你用线是否ＵＬ２９１９规格线，是参考ＵＬ标准要求，参考ＵＬ７５８可以了．

UNDERWRITERS LABORATORIES INC. APPLIANCE WIRING MATERIAL
Subject 758 　　Section 2 Page 2919 　　　　　　　　Issued: March 22, 1978
　　　　　　　　　　　　　　　　　　　　　　　Revised: Feb. 12, 2001
　　Style 2919 Low Voltage Computer Cable.
　　Rating 80°C, 30 Volts.
         Insulated Conductors　：No. 40 AWG minimum. Labeled or complying with Manufacturer’s　AWM Procedure having a minimum rating of 80°C, 30 V.
          Assembly 　：Consists of two or more conductors, twisted pairs or groups of  twisted conductors twisted together. The conductors or groups of conductors may be laid parallel forming a flat,oval or round cable. The lay of the conductors is not specified. A barrier layer and/or fillers are optional. Manufacturer shall maintain a complete description of each assembly. May use same or mixed AWG size.
            Covering      (Optional) - A 6 mil or heavier PVC covering may be extruded over the conductor assembly.
           *Shield     Optional.
           Jacket PVC - Class 43
           THICKNESS (MILS)
#Dia of cable under jacket               Minimum                 Minimum  

 in inches                                          Average                    at any point
_____________ ________ ____________
0.425 or less                                             30                                  24
0.426 - 0.700                                             45                                    36
0.701 - 1.000                                              60                                   48
1.000 - 1.500                                             80                                      64
1.501 - 2.500                                             110                                 88
2.501 and larger                                        140                              112
# - Major dia if cable is flat or oval.
*Standard                               Appliance Wiring Material UL 758.

2919  VGA现在已被HDMI取代了，没有多少工厂在做此线了。