VOGONS


First post, by SSTV2

User metadata
Rank Oldbie
Rank
Oldbie

I'm planning to replace a faulty DRAM chip on Voodoo2 card and at this moment I have two options - a visually similar looking 35ns (72MHz) EliteMT DRAM or a visually sticking out Mosel Vitelic 25ns (100MHz) chip. Ideally, I'd like V2 to look as original as possible and now I can't decide what should I do - experiment with a much slower, but more recently produced DRAM and expect it to operate well @ 90MHz+ or just stick with a known compatible Mosel Vitelic.

I could probably sand/soda blast Mosel Vitelic's white markings, so that it wouldn't visually stick out.

1.jpg
Filename
1.jpg
File size
1.4 MiB
Views
1212 views
File license
Fair use/fair dealing exception

So, what max frequency can be expected from a 72MHz DRAM that was produced almost two years later from original DRAMs?

Reply 1 of 14, by meljor

User metadata
Rank Oldbie
Rank
Oldbie

Can't answer your question, sorry, but I would go with the faster chip.

But how did you determine that that chip was the bad one? I have some defective cards laying around and would love to know..

asus tx97-e, 233mmx, voodoo1, s3 virge ,sb16
asus p5a, k6-3+ @ 550mhz, voodoo2 12mb sli, gf2 gts, awe32
asus p3b-f, p3-700, voodoo3 3500TV agp, awe64
asus tusl2-c, p3-S 1,4ghz, voodoo5 5500, live!
asus a7n8x DL, barton cpu, 6800ultra, Voodoo3 pci, audigy1

Reply 2 of 14, by SSTV2

User metadata
Rank Oldbie
Rank
Oldbie

It's a long story, but to sum it up, I had switched mem banks around for the TMU that was affected by the corrupted texturing. That helped me to pinpoint mem bank with a bad DRAM, from there I simply did a classic temperature related troubleshooting on each chip untill I found the faulty one.

If you have some dying Voodoo's, create a separate post for them with detailed description of the problem(s), I might be able to help.

Reply 6 of 14, by Thermalwrong

User metadata
Rank Oldbie
Rank
Oldbie

I put some similar ebay bought M11B416256A-25J chips on a Voodoo 2 8mb card to upgrade it to 12mb - the additional memory seems to work fine, though I haven't overclocked the card at all.

Reply 7 of 14, by SSTV2

User metadata
Rank Oldbie
Rank
Oldbie

After almost 1.5 month due, the DRAM ICs finally arrived. Every chip came from a different batch, because none of the date code on them match, but parts are legit and working.

1.jpg
Filename
1.jpg
File size
820.92 KiB
Views
989 views
File license
Fair use/fair dealing exception
2.png
Filename
2.png
File size
437.58 KiB
Views
989 views
File license
Fair use/fair dealing exception

Reply 8 of 14, by SSTV2

User metadata
Rank Oldbie
Rank
Oldbie

Replaced the crossed out DRAM IC, but texturing errors still remain. There is at least one more bad DRAM somewhere around the affected TMU 😵

Original picture:

bad dram.jpg
Filename
bad dram.jpg
File size
164.46 KiB
Views
942 views
File license
Fair use/fair dealing exception

DRAM IC is removed:

no dram.jpg
Filename
no dram.jpg
File size
108.03 KiB
Views
942 views
File license
Fair use/fair dealing exception

DRAM IC is replaced, ground textures are as it should be now:

dram replaced.jpg
Filename
dram replaced.jpg
File size
98.92 KiB
Views
942 views
File license
Fair use/fair dealing exception

After replacing DRAM, most of the textures in Quake are now displayed correctly.

almost.jpg
Filename
almost.jpg
File size
68.25 KiB
Views
942 views
File license
Fair use/fair dealing exception

Reply 9 of 14, by meljor

User metadata
Rank Oldbie
Rank
Oldbie

Nice job! What was the temp difference between a good and a bad chip?

asus tx97-e, 233mmx, voodoo1, s3 virge ,sb16
asus p5a, k6-3+ @ 550mhz, voodoo2 12mb sli, gf2 gts, awe32
asus p3b-f, p3-700, voodoo3 3500TV agp, awe64
asus tusl2-c, p3-S 1,4ghz, voodoo5 5500, live!
asus a7n8x DL, barton cpu, 6800ultra, Voodoo3 pci, audigy1

Reply 10 of 14, by SSTV2

User metadata
Rank Oldbie
Rank
Oldbie

There was no exceptional temp. difference among good and bad DRAMs, unfortunately. DRAMs closer to the FBI and TMU were always hotter.

Second bad DRAM was on bank0 (on TMU side) and it was semi good, which made it way harder to pinpoint, so after some testing and reasoning I've concluded that it must be somewhere on bank0. Because it didn't cause any texture flickering, like the crossed out DRAM (cooling remaining DRAMs, made no visual difference), I had to desolder DRAMs one by one and test them on a video card with DRAM sockets.

In conclusion, there were 2 bad DRAMs (U19 and U2) on both banks, I had relocated U1 to U2 so that freshly tinned DRAMs wouldn't stick out visually on the card too much.

1.jpg
Filename
1.jpg
File size
1.02 MiB
Views
907 views
File license
Fair use/fair dealing exception
2.jpg
Filename
2.jpg
File size
1.22 MiB
Views
907 views
File license
Fair use/fair dealing exception
3.jpg
Filename
3.jpg
File size
627.46 KiB
Views
907 views
File license
Fair use/fair dealing exception

Perfect quake texturing:

perfect quake.jpg
Filename
perfect quake.jpg
File size
84.45 KiB
Views
907 views
File license
Fair use/fair dealing exception

I had this Voodoo for almost 12 years, glad that I didn't try to fix it earlier, because I thought that texture corruption was caused by a faulty TMU back then.

Reply 11 of 14, by meljor

User metadata
Rank Oldbie
Rank
Oldbie

That's a shame, not willing to remove several chips just to find it out. I have several defective v2's , some I used some tiny parts from. Some don't work at all and some have artifacts.
I also have 11 working cards (7 boxed) so there is no real need to fix any.

But I have 2 sets of Creative 12mb cards in use and one of the cards has a tiny square in the upper left corner that is corrupted that I would like to fix. When using it in sli it is not noticeable and I guess it is a memory problem. Would have been nice to being able to pinpoint which chip it is.

Looks a bit like this: only in single card (did this with paint to give an example)

Attachments

  • perfect quake.jpg
    Filename
    perfect quake.jpg
    File size
    30.79 KiB
    Views
    878 views
    File license
    Fair use/fair dealing exception

asus tx97-e, 233mmx, voodoo1, s3 virge ,sb16
asus p5a, k6-3+ @ 550mhz, voodoo2 12mb sli, gf2 gts, awe32
asus p3b-f, p3-700, voodoo3 3500TV agp, awe64
asus tusl2-c, p3-S 1,4ghz, voodoo5 5500, live!
asus a7n8x DL, barton cpu, 6800ultra, Voodoo3 pci, audigy1

Reply 12 of 14, by xjas

User metadata
Rank l33t
Rank
l33t

Nice work! I've got an 8MB Creative card that does the same thing. Glad to know it's a fixable problem. Where'd you get the RAM chips?

CameraZOOM-20180903220509937.jpg
Filename
CameraZOOM-20180903220509937.jpg
File size
176.46 KiB
Views
871 views
File license
Fair use/fair dealing exception

twitch.tv/oldskooljay - playing the obscure, forgotten & weird - most Tuesdays & Thursdays @ 6:30 PM PDT. Bonus streams elsewhen!

Reply 13 of 14, by SSTV2

User metadata
Rank Oldbie
Rank
Oldbie
meljor wrote:

one of the cards has a tiny square in the upper left corner that is corrupted

It doesn't look like a typical, TMU memory related, texture corruption. What happens with the square when you set active only 1 TMU or disable texturing using environment variables? Post actual screenshots of the games.

xjas wrote:

Where'd you get the RAM chips?

China, via ebay. Though, before buying, I'd ask them to include ICs from the same batch only, that was an unpleasant surprise.

Reply 14 of 14, by meljor

User metadata
Rank Oldbie
Rank
Oldbie

Will test in a while and get back to it, the coming days I don't have the time to test. Would be interesting if we could find the problem! It seems like a tiny problem so the card should be reparable.
Thanx for the help...

asus tx97-e, 233mmx, voodoo1, s3 virge ,sb16
asus p5a, k6-3+ @ 550mhz, voodoo2 12mb sli, gf2 gts, awe32
asus p3b-f, p3-700, voodoo3 3500TV agp, awe64
asus tusl2-c, p3-S 1,4ghz, voodoo5 5500, live!
asus a7n8x DL, barton cpu, 6800ultra, Voodoo3 pci, audigy1