I just bought a cheap Thunderbolt to VGA conversor, for a macbook pro. It didn't work at all so I decided to open the case. I found a silicon lump and most of the cables just hanging there.

Just as an exercise, I want to sort out which cables I need to solder onto which pins. Here are some pictures with what I got.

DP to VGA back

DP to VGA front

I've looked for VGA pinout and Thunderbolt pinout. Also found this link about Apple's MiniDisplay port, but I really don't have much clue where to look next.

Update 1

Here's a picture showing chip information on the board. As mentioned on the comments, my bet is that this is a standard DisplayPort to VGA conversor board. But I haven't found any info on it.

Chip detail

Text on chips:

Big chip (Parade):

C 1420

SmallerChip (BergMicro):


Update 2

The Parade chip/board is described here: www.paradetech.com/products/displayport-format-converters/ps8617/ (not enough rep to post more links).

I believe the first question to answer is the cable color correspondence of the ThunderBolt end, I don't know if there's a standard, or if that's possible without tearing the wire apart.

  • 2
    Unless you know what the chip in the middle is doing, you don't have a snowball's chance in hell of getting it right without looking at another. – Ignacio Vazquez-Abrams Nov 1 '14 at 20:13
  • I would first check those numbers at the connector P1 on the PCB... there are 20 pins in the displayport connector... could those numbers refer to the DP pins? Hmm, I took a look at the numbers myself, and they don't seem to make any sense, compared against the pin numbers of the displayport connector... too bad. – PkP Nov 1 '14 at 20:19
  • My guess is that it is a common DisplayPort to VGA board. Based on what is written at the back. No idea about cable color correspondance though. – Sergio Basurco Nov 1 '14 at 20:20
  • If you get the wires sorted out and if you believe your time is worth less than the cost of a new one, have you ever tried to manually solder this type of thing before? It is incredibly hard. You need a soldering iron with the right wattage and a micro tip. It is very difficult to not create solder bridges between the contacts unless you use solder resist on everything you do not intend to solder at the moment and do one at a time. If you just tin and touch for a joint, it won't be reliable or mechanically strong and may break away when you assemble it. Micro-soldering is a special deal. – fixer1234 Nov 4 '14 at 22:13
  • My actual goal was to learn about how hard this was to fix. Provided I could get the theory straight. But thanks for the advice, I'm actually desisting. Best of luck to the next one that tries to go down this road! – Sergio Basurco Nov 9 '14 at 17:16

The number that is shown next to each pads, is the pin number of a normal sized displayport connector. You can find the relation between the normal and mini sized connector at wikipedia. Next you have to identify the numbering for for each wire - for that you can use a multimeter.

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