Mhz T-Bird permanently. Its already running at 1.75V per the current resistor layout, which is more than enough to run 1Ghz stock.

Fun times! 😊

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I love that the aluminium plate on a tbird still has the dents, that were supposed to make contact with the external cache chips on the older core 😎

Edit: why does the wrong attachment show up in the quote, when I use PXL_20250207_222322827.jpg in the quote?

Been re-capping some old parts recently, using mostly my YIHUA 948, and it works great. However, I have multiple options.

The other day I came across one of the best de-soldering tools I've ever used, but had completely forgotten about, and didn't know were still made.

Back in the 90's, I used to use one of those nasal bulbs people use on babies noses. I used it to either suck, or blast out, the solder from through-hole components and they worked amazingly well. The silicone ones held up really well to the heat for sucking.

Fast-forward to last week, and I ran across a few being sold on Amazon and those memories came flooding back. Well, I got one, one actually made for soldering work, and it's as amazing as I remember!

Now, back to re-capping! 😀

I've always found solder wick to be extremely underrated for clearing through holes. The problem often isn't the wick and less about technique as it is getting a high quality wick with embedded flux. There are actually a lot of counterfeits of name brand solder wicks too, which makes it very difficult to know what you're buying if it isn't from a reputable seller.

Tested the V2 I bought and it's working.
Mojo just doesn't see the 2nd TMU, the one I have to reflow as 2 rows of pins are detached.

Win98 does load it and it appears as V2 8MB.
Now I have to build a SLI bridge.

While I was upgrading my modern system and had the new power supply on the table, I decided to dig out that dead Anigma 586 motherboard I've mentioned in a few other threads and do some troubleshooting. Of course, it works now.

First, I tried to power it on with only a CPU and RAM installed, and I was surprised by POST beeps. Then I smelled something getting hot, which was the FET in the CPU VRM. It's a switching VRM (a 1970s-style design with a discrete transistor oscillator and a shunt regulator as a voltage reference, even though controller ICs existed in 1997), and considering that the board was designed without a heatsink, I think there's something wrong with the gate drive.

I added a video card and a fan for the VRM, and it displayed the fancy Gateway 2000 animated splash screen. I didn't connect any drives to see if it would boot because of the VRM heating problem. I think that's good enough until I decide to build a full system around it. At the same time, I found that CR2032 battery holders have the same lead spacing as the oddball BR2335 holder.

I even reverse-engineered the VRM for all of you to marvel at. The designators in this schematic don't match the PCB at all, D1 is the closest thing in the LTspice database (the actual diode is an MBR1035), I left out some of the output caps, and some of the cap values are a wild guess (I didn't desolder and measure them).

I didn't notice how dusty my monitors were.

Found father's old spare floppy for the Tandy TRS-80, still NOS:

Shugart SA400L with delivery note and test documentation:

Also made a wireless mouse 😉 :

That is a hate crime.
You should be banned for that abomination.