rodarkone
Hello all, 
 
I need a little bit of help, today I have purchased a GM550W SFX PSU but I don't have the any VGA video cables.
 
I own 2 other EVGA PSU's (both are 1600 T2)
 
Are the VGA cables compatible ? maybe somebody from EVGA can answer clearly as apparently the cable set (https://www.evga.com/products/product.aspx?pn=101-CK-0850-B9) sold by EVGA can be used with any power supply but I could not find any information.

I'm a bit confused by your post. Are you saying the 550 GM PSU you bought didn't come with VGA cables? It shows in the product page it comes with two. To answer your question the T2 cables should be compatible. I'm finding it unfortunate the compatibility tab no longer shows any useful info, on many products. Hopefully it's something EVGA is working on.  It is always good practice to use the cables that came with the PSU purchased. Be sure to register your new PSU for full warranty support. 
If you wanted to contact EVGA and talk to them, I will link the contact info: https://www.evga.com/about/contactus/
 
Edit: Here is an informative post from one of our very knowledgeable members Bob16314, he mentions the cable set and pin outs. 
https://forums.evga.com/I-need-help-Looking-for-a-pinout-for-GM-550w-SFX-m3206002.aspx