VOGONS


Reply 13301 of 27441, by Tiido

User metadata
Rank l33t
Rank
l33t
SSTV2 wrote:

440LX won't work with non 1/2 FSB PCI bus dividers, intel chipsets doesn't support asynchronous PCI bus mode, unfortunately. If AGP card checks out, then most likely some device on the PCI bus causes system instability as 41.7MHz freq. is way over the specs for it.

Then that source of instability is the southbridge, since that's the only other PCI device left during my testing. All other cards besides video that I plan to use in the machine work fine at 50MHz PCI even. I have ruled out power supply issues, there's no meaningful ripple at any rail present in the system and everything is within tolerances.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 13303 of 27441, by Deksor

User metadata
Rank l33t
Rank
l33t

Page 666 😈

Anyways, @Predator99 I'm currently trying to do the same with two Seagate ST277R and a Tando TD 362, but so far no luck (and the bearings of the head mechanism are starting to fail on the tandon, so the head don't move as far as it should go on the disk ...)

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 13304 of 27441, by Turbo ->

User metadata
Rank Member
Rank
Member

Repaired traces, replaced crystal oscillator and two transistors on an 286 motherboard, that refuses to count BIOS time.

Attachments

  • IMG_8623.JPG
    Filename
    IMG_8623.JPG
    File size
    594.32 KiB
    Views
    915 views
    File license
    Fair use/fair dealing exception

Reply 13305 of 27441, by HanJammer

User metadata
Rank Oldbie
Rank
Oldbie

Finally cleaned up this Turbo XT machine I bought recently (after cleaning this machine is almost immaculate - certainly less dirty than my modern PC 🤣)... browsed through the HDD (it seems between 90 and 94 it belonged to some PhD lady from Warsaw University of Technology - a lot of scientific stuff and her projects) and paired it with recently purchased monitor...

Attachments

New items (October/November 2022) -> My Items for Sale
I8v8PGb.jpg

Reply 13306 of 27441, by HanJammer

User metadata
Rank Oldbie
Rank
Oldbie
Turbo -> wrote:

Repaired traces, replaced crystal oscillator and two transistors on an 286 motherboard, that refuses to count BIOS time.

Oh! I have very similar motherboard an simiral problems, but in my case - it counts time too quickly (like skips 2-3 seconds instead of 1)... Similar dammage too... I replaced ceramic caps which were cracked, but it didn't helped... which oscillator you replaced?

Attachments

  • M34_8.jpg
    Filename
    M34_8.jpg
    File size
    705.62 KiB
    Views
    910 views
    File license
    Fair use/fair dealing exception
  • M34_2.jpg
    Filename
    M34_2.jpg
    File size
    1.23 MiB
    Views
    910 views
    File license
    Fair use/fair dealing exception

New items (October/November 2022) -> My Items for Sale
I8v8PGb.jpg

Reply 13308 of 27441, by Turbo ->

User metadata
Rank Member
Rank
Member
HanJammer wrote:

Oh! I have very similar motherboard an simiral problems, but in my case - it counts time too quickly (like skips 2-3 seconds instead of 1)... Similar dammage too... I replaced ceramic caps which were cracked, but it didn't helped... which oscillator you replaced?

14.31818MHZ - usually 286 motherboards had oscillators with such frequency.

Reply 13309 of 27441, by FAMICOMASTER

User metadata
Rank Member
Rank
Member

Set up my trusty EGA Wonder card to test out my color monitor some more. Unfortunately, it doesn't seem to work with EGA resolutions (400 lines), but it works BEAUTIFULLY as a normal CGA monitor. The EGA board can display 16 glorious colors simultaneously on it. I think the EGA Wonder is even doing some hardware magic to get more colors out of it - At least that's what the manual seems to imply. It will even run some EGA software without losing sync!

Either way, it produces an excellent, bright picture with great contrast.
MVIMG_20191026_202105.jpg
MVIMG_20191026_203901.jpg

Now I need to get the buttons on the front of this monitor working. Anybody know how to work on these things? The 4 touch sensitive buttons on the front don't seem to work at all. This monitor definitely needs a good cleaning and retrobrite too, the yellow is really ugly.
MVIMG_20191026_203907.jpg

I'm also wondering... Is it possible to modify any of these monitors to take an EGA signal natively? I'm sure there's a mod out there somewhere that can change the frequency to a wider range.
If it is possible, I might mod this one while I'm restoring it, and pick up the other one I know is for sale to use in it's original configuration.

Reply 13310 of 27441, by Horun

User metadata
Rank l33t++
Rank
l33t++
Turbo -> wrote:
HanJammer wrote:

Oh! I have very similar motherboard an simiral problems, but in my case - it counts time too quickly (like skips 2-3 seconds instead of 1)... Similar dammage too... I replaced ceramic caps which were cracked, but it didn't helped... which oscillator you replaced?

14.31818MHZ - usually 286 motherboards had oscillators with such frequency.

Agree, the smaller oval shaped xtals back then were the 14.31mhz ones. And your Turbo XT looks great !

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 13311 of 27441, by Caluser2000

User metadata
Rank l33t
Rank
l33t
FAMICOMASTER wrote:

Now I need to get the buttons on the front of this monitor working. Anybody know how to work on these things? The 4 touch sensitive buttons on the front don't seem to work at all.

Maybe some thing disconnected or gunge preventing contact. Odd they are all not working though.

There's a glitch in the matrix.
A founding member of the 286 appreciation society.
Apparently 32-bit is dead and nobody likes P4s.
Of course, as always, I'm open to correction...😉

Reply 13312 of 27441, by FAMICOMASTER

User metadata
Rank Member
Rank
Member
Caluser2000 wrote:
FAMICOMASTER wrote:

Now I need to get the buttons on the front of this monitor working. Anybody know how to work on these things? The 4 touch sensitive buttons on the front don't seem to work at all.

Maybe some thing disconnected or gunge preventing contact. Odd they are all not working though.

I know they're not disconnected, because if the monitor is on and warmed up, switching the computer on will put it into a random mode and the "Mode" button will work 2-3 times and then it will quit. No other buttons will work, though. I've cleaned them numerous times with different chemicals but nothing changes this operation.

Also, the monitor can sometimes just switch modes at random and flicker between colors.

Reply 13313 of 27441, by MMaximus

User metadata
Rank Oldbie
Rank
Oldbie
FAMICOMASTER wrote:

Set up my trusty EGA Wonder card to test out my color monitor some more. Unfortunately, it doesn't seem to work with EGA resolutions (400 lines), but it works BEAUTIFULLY as a normal CGA monitor.

Nice monitor! Have you used the EGA wonder driver disk to switch modes on the card? The EGA Wonder 800+ can display EGA hi-res modes on a normal CGA monitor, thanks to interlacing. I would assume the standard EGA wonder can do the same thing...

Hard Disk Sounds

Reply 13314 of 27441, by wiretap

User metadata
Rank Oldbie
Rank
Oldbie
FAMICOMASTER wrote:
Caluser2000 wrote:
FAMICOMASTER wrote:

Now I need to get the buttons on the front of this monitor working. Anybody know how to work on these things? The 4 touch sensitive buttons on the front don't seem to work at all.

Maybe some thing disconnected or gunge preventing contact. Odd they are all not working though.

I know they're not disconnected, because if the monitor is on and warmed up, switching the computer on will put it into a random mode and the "Mode" button will work 2-3 times and then it will quit. No other buttons will work, though. I've cleaned them numerous times with different chemicals but nothing changes this operation.

Also, the monitor can sometimes just switch modes at random and flicker between colors.

Take out the button controller and replace all the components on it, especially any electrolytic capacitors. (even if they look fine) There is a ground reference that is becoming elevated -- this is why it seems to work initially, then quit, and why it can change at random.

My Github
Circuit Board Repair Manuals

Reply 13315 of 27441, by derSammler

User metadata
Rank l33t
Rank
l33t

Nothing that special, but since I have many loose HuCards for the PC Engine, I quickly made a 3d-printed sleeve to hold 7 HuCards in place. Turned out quite well. 😀 (ps: why 7? because the number of HuCards I own is a multiple of 7)

Reply 13316 of 27441, by yawetaG

User metadata
Rank Oldbie
Rank
Oldbie
wiretap wrote:
FAMICOMASTER wrote:
Caluser2000 wrote:

Maybe some thing disconnected or gunge preventing contact. Odd they are all not working though.

I know they're not disconnected, because if the monitor is on and warmed up, switching the computer on will put it into a random mode and the "Mode" button will work 2-3 times and then it will quit. No other buttons will work, though. I've cleaned them numerous times with different chemicals but nothing changes this operation.

Also, the monitor can sometimes just switch modes at random and flicker between colors.

Take out the button controller and replace all the components on it, especially any electrolytic capacitors. (even if they look fine) There is a ground reference that is becoming elevated -- this is why it seems to work initially, then quit, and why it can change at random.

Before doing that, replace the buttons themselves ( the switch part, not the button caps). They can wear out, and not switching on anymore is the usual symptom.

Reply 13317 of 27441, by yawetaG

User metadata
Rank Oldbie
Rank
Oldbie

As for recent activity, opened up my Zoom RT-323 drum machine because the slider was a bit glitchy, blew the dust out, and took some pictures of the internals (it has a battery soldered to the motherboard). Turns out the thing uses the Zoom ZSG-2 DSP/wavetable synthesizer chip, which is also found in many Taito arcade machines 😲 . Well, at least that explains why a drum machine with very little sound editing capabilities has sine, saw, and square wave patches, and also some patches that clearly use two different components that normally should be beyond standard drum machine fare...

Reply 13318 of 27441, by HanJammer

User metadata
Rank Oldbie
Rank
Oldbie
Turbo -> wrote:
HanJammer wrote:

Oh! I have very similar motherboard an simiral problems, but in my case - it counts time too quickly (like skips 2-3 seconds instead of 1)... Similar dammage too... I replaced ceramic caps which were cracked, but it didn't helped... which oscillator you replaced?

14.31818MHZ - usually 286 motherboards had oscillators with such frequency.

Yeah, but there are 3 oscillator on this board... OK, so the one which is heavly corroded in mine...

New items (October/November 2022) -> My Items for Sale
I8v8PGb.jpg

Reply 13319 of 27441, by FAMICOMASTER

User metadata
Rank Member
Rank
Member
yawetaG wrote:
wiretap wrote:

Take out the button controller and replace all the components on it, especially any electrolytic capacitors. (even if they look fine) There is a ground reference that is becoming elevated -- this is why it seems to work initially, then quit, and why it can change at random.

Before doing that, replace the buttons themselves ( the switch part, not the button caps). They can wear out, and not switching on anymore is the usual symptom.

There are no switches, they're touch sensitive. You don't push on them - You touch them. The black line is the separation between the contacts.

If I could get the damn thing open I'd be better able to check them.