Can anyone tell which A500 modification this is? (Noob)

[scuzzb494]

Hi there Amiga enthusiasts,

I just started collecting and working on some Amigas 500, so I probably have a noob question:

I have one dead A500 rev 5 board (most likely ram chip error) but I also noticed a modification to the board. It looks like an added transistor just below Denise, but I don't know what it represents.

I also noticed it some Amiga 500 repair video's  on Youtube, but it is never pointed out and explained.

Here is an image:


Any info on this I would appriciate!

Greetings,

Megantonneke

Hadn't realised what it was for but have noticed it on some of my motherboards

http://www.scuzzscink.com/amiga/scuzzblog_november17_2/car_sbd_091117_38.jpg

http://www.scuzzscink.com/amiga/scuzzblog_november17/scuzzblogdnovember17_0903.htm