Hi,

I've got this old Tseng Labs Ultra Pak card.

https://imgur.com/gallery/vP5YYYN

Haven't found much info on it, but I suspect an IBM MDA alternative featuring LPT, COM1, COM2, a real time clock (the card also included a battery that had been removed by the original owner)

The problem is nothing is shown on the display when the computer starts. Just 1 beep (long) and 2 beeps (short). Same computer works fine with an IBM MDA card.
There was definitely some corrosion on the card as you can see from the pictures. Here's what I did so far :

• I cleaned the impacted area with vinegar / IPA.
• I checked the 3 tantalum caps (10mF, 16V). These turned out fine.
• I removed some of the corroded chips to check the traces underneath the chips. Nothing suspicious found.
• Tried to read the EEPROM chip (2764) and was able to read the data off it using my universal eeprom programmer.
• Removed the memory chips and tried them in another working card (memory chips are ok)

Are there other things I can check / verify ? I suspect that all of those logic chips / small 10pF caps aren't that error prone.
What would be a good way to debug this further ?

Thx.