After a thunderstorm, the Palit GeForce GT-240 video card

[UA0JFY]

Hello! After a thunderstorm, VGA and HDMI interfaces stopped working. DVI interface works, but with color distortion: pink instead of white. I did not find any diagrams or boardview on the Internet. Where should you look? Thank you!

[UA0JFY]

Re: After a thunderstorm, the Palit GeForce GT-240 video card

Really nobody faced such problem?

[kaboom]

Re: After a thunderstorm, the Palit GeForce GT-240 video card

Was this a PC connected to a TV/monitor with external cable/antenna connections?

If so, what likely happened is the cable/antenna shield picked up an induced voltage from a nearby hit.
This then came down the antenna cable, into the TV.
Many newer sets do not have a GND wire in their power cord; in this case, the charge picked up by the antenna/cable has no other place to equalize except going to GND via the GND wire (to the electric service) of the PC.

The overall path is down the cable shield, into the TV chassis, up the HDMI into the video card, into the PC chassis, and finally, into the PC's power supply and out the GND wire towards the GND of the building's electric service, where the outside lines are attached. Some of the old wiring didn't have provisions to tie together (bond) all the GNDs (power, phone arrestor, cable/antenna), which results in them rising & falling unequally during storms.

In the US, such bonding jumpers are required per NEC. It's always easy to spot houses without such a jumper, because every spring the same houses have TVs damaged after every "first thunderstorm." That is, until the bonding jumper is installed.

While there are (significant) differences in how secondary voltages are derived in the US vs RU & UA, the bonding principles should mostly apply; HDMI is the coal mine canary, always damaged with poor bonding.
See attached PDF for clarity, especially Fig 800-23.

[UA0JFY]

Re: After a thunderstorm, the Palit GeForce GT-240 video card

Dear friend! I know how the damage happened. Yes, this is a private house and there is no grounding. The question is different: how to find and fix the problem on the video card.

[piernov]

Re: After a thunderstorm, the Palit GeForce GT-240 video card

First suspect would be TVS diodes.

[soumya199929]

Re: After a thunderstorm, the Palit GeForce GT-240 video card

Post a picture of video card near the output ports. Let me see if i can help .

[UA0JFY]

Re: After a thunderstorm, the Palit GeForce GT-240 video card

Good afternoon guys! Sorry, I got sick a little, did not immediately answer. Upon closer inspection of the board from the reverse side, I found missing elements. I'll take a photo later and post it. But to find out exactly what elements are missing and what their values are, you need a diagram of this video card, or rather a boardview.

[UA0JFY]

Re: After a thunderstorm, the Palit GeForce GT-240 video card

Here I took a photo with the marking of the board and in the second photo the missing elements are shown with yellow arrows.