VOGONS


First post, by lalakobe

User metadata
Rank Newbie
Rank
Newbie

Hello guys, I need some advice from you/

So today I got old IBM CGA video card by mail and wanted to check it in my 8086 machine.
Upon power up, one of the capacitors blew up!

4.jpg
Filename
4.jpg
File size
323.46 KiB
Views
152 views
File license
CC-BY-4.0

Back of the board:

3.jpg
Filename
3.jpg
File size
452.49 KiB
Views
152 views
File license
CC-BY-4.0

This is one of the three-legged tantalum capacitors that were popular back in the day, right?
Original was 16V 10mf.
Can I just replace it with modern two-legged capacitor 25v 10mf I have?

1.jpg
Filename
1.jpg
File size
145.69 KiB
Views
152 views
File license
CC-BY-4.0

Reply 1 of 2, by Horun

User metadata
Rank l33t
Rank
l33t

Yes but you need to check which is ground, most 3 leg Tants the outside legs were ground and the middle was positive (not sure why they did 3 legs since the grounds were typically internally shorted except to use as a feed thru). Use a Digital ohmmeter and check that the outside leg holes are truly ground, should be 1 ohm or less. Then you need to wire the two grounds together and attach the new cap.

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.

Reply 2 of 2, by kdr

User metadata
Rank Member
Rank
Member

I'd recommend using a 10uF 25V tantalum cap as the replacement. It'll keep the card looking more authentic and will be better suited for smoothing out high-frequency switching noise than a generic electrolytic. It's not difficult to find a suitable (2-leg) tantalum.