Pipo M9 Pro wifi antenna modification instructions

[rodentkj]

Note: Your mileage may vary. This is just my personal experience and outcome. If you are not comfortable with a soldering iron and electronics you best not attempt this modification.

My tab is the 3G version of the Pipo M9 Pro. It’s no big secret that the Pipo M9 Pro is plagued with wifi problems. Like most others I also ran in to frequent disconnects and poor reception. Hopefully others who have exhausted all of their options can benefit from this thread.
After much troubleshooting on my end which included

• Testing many different cooked roms
• Testing with different wireless AP’s. E.g. Cisco, Asus and Linksys with a mix of B,G and AC radios.
• Tested different combos in the wifi advanced settings (poor connection and battery save settings)

I finally came to the conclusion that this issue is software related and likely will never get fixed, or it’s some type of hardware issue. There has been a lot of speculation / discussion regarding poor workmanship with regards to the coax cable that is used between the wifi radio and the antenna. Since I had exhausted all my resources I figured I might as well try replacing it. In my case the tablet was pretty much worthless to me so I did not have much to lose.

The Russian Pipo M9 Pro forums seem to have the best info regarding the cable modification; however it’s all in Russian. Google Translate does a decent enough job of translating it enough to get an idea what needs to be done. In addition, there is a decent YouTube video (without commentary) that shows the modification.

Here are the two links I am referring to.

http://translate.google.com/translate?u=http%3A%2F%2Ftablette-chinoise.net%2Fpipo-m9-pro-problemes-wifi-coupures-ralentissement-t2648%2Fpage180.html&hl=en&langpair=auto|en&tbb=1&ie=UTF-8

Okay so with all of that said I did the modification and it did indeed resolve 100% of the issues I was seeing. Wireless networks that I was unable to authenticate to now work fine. And zero disconnects.

On to the Modification.
See the two pictures below. It’s pretty self-explanatory. Remove the existing piece of coax wire being used and replace it with two pieces of small stranded wire. And yes I know. Using unshielded wire for this is not optimal. Keep in mind this is a last ditch effort.

NOTES:

1. Watch the YouTube video above. It shows in detail how to separate the case and where the wifi antenna wire is located. Jump to the 1:02 mark when the tear down starts.
2. REMOVE any micro SD & sim cards BEFORE taking the case apart. And keep them removed until you have everything put back together. I destroyed my micro SD slot when attempting to snap the case back together.
3. When putting the case back together start at the top where the buttons, power connector, and audio jack is located. Make sure all of those are lined up first and then work your way down on each side snapping the case back together.
4. The solder had a high melting point (RoHS). The hobby soldering iron I had (unknown wattage) would not melt the solder.
5. The wire I used was from a USB cable that I sacrificed.
6. Separate the two pieces or wire as far apart as you can. See the picture below. Being the wire is unshielded, it’s best to separate them.
7. If you have access to some type of station with a microscope, use it. At a minimum get yourself some type of magnify glass or loop so see what things look like BEFORE and AFTER the modification.

Before


After

[mrleezh]

Hi there! Got a few queries regarding the mod. Based on the video and what I have seen on some other sites. It seems that alot of the wifi/gps issues are caused by the soldering of the wires. I'm no technical person so Im not sure if that's the correct way of saying things.


Can I safely assume that all I need to do is to de solder the thick black wire. And then replace the wire with two thinner ones which are from a USB cable. This way so that instead of one thick cable linking two solder points it will become two thinner cable linking two solder points. My wifi link speed is only about 5mbps. And that's when I'm sitting next to the router already.


Cos from the video and pictures you posted. It sure looks that way. And can I also do the same for the gps? I have issues receiving any satellites at all. None. From Riley to finless to kasty.


Just a note. I got no soldering experience what so ever. The best thing I can do technical is diy my pc. Electrical isn't really my kinda thing. Therefore Im gonna engage the help of others (relatives or pay someone to help me) that's why I got to be sure what is the correct process before I even dismantle the tablet.


Thanks for helping!

[rodentkj]

Hi there! Got a few queries regarding the mod. Based on the video and what I have seen on some other sites. It seems that alot of the wifi/gps issues are caused by the soldering of the wires. I'm no technical person so Im not sure if that's the correct way of saying things.

Yes that does seem to be the case. I can't speak for the GPS stuff. But certainly Wifi, yes.

Can I safely assume that all I need to do is to de solder the thick black wire. And then replace the wire with two thinner ones which are from a USB cable. This way so that instead of one thick cable linking two solder points it will become two thinner cable linking two solder points. My wifi link speed is only about 5mbps. And that's when I'm sitting next to the router already.

Yes, that's the correct procedure. Note that the wifi speed of my M9 is not anything to be excited about. But at least after this mod it's reliable. And I'm more than happy with just that.

Cos from the video and pictures you posted. It sure looks that way. And can I also do the same for the gps? I have issues receiving any satellites at all. None. From Riley to finless to kasty.

One would assume the GPS coax wire could have the same problem. Things are a bit different though as for GPS is receive only. I do plan on modifying the wire on my M9. But first I want to play around the gps.conf file. Without that mod alone the GPS is pretty much worthless.

Just a note. I got no soldering experience what so ever. The best thing I can do technical is diy my pc. Electrical isn't really my kinda thing. Therefore Im gonna engage the help of others (relatives or pay someone to help me) that's why I got to be sure what is the correct process before I even dismantle the tablet. Thanks for helping!

Ya it may be best to have someone with experience with soldering do the work.

[mrleezh]

Just for info. The gps.conf that you mentioned. I have tried it. No go for me. Doesn't even work outdoors. Doubt it's the fault of the conf file though. I strongly believe it's pertaining to my GPS(or lack of it). You can try it first though. But since you got the expertise and equipment to do a solder. I would suggest you go ahead and do it for gps. If you do go ahead with the hardware mod. Please do share it too!

Do note that this is my personal experience. Others have shown success with the simple file added. I hope you have better success than me.

[Finless]

FYI for my tablet all I did was de-solder the ground/shield side of the antenna and this totally fixed it.

We had this very same issue on the MK808 TV stick and de-soldering ground fixed those too.

Now the best way is like the above procedure but I can tell you just desoldering ground also works and did for hundreds of MK808's as well as my M9 Pro

Bob

[rodentkj]

Just for info. The gps.conf that you mentioned. I have tried it. No go for me. Doesn't even work outdoors.

I should have been a bit more clear in my response.

If there is a hardware issue (suspected cabling in this case) then a simple software file is not going to fix it. Although it could improve a little to make it seem like things are better. But yes, I agree with you on your point.

However, once the hardware issues have been resolved then one can move forward with the gps.conf file.
I am 100% convinced that having this file properly setup for the country and region you reside in will help obtain faster and possibly better GPS signal.

With the gps.conf file in place I'd like to at least get GPS somewhat working with no hardware changes so I have a baseline. Then modify the gps antenna wire in my M9 and see if things get better.

Look for the user Cracktech. He has a good handle on things when it comes to the GPS stuff.

[rodentkj]

FYI for my tablet all I did was de-solder the ground/shield side of the antenna and this totally fixed it.
Bob

Right. I read that too.
I figured sine I was going to be in there, and I had the available resources and skills to completely replace the wire, I should go ahead and do that.

[Finless]

Right. I read that too.
I figured sine I was going to be in there, and I had the available resources and skills to completely replace the wire, I should go ahead and do that.

Agreed! If you do it do it right. I was not sure this was my problem so I just did the simple de-solder and put it back together to test it. When it worked I said "heck with it" and left it that way (lazy ). Next time I take it apart I will fix it right anyway.

My GPS works but all sat signals are below 40%. It works but I would like high signal levels. Thus later I plan to do the same as you and try hardware to see if it improves. gps.conf made no difference to me. Once I set my time zone and location via wifi, I get GPS lock very fast.

Bob

[geofferyh]

Sorry to be such a scrooge, but I just have to jump in when I see really bad information being put forward.


The purpose of using coaxial cable (shielded wire) is to keep the signal transmission wire from becoming an antenna too. The original problem was most likely caused by "cold" or bad solder connections or the outer braided jacket being heated to long during installation and melting the inner wire thus creating a low impedance path for some percentage of the WIFI signals. The wires used as a fix are totally wrong, they should be as short as possible to reduce line losses and are color coded wrong. The black wire should have been on the coax shield solder points (ground or -) and the red wire should be the signal wire solder points (+). I suspect the fact that this fix worked at all can be attributed to pure luck more than anything else.

The replacement wire should be coaxial type only, kept as short as possible and soldered very very carefully.

[giouncino]

Sorry to be such a scrooge, but I just have to jump in when I see really bad information being put forward.


The purpose of using coaxial cable (shielded wire) is to keep the signal transmission wire from becoming an antenna too. The original problem was most likely caused by "cold" or bad solder connections or the outer braided jacket being heated to long during installation and melting the inner wire thus creating a low impedance path for some percentage of the WIFI signals. The wires used as a fix are totally wrong, they should be as short as possible to reduce line losses and are color coded wrong. The black wire should have been on the coax shield solder points (ground or -) and the red wire should be the signal wire solder points (+). I suspect the fact that this fix worked at all can be attributed to pure luck more than anything else.

The replacement wire should be coaxial type only, kept as short as possible and soldered very very carefully.

I completely agree.
I'm going to replace on my Pipo M6pro the wi-fi AND 3G coaxial cables with low loss aeronautics coaxial ones to improve signal strength!
I hope that a slightly increase in cable diameter can fit inside my tablet!
I'll do it probably next week-end...

[Finless]

All I can say is if it works ENJOY! de-soldering the shield worked for me. I know by design that is not right but like I said..... It works and fixed my wifi signal issues.

Bob

[rodentkj]

Pure luck. Bla.....
You give the impression that not using a piece of coax for the fix can cause some type of irreparable damage to the tab. Worse case the wifi still performs poorly.

Sure using coax would be the best option. No doubt. And if you have a piece use it. With that said most people will not have that available to them. So I went the down and dirty route, hail mary if you will.

We could go back and forth about this but the end result is this modification made my worthless M9 useful again. Other have reported the same result. And if others can benefit from this then it's worth posing the info.

Black, red. Red, Black wire color. Who cares. As long as the wire is connected to the correct pads, the color is pointless.

[giouncino]

Pure luck. Bla.....
You give the impression that not using a piece of coax for the fix can cause some type of irreparable damage to the tab. Worse case the wifi still performs poorly.

Sure using coax would be the best option. No doubt. And if you have a piece use it. With that said most people will not have that available to them. So I went the down and dirty route, hail mary if you will.

We could go back and forth about this but the end result is this modification made my worthless M9 useful again. Other have reported the same result. And if others can benefit from this then it's worth posing the info.

Black, red. Red, Black wire color. Who cares. As long as the wire is connected to the correct pads, the color is pointless.

This is not completely true, if the input/output part of TX/RX wifi doesn't see the correct characteristic impedance, it is possible to destroy the wifi receiver. Not for sure, it depends on how is good the wifi integrated circuit.
For example, if you use a wi-fi router without the antenna properly connected you can damage it. It has heppened to me on one awus036h wifi adapter modified by me (in not a good way..), after a while (less than one month) it was no more able to connect to wi-fi.

If you want to do a good job you can easily find in internet a suitable low loss coaxial cable...

[Nordo]

I completely agree.
I'm going to replace on my Pipo M6pro the wi-fi AND 3G coaxial cables with low loss aeronautics coaxial ones to improve signal strength!
I hope that a slightly increase in cable diameter can fit inside my tablet!
I'll do it probably next week-end...

Can you post your results.

BTW, I totally agree with the theory that the interconnect should be shielded.
It's possible that the person soldering the coax wire has not been properly instructed (or wasn't listening).

[giouncino]

Can you post your results.

BTW, I totally agree with the theory that the interconnect should be shielded.
It's possible that the person soldering the coax wire has not been properly instructed (or wasn't listening).

Of course!
I will receive a new battery for the tablet soon, I would like to open my tablet one time only. Then as soon as the battery arrive I'll do all the soldering and cable mods.
Hopefully next week-end.