I've got this video card for my 486, but it will not display any colour except red. I've even replaced the VGA port to no effect. Is there any way I can fix this or did I waste a lot of money? Everything online says the only thing that can cause this is a broken VGA port, but that's not the case.
Can you take a pic of how port and it's surroundings look like ? (both top and bottom side)
Best case is damaged tracers or bad resistors/caps on the way to connector itself.
Worst case : Damaged ET4000 chip or RAMDAC.
agent_x007 wrote on 2022-11-01, 22:35:Can you take a pic of how port and it's surroundings look like ? (both top and bottom side)
Best case is damaged tracers or bad resistors/caps on the way to connector itself.
Worst case : Damaged ET4000 chip or RAMDAC.
Here you go. Ignore the messy soldering and flux residue. It may look bad but it's not the problem, I know I did it properly and it happened before I replaced the port too.
L4 and L5 (close to the VGA connector) really seem to be missing 😀
quicknick wrote on 2022-11-01, 23:57:L4 and L5 (close to the VGA connector) really seem to be missing 😀
Any idea what that is, and where I can get replacements? Lots of things like that are missing, it just came that way, but I guess these ones aren't supposed to be. Maybe they fell off in shipping?
From junk PCI video card if you have similar SMD inductors even they look different but close in same location near the VGA connector.
L5 and L4 above the video connector are knocked off.
Cheers,
Great Northern aka Canada.
pentiumspeed wrote on 2022-11-02, 00:47:From junk PCI video card if you have similar SMD inductors even they look different but close in same location near the VGA connector.
L5 and L4 above the video connector are knocked off.
Cheers,
The PCI cards I have have a bunch of them all over the card looking slightly different. Is there any more reliable way to tell?
zconnect wrote on 2022-11-02, 00:19:quicknick wrote on 2022-11-01, 23:57:L4 and L5 (close to the VGA connector) really seem to be missing 😀
Any idea what that is, and where I can get replacements? Lots of things like that are missing, it just came that way, but I guess these ones aren't supposed to be. Maybe they fell off in shipping?
They are choke inductors. You can just jump the pads with solder blobs they aren't really necessary. It's possible someone deliberately configured this card to only display red, or they just fell off or were knocked I guess.
That's 100% the problem, because they are gone G and B are literally not connected to the VGA port
zconnect wrote on 2022-11-02, 00:52:pentiumspeed wrote on 2022-11-02, 00:47:From junk PCI video card if you have similar SMD inductors even they look different but close in same location near the VGA connector.
L5 and L4 above the video connector are knocked off.
Cheers,
The PCI cards I have have a bunch of them all over the card looking slightly different. Is there any more reliable way to tell?
Near the VGA connector, post some photos of your PCI cards is suggested.
Cheers,
Great Northern aka Canada.
Yes you can just jump a wire across them, they help filter some low freq noise but are rarely necessary...
On my Oak 87 based ISA VGA they are just a wire thru a ferrite bead similar to this: https://www.mouser.com/datasheet/2/150/274300 … 112-1512844.pdf
On many PCI cards they have them for the sync signals but not the R-G-B lines iirc (thinking about my S3 PCI cards)...
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
^You need to solder two of these, on your ET4000 card.
As others mentioned, you can just connect two pads to check if signal is there at all.
Horun wrote on 2022-11-02, 01:17:Yes you can just jump a wire across them, they help filter some low freq noise but are rarely necessary...
Not "low frequency noise". They are about removing extremely high frequency noise (significantly above 100MHz). These frequencies are not required at the resolutions those older cards run at. On the other hand, these frequencies can easily be radiated from PCB traces (especially in the monitor) or badly shielded VGA cables. Removing those high frequencies makes it easier to pass electro-magnetic compliance tests.
Yes I mispoke, they are for HF filtering.....most newer VGA cables have them built in on one or both ends....
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
I've intentionally removed the LC filters on most of my ISA cards. They are extremely primitive as video LPF go and I've seen increased sharpness in higher resolutions after the mod.
The OP's card already doesn't have the caps populated (C11-13). If it were me, I'd just remove L3 and bridge the pads for all three inductors with solder blobs.
Alright, working fine now. Thanks for the help.
