What’s the deal with eDP pin pitch adapters?

[commanderf]

Recently ordered a dell precision 7740, to replace my m6800.

 

It has a nice cpu, the 9980HK, but no gpu, and otherwise low specs outside of the big battery.. as such, I’m looking into upgrades.

Currently looking at getting a gpu, along with all the needed cables, required new heatsink, and installing a better display.

 

I have a panel I got ridiculously cheap a bit ago, from a guy selling the display assembly from an x17 r2, since the magnesium back panel was cracked.
It’s the right size, eDP, 360hz, but it appears its .4mm pin pitch. From a bit of hunting around, it seems the precision 7740’s UHD 4 lane panels are .5 mm pin pitch. Model number on it is B173HAN05.2.

(As a side note, I do know the UHD cable only works with the infrared webcam, and I’m fine with just wrapping the lead in kapton tape and having no webcam.)

 

On this forum I’ve seen people use adapters for a discrepancy like this, with some mixed success, with TheQuentincc’s success using one on a 7550, and a fried lcd power line on page 8 of the owner’s thread of the 7#40 series of precisions. 

All of this, has lead me to wonder, what’s the deal with these exactly?

Should I watch out for bad adapters, keep an eye on the pinouts being the same, take extreme care with my install, or just not even bother? From the looks of it, the flex pcb ones don’t have a locking clip which seems like an important part of this..

[commanderf]

It seems they make boards that act like couplers for eDP cables, and a cable with two male eDP connectors, being 40 pin .4mm pitch to 40 pin .5mm pitch.. it’ll be a bit pricey, but I think I can cobble together a solution if it turns out the lack of the retaining clip is the issue with these cheap adapters.

[JadeRover]

Hello, yes they make such flex cables that go from 40 pin .5 to 40 pin .4 I have used such an adapter for my precision 7720 to connect to a 4k .4 pitch lcd. 

 

They are a but flimsy and yes they have no retaining clips. However the sellers provide double sided tape. What you do is insert the male of the cable into the lcd (secure with tape so it won't move). Flip the flex cable around, remove sticky tape and stick it on the top of the lcd controller board. Voilà you converted your lcd to .5 pitch! 

 

Unfortunately I don't have any pictures of the installation. Here is one of the flex cable.