Have some time off work this week, so resumed trying to clear my repair backlog starting with this Roland SCC-1.

Somewhere in this sound generation circuit something is broken. Just to need to find it...

Shponglefan wrote on 2023-12-27, 06:08:

Have some time off work this week, so resumed trying to clear my repair backlog starting with this Roland SCC-1.

Somewhere in this sound generation circuit something is broken. Just to need to find it...

You diagrammed that all out by hand? That's awesome. I increasingly find myself wishing the the EE exposure I'd had at uni had been more pragmatic and fewer k-maps and RLC calculus.

DeathRabbit679 wrote on 2023-12-27, 06:46:

Shponglefan wrote on 2023-12-27, 06:08:

Have some time off work this week, so resumed trying to clear my repair backlog starting with this Roland SCC-1.

Somewhere in this sound generation circuit something is broken. Just to need to find it...

You diagrammed that all out by hand? That's awesome. I increasingly find myself wishing the the EE exposure I'd had at uni had been more pragmatic and fewer k-maps and RLC calculus.

I'm afraid I can't take the credit for this diagram; it's a print out of the SCC-1 service manual.

I'm just using it to figure out what to test.

DeathRabbit679 wrote on 2023-12-27, 04:35:

Shponglefan wrote on 2023-12-27, 04:25:

DeathRabbit679 wrote on 2023-12-27, 04:19:

On visual inspection, a crystal oscillator looks to have been smacked and is at a 30 degree angle. Rest in peace, canopus, you beautiful 6mb voodoo :'(

If it is just the crystal that should be an easy fix.

For someone who isn't garbage at working with hardware, yeah. For me, attempting to fix it would probably turn it from a somewhat broken card into a completely destroyed card. I am dogshit at electrical debug and barely passable at soldering THT. I'll probably try to move it on down the line for free to someone in town who would stand a legit shot at fixing it then they can use it or sell it for 10000 bucks or whatever haha

Please say you live in Næstved, Denmark 🤣 I'd love to give that card a decent try 😀

H3nrik V! wrote on 2023-12-27, 11:43:

DeathRabbit679 wrote on 2023-12-27, 04:35:

Shponglefan wrote on 2023-12-27, 04:25:

If it is just the crystal that should be an easy fix.

For someone who isn't garbage at working with hardware, yeah. For me, attempting to fix it would probably turn it from a somewhat broken card into a completely destroyed card. I am dogshit at electrical debug and barely passable at soldering THT. I'll probably try to move it on down the line for free to someone in town who would stand a legit shot at fixing it then they can use it or sell it for 10000 bucks or whatever haha

Please say you live in Næstved, Denmark 🤣 I'd love to give that card a decent try 😀

I wish, those would be more interesting environs than the Southeastern United States.

Today I spent the better part of two hours trying to figure out why a nubus card in a macintosh was giving me a green screen on my dell CRT. The answer ended up being the CRT not liking anything but regular vga. Apparently it is that picky.

Weird, dell monitors have usually been quite flexible. There's a possibility it's just not supporting expected prehistoric VGA resolution IDs. Dammit, forgot the name of it, expects to see certain loads between certain pins for resolution capability.

edit: ah right, old type shown in DDC article https://en.wikipedia.org/wiki/Display_Data_Channel

I was testing my Voodoo1 8Mb that I listed on eBay 😀
Yep, thats also a Eizo s2133, a fantastic monitor.

Fired up some classics on the ole' portable Tuallie 1.2GHz.

Looking for an ISA SCSI controller with floppy, does anyone know the existence of such a card with a 68p connector instead of 50p?

Adaptec 1542CP is the go-to for SCSI on ISA. these models come with floppy support as well.

AFAIK there are no 68-pin or wide scsi controllers for ISA. - there are for E-ISA.

ISA cant handle the wide-scsi bandwidth anyway.

luckybob wrote on 2023-12-29, 17:48:

Adaptec 1542CP is the go-to for SCSI on ISA. these models come with floppy support as well.

AFAIK there are no 68-pin or wide scsi controllers for ISA. - there are for E-ISA.

ISA cant handle the wide-scsi bandwidth anyway.

Thanks bob, then I will go for that model, with the use of some converters/adaptors for my disks.
Edit: found a US seller at that one place, shipping was more than the card...

Today I've finished recapping the ECS K7S5A socket A motherboard. It had G-Luxon branded caps and almost all of them in the CPU VRM area were bulging. I've used Rubycons and Jamicons for replacement.

I had to clean it as well, because it was in rough shape. Right now it seems that after recapping it's working fine. However I'll have to do some more thorough testing.

Today I went hunting in my parents' attic. I knew I had left some stuff there, but was not sure what to expect. I was not disappointed:

I am so happy to have recovered my 3dfx Voodoo 1 ! I thought it was lost or I had given it to a friend back then. This (re)discovery made my day.

Got some security monitors...
"Should work" turned into ... does not work at all...

These monitors have integrated power supplies in the stand, so i tried another one and ... didnt work too.
I opened the monitor and was greeted with 13 caps that were bulging... even it is a 12V device...

I replaced all caps with some cheap looking ones i got years ago and never used.
I didnt want to get fresh ones for a device i dont even know is working...
They are 25v instead of 16v, they look like the cheapest caps you can produce and they are too large... BUT... it works now.

The power supply in the stand was broken too... all caps exploded, so i replaced the whole power supply with an external one i managed to get inside the stand and use the original connectors.

It looks like original and works. Great... I think i will have to repair all 5 Monitors i got from this type...

Been having an absolutely wonderful evening testing out the AA370TS slotket, on a proper mainboard - ABIT's BE6-II.

Specs:

Channel Well ISO-500PP PSU
ABIT BE6-II ver 1.1 (according to CPU-Z)
AA370TS slotket + Coppermine 1GHZ SL5DV 133FSB
Geforce 4 Ti 4200 128MB
512MB PC133
SB Live CT4830
RTL8139D NIC
40GB WD Caviar
NEC DVDRW
XP SP3 Pro

Moves great despite being SP3. As long as you don't try browsing the internet.

Between yesterday and today, I've been doing some troubleshooting, on a 486 4Flud-1.0 motherboard, I'm still not getting any progress, but I have some repairs to do, currently the post card doesn't show any code (— —), for tomorrow I should fix some corroded tracks, and clean the contacts of the KB-BIOS chip, all the work done so far can be found here:
Re: Test and troubleshoot PC@LIVE motherboards
If you have any suggestions, or think it is necessary to check something else, I'll be waiting, and in the meantime, thank you and Happy New Year.

Resumed working on a silly six sound card 486 build.

Debating whether to go with the 486 DX4-100 overdrive or Pentium 83 overdrive. Probably going to stick with the 486 though...

I love how the mainboard is just as long as that Sound Blaster (or so I assume it is, a SIMM-upgradeable SoundBlaster) in the last slot, just next to the Overdrive.

PC@LIVE wrote on 2023-12-31, 21:40:

If you have any suggestions, or think it is necessary to check something else, I'll be waiting, and in the meantime, thank you and Happy New Year.

Happy New Year as well!

Reading through your log, you sound like you're on the right track.

Only other thing to check might be the BIOS chip itself to make sure it's got a proper ROM. Although you could always do that if it still doesn't work once the traces and other corroded bits are fixed.