yashsingh1/xdaforums huggingface dataset:
[MTCD  Android Head Units Q&A] scorillo_ro:
This should get you in OTG loader mode. Did not work for me, I want to try the OTG maskrom mode. I hope [MENTION=4974080]marchnz[/MENTION] will show us exactly the paths than need to be grounded, maybe draw some lines over his picture.
[MTCD  Android Head Units Q&A] Malle355:
Ok thanks. I first try it. If its not working I must wait if you guys can help with the maskrom mode right? Thank you guys for youre help :o

Edit: Just tried the OTG Method but also not working for me. Windows not reconizing my device. [MENTION=4974080]marchnz[/MENTION] Can you please show us in this Picture what to do to get it working on our px5 device?
[MTCD  Android Head Units Q&A] marchnz:
Your connections look OK, but missing OTG_DET pin 28, which has +1.8v on it when connected to USB. (Detects when OTG USB is connected.)

As I have a jig made from a working motherboard, I am awaiting a header to mock up like you guys. I'll try making one out of wires like you have over the weekend and let you know.

I'm very keen to see more people get OTG so there's more people capable of helping out others that are that are stuck - others that are unable to make a jig might then have someone located closer and save on freight or having to replace their SOM :)
[MTCD  Android Head Units Q&A] scorillo_ro:
[MENTION=4974080]marchnz[/MENTION] I want to expose my tracks between the kingston emmc and the PX5 processor to enter maskrom. Please draw some lines on the picture of your exposed tracks to see which one needs to be grounded. Thank you!
[MTCD  Android Head Units Q&A] scorillo_ro:
Or you can edit this one
[MTCD  Android Head Units Q&A] marchnz:
Make sure your otg_det is working - when USB connected USB will feed 1.8-3.3v to enable the SOM to detect OTG USB connected.
[MTCD  Android Head Units Q&A] Malle355:
Report if you tried this. Will also try this later to get my px5 back working.
[MTCD  Android Head Units Q&A] scorillo_ro:
Hopefully it will activate OTG when entering maskrom. If you remember, my KLD motherboard has external OTG connector. I’m also waiting the 2mm headers to come, so for now I will try with the SOM connected to motherboard, not standalone.

It is getting late here and I’m too tired to try this now, but I will do it in the next days.

I really appreciate your support!
[MTCD  Android Head Units Q&A] scorillo_ro:
Did not had much time before going to work, but I wanted to take advantage of the beautiful sun light in the morning to do the step I was most afraid of...

This is how my exposed tracks looks like.

This evening or at last this weekend I will try to enter in the maskrom of my PX5. Unfortunately I don't have any tweezers, so I must think on what to use to do the actual grounding. Those tracks are so thin!

Later edit: Bought these fine tweezers from an electronics store near my work place.
[MTCD  Android Head Units Q&A] Malle355:
Also have done this. :o

Can't get it working on my device . I just put 1,8V in but my device is still not detected from windows. Also have done this with the first four emmc lines and a tweezer but nothing happening :(
[MTCD  Android Head Units Q&A] scorillo_ro:
Did not work for me either.
[MTCD  Android Head Units Q&A] dottorniù:
Hello everyone, sorry for my english but use google translate ....

First of all thank you very much to Marchnz for the incredible work done.

During the update from Oreo stock to Malaysk Oreo I flashed malaysk recovery and after removing the sd the radio has no signs of life even changing sd or with different sdupdate. Previously with the same method I had moved from Android 6 to 8

At this point I think my only chance is to try with the jig

Before proceeding, however, I would have some doubts to clarify

I attach a picture of my som that has only 72 pins, in the picture I indicated what my test is pin 1 and 72.

Looking for some feedback with the multimeter I have identified the destination of the following pins

71, 72 -> usb rtl8723BU

70, 66, 56, 12, 10, 6, 5, 4 -> GND

17 -> touch int

18 -> touch scl

19 -> touch sda

29, 30 I attach image

So despite my pins are less it seems that the numbering matches with the one posted by Marchnz. Quite right?

For the usb connection 30 is d + and 29 d- right?

Thanks for any answers

I can not insert images, please open them with the links below .... sorry

SOM-->h**p://i66.tinypic.com/oky9oh.jpg

PIN29_30-->h**p://i67.tinypic.com/117a8g8.jpg

---------- Post added at 08:40 PM ---------- Previous post was at 08:29 PM ----------

You may have reversed date + and date -?

if you check the pattern on this page h**p://infocenter.arm.com/help/topic/com.arm.doc.faqs/ka13245.html

you can see that DM corresponds to date minus and dp to data plus
[MTCD  Android Head Units Q&A] Malle355:
Yes thanks for that but already tried it.
[MTCD  Android Head Units Q&A] dottorniù:
Good morning, after a night to study on this thread are even more confused ....

first question:

in the first post we see the connection scheme between mcu and psu / usb

pins 9,15,20,28 are all 3.3 volts but no one with a logic resistance of 1 or 0 is chosen

In the post instead quoted (if I misunderstood) you say that the pin 20 must be put to 3.3 through a pullup resistor. Quite right? since 10K

and 9.15.28 always pullup?

and if 15 goes to direct gnd or through pulldown?

Could you post a picture where you see how you connected the som?

Probably for you and the other people who read the thread are things taken for granted, but before I give tension I prefer clear any doubt .... thanks for your patience.

Second question:

I can no longer find where I had read it but I seemed to have seen among the procedures that a pin was fed only until the som was not recognized by the pc. Can you tell me what it is or if I'm wrong?

Thank you all.
[MTCD  Android Head Units Q&A] Malle355:
Hi,

thanks for your help. No it isn't a "pin" that you need to connect. You can try to ground the first four emmc lines with a tweezer or something else like on this Picture.
[MTCD  Android Head Units Q&A] scorillo_ro:
What you are referring as pins 71 and 72 are in fact pins 74 and 75. Look at the attached image provided by @marchnz which is cropped from the original schematics and has the supposed required pins highlighted in colors. The attached pdf contains two tables made by me witch may help you identify the pins more quickly. The colors are the same as in marchnz's schematics.

I don't know what 71,72 and 73 from the schematics are, but because they goes to GND, they might be the three mounting holes of the SOM...

Remember that nobody actually succeeded to do the OTG using just the SOM...

Marchnz used an old spare GS motherboard which he modified to make a JIG.

I managed to enter loader mode OTG but not on my bricked SOM but on an functional SOM and using my KLD unit which has an external connector used for OTG. I have not been able to enter maskrom mode by exposing and shorting some paths between emmc and the px5 processor.

Marchnz is waiting for some headers in order to try to simulate his JIG without using his old motherboard, so this is still a work in progress.

But in the end I'm sure that things will become clear and everybody will be able to do OTG on PX5.

Be patient and don't give up, your tests and experience may help all of us.
[MTCD  Android Head Units Q&A] scorillo_ro:
deleted
[MTCD  Android Head Units Q&A] scorillo_ro:
Interesting SOM.

My bricked SOM is version 4 and looks different. I didn't took off the heat sink of my new SOM to see if it is similar to yours, mine is blue, but I'll do it next days.

I wonder what are those pads near the tracks between the emmc and px5 processor... Might be for entering maskrom mode?
[MTCD  Android Head Units Q&A] marchnz:
Might be, keen to try?
[MTCD  Android Head Units Q&A] dottorniù:
Thank you for the exhaustive answer,

now I understand the situation better and I believe that I will proceed to the motherboard mod. I thought marchnz had already tried ...

I had also noticed those two pitches, one goes to GND and the other is connected to the first track of the emmc. I tried to close them with tweezers but nothing happens.

I put other photos so if you see errors maybe give me a suggestion ...

wire colors:

orange 3.3V

red 5V

Black GND

Green DM

White DP

To feed the som I used a psu atx

Meanwhile, the motherboard mod.

jig1 h**p://i68.tinypic.com/23h63yc.jpg

jig2 h**p://i68.tinypic.com/124bqe9.jpg

jig3 h**p://i64.tinypic.com/34qpslu.jpg

jig4 h**p://i63.tinypic.com/15g2t8n.jpg

pad som h**p://i64.tinypic.com/2w4ijqs.jpg

full album link h**p://it.tinypic.com/a/abpe8k/4
[MTCD  Android Head Units Q&A] scorillo_ro:
PX5 SOM rev8.0 MaskROM

I have the confirmation that those round pads near the tracks between PX5 processor and the eMMC are for entering MaskROM!
[MTCD  Android Head Units Q&A] scorillo_ro:
PX5 SOM rev4.0 MaskROM

Tracking the MaskROM pads on the rev8.0 SOM I found that exposing the tracks between the PX5 processor and the eMMC is not necessarily needed for the rev4.0 SOM. Take a look at the attached pictures.
[MTCD  Android Head Units Q&A] scorillo_ro:
Your JIG looks very good even if it is not working yet.

Why don't you try to track the OTG pins of the GL850G to see if you already have a hidden OTG connector like my unit have?

PS. If I remember correctly, after 10 posts on the forum you will be able to directly attach pictures. Please upload them here when you'll be allowed.
[MTCD  Android Head Units Q&A] dottorniù:
update:

raise the pins of the USB hub removed the pin 28 of the som from the motherboard and brought the 3.3 to the pin 28 of the som.

I soldered a USB cable under the motherboard, connected the USB to the PC and fed the motherboard ... but still nothing is detected by PC.

Also in this case I have to try to connect pin 28 to GND?

Is PC detection immediate or does it take a few minutes?

[MENTION=4768815]scorillo_ro[/MENTION]

fantastic discovery!

to activate maskrom join pins before power or after?

Thank you very much!
[MTCD  Android Head Units Q&A] scorillo_ro:
I first tried to lift pins 27 and 28 of the GL850 USB hub and directly connect the white and green USB wires to the SOM. Also wired CTL_RECOVERY pin on the SOM in order to connect it to 3.3v. Now I think that this approach was a bad idea!!!

I ended soldering back both pins (27 and 28) because I have found the OTG connector on the back side of my unit.

The maskrom mode is activated almost instantly after the unit is powered on with the round pads already shorted. It will take one second or two at a maximum to hear the windows chime for founding new device.

Remember that the first time the device will be discovered, windows will start installing the rockchip drivers for the corresponding USB port. This might take a long time and the SOM will eventually give up waiting for the connection and will exit the maskrom mode, trying to boot from eMMC. Don't worry, windows will finish installing the drivers even if it will report that the device was disconnected. Power off your unit, short the pads, power it on again. This time the device will be properly discovered and you will be in maskrom mode for a little bit more time.

As [MENTION=4974080]marchnz[/MENTION] already said, the maskrom mode will be available for only about a minute. My stopwatch showed a minute and about 10 seconds when the device got disconnected from windows. So you don't have enough time to flash a full update.img firmware. You can use one of the sdupdate.img files kindly provided by [MENTION=3556393]SkyBeam2048[/MENTION] on his google drive here. I will suggest to use the one for android 6, but android 8 will also work.

I think [MENTION=4974080]marchnz[/MENTION] can provide you more details on how to use the Rockchip Batch Tools software.

Later edit: you should release the maskrom pads after the windows device connected sound
[MTCD  Android Head Units Q&A] dottorniù:
maybe I found the usb-otg pins ... are set to those for the usb internet key.

In the cable provided with the two pins are empty, checking with the multimeter those pins connect to the GL850G pin 8 (usb-DM3) and 9 (usb-DP3)

Also in yours are they in the same place ??

Update:

update:

* I brought the motherboard back as originally

I put a button connected you have pad of the SOM to start masckrom.

I connected the usb to the pc and powered while holding the button pressed but still nothing.

I turned off, unplugged the usb and restarted to check the voltages on the SOM and I saw that pin 15 (CTL_WEKEUP) stands at zero. it's normal?
[MTCD  Android Head Units Q&A] scorillo_ro:
My unit is different. It has all 4 pins used by USB: GND, DATA+, DATA- and VCC

https://xdaforums.com/showpost.php?p=75777649&postcount=90

Have you also connected the ACC to 12 volts? I have both 12v wires connected at the same time (red and yellow) when powering on with the mask pads shorted.

LE. DM3 and DP3 are normal USB port. You should look for 27 and 28 (OTG-DM and OTG-DP).
[MTCD  Android Head Units Q&A] dottorniù:
Yes, +12 yellow and red, on the other pins tested (1,2,3,4,5,6,9,20) the voltage is correct.

For the first test I used usb 1 that measuring with the multimeter is connected to pins 27 and 28 of GL850 and nothing happened.

Checking the wiring diagrams posted by marchnz I found that the transil diodes D5 and D8 are connected to otg-dp and otg-dm, on the motherboard I found the position of the diodes and from that they went back to the pins of the GL850 and the output ones on the back of the stereo.

Later or tomorrow I will try to connect the USB cable directly on the pads and see if I'm lucky but I start to suspect that the problem is just the motherboard ....

I add the link to a photo that simplifies my explanation, to better understand it should be downloaded and enlarged.

h**p://i66.tinypic.com/2rw0rr6.jpg
[MTCD  Android Head Units Q&A] marchnz:
Brilliant! Nice work.
[MTCD  Android Head Units Q&A] marchnz:
Hi,

What happens is that the MCU watchdog tries to reset the SOM by powering it off/on, when it doesnt receive a response from the SOM. I found a workaround, to keep the SOM powered up during the process.

The workaround: U22 [MP584] add a temporary 470Ohm resistor between Pin 2 of U22 (enable) and +3.3v.

This will keep the SOM powered ON.

-M
[MTCD  Android Head Units Q&A] marchnz:
Hi,

See this thread for making a simple OTG cable from a USB cable and two resistors.....

https://xdaforums.com/android-auto/...px3-5-headunit-mod-recover-flash-som-t3766892
[MTCD  Android Head Units Q&A] scorillo_ro:
Very nice!
[MTCD  Android Head Units Q&A] adioperator:
Hello friends,

Today I got into trouble.

I wanted to root to my Android 8.0 drive using the method:

After install the update from the SD Card, remove the card and reboot the radio, does not load Android and sometimes enters Recovery Mode like in video

https://www.youtube.com/watch?v=llz_H-6Vw2M

My head unit model:

https://photos.app.goo.gl/6Mj3SYc1vJD5KRY72

What should I do now?

Thanks!
[MTCD  Android Head Units Q&A] scorillo_ro:
Now you should apply system update from that recovery mode.
[MTCD  Android Head Units Q&A] akin:
Hi all

I have had a bad day and my head unit with a brand new PX5 4gb ram and 32 gb storage is turning on but nothing appears on the screen. The head unit was fine until I decided that OREO was for me. So I can still do a reset IE hold the power button until the 3 flashes and press once more for recovery but its just sits at a black screen.

So hopefully just need the SOM reflashed ? or I could just buy another SOM. I will try and make a OTG usb cable up and see if I cant recover it that way. My main question is based on the symptoms does this sound like I just need to reflash the SOM or maybe somehting more sinister ?

Appreciate any guidance offered
[MTCD  Android Head Units Q&A] marchnz:
Use OTG to recover. If SOM does not go into OTG Loader mode, force MASKROM. Use Android tool - update - and specify your Android 6 [sdupdate.img].
[MTCD  Android Head Units Q&A] dottorniù:
I recovered two units that did not start anymore (black screen) sending the som in maskrom.

For the first it was enough to use the batchtool and rewrite the sdupdate.

For the second I had to use RKDevTool because the writing always stopped at 2% and then before doing the complete writing I had to do EraseFlash.

Now both units work perfectly with Malaysk's OREO 8

but on both at the start of recovery I see an error on loading some partitions (see photo) is normal? can it be remedied in any way?
[MTCD  Android Head Units Q&A] scorillo_ro:
I think that we all have those messages, or at least the majority of us... so, no panic, you are all good! :)
[MTCD  Android Head Units Q&A] akin:
I made a cable up but cant get my PC to connect to my old working PX3 SOM so not sure what I am doing wrong have check voltages and have them etc maybe android tools doesnt like win 10, marchnz maybe message me your address and I will send over my PX5 board and see if you can get it going.?

Thanks
[MTCD  Android Head Units Q&A] scorillo_ro:
Don't quit so easy, maybe we can help you and others learn from this experience!

Please describe with more details what is not working for you.
[MTCD  Android Head Units Q&A] akin:
OK made up the cable as per marchnz instructions I even wne t and bought some 12k and 22k resisters and wired up a USB cable. I then downloaded the Driver install pack as per his post and installed. The issue at hand is Android Tool does not see the SoM, I have double checked that I have the correct voltages at the board. I ok with a multi-meter as I done a lot of 12 volt in my 4wd. So the basic issue is I cant see the board in WIndows 10 to push out the required update.img file. Now I did have sniff around the maskrom but from what I can find I am unsure on what exactly I need to do here.

One caveat is at the moment I am trying out the connectivity side on my old PX3 board (works fine) first before I demolish half my car and pull out the PX5 board so a question is the pin outs the same between the 2 ?

Cheers
[MTCD  Android Head Units Q&A] scorillo_ro:
Attach some SoM pictures. If your SoM have a heatsink, make a picture without it.

But yes, PX3 and PX5 should have the same pinouts!

Do you hear a sound when you attach the USB plug to the PC?

What voltage do you have between the GND and the middle of the resistors? You should have between 1.8 and 3.3 volts to be able to apply a logical one to CTL-Recovery and USB-Det
[MTCD  Android Head Units Q&A] akin:
NO sounds at all and I have just enable my personal webspace with my ISP so will upload pics once done should be about 15 mins or so

---------- Post added at 09:48 PM ---------- Previous post was at 09:45 PM ----------

Only have 1.14 volts....back out to the shed for me :D

For clarity I used a 12k and 22k resisitor
[MTCD  Android Head Units Q&A] scorillo_ro:
Yes, I think is too low and that's why the SoM does not enter recovery/loader mode or does not go into USB OTG.

12K and 15k should give you 2.8 volts ...
[MTCD  Android Head Units Q&A] akin:
Yep will go and buy a 15K one tomorrow

And not as "pretty" as your setup :D

http://members.aussiebroadband.com.au//kingy/IMG_20180327_214122.jpg

---------- Post added at 10:02 PM ---------- Previous post was at 09:57 PM ----------

[/COLOR]and thanks too
[MTCD  Android Head Units Q&A] scorillo_ro:
The look does not matter :cool:

It is important not to make short circuits between wires :fingers-crossed:

Good luck!
[MTCD  Android Head Units Q&A] akin:
ok re did the usb cable and I am now connected just working out what firmware to flash etc :D

http://members.aussiebroadband.com.au//kingy/firmware.JPG

---------- Post added at 11:14 PM ---------- Previous post was at 10:59 PM ----------

[/COLOR]Should I be brave and flash a oreo rom ?
[MTCD  Android Head Units Q&A] scorillo_ro:
Please attach the pictures, do not put them directly into your messages!

If you can, edit all your old posts with big pictures. That way the thread will be more readable.

To answer your question, use a sdupdate.img file. If you want, you can use a full (1.3 gigabytes) android 6 image, or you can use an android 8 sdupdate.img file (around 100 megabytes). Just keep in mind that those android 8 images do not contain the full system image, so you will need to put the SoM back in the unit, access recovery mode and use "apply update system" to actually install the android 8 system (update.zip).

Now that you have a working OTG, you can play safely with the images...
[MTCD  Android Head Units Q&A] akin:
Winning...cant thank you guys enough...now to fix the BT cant find my phone but should be easish enough.

OREO 8.0.0 up and running
[MTCD  Android Head Units Q&A] scorillo_ro:
Another success story... Congrats!
[MTCD  Android Head Units Q&A] ToastedAndroid:
Hi, I'm desperate for a success story if any of you could help! I have made the jig up using a 2.2k and 3.3k resistors going off another thread this apparently would work also and i couldn't get access to a 15k resistor without putting about 6 resistors in series. Im pretty sure my wiring is correct and continuity seems to be fine on the USB side to the board. but when i connect it to either of my laptops i don't get anything (Connecting them to the port with the little lightening icon). I also notice after connecting everything up the resistances drops to around 1.5k in the 2.2k and 1.6-1.7k in the 3.3k resistors is this normal as I'm no electronics genius.

https://lh4.googleusercontent.com/t...U0-1bOmY04Hwo8oGraS_4XjzAPbcnZs=w1715-h655-rw
[MTCD  Android Head Units Q&A] trap63:
what means?.....

unable to restore to 6
[MTCD  Android Head Units Q&A] dstyp:
Been writing in other threads but no solution and this fits my problem so trying here instead of creating a new thread. I wanted to update to Malaysk Oreo ROM and failed.

I've got a MTCE_LM_V2.75_1 with buttons and it's stuck in a boot loop. It will not boot into recovery or boot successfully from a sd card either. It's a fairly new PX5 4GB so I want to avoid opening it to maintain my warranty.

The problem now I believe is that I'm not able to boot from SD into a Recovery menu. Previously I could reach the stock recovery menu by holding power til lights flash - release power then pressing power a couple of more times. This would provide the built in stock recovery menu. On that menu - if I chose "reboot" and inserted the bootable SD card it would boot into the bootable card recovery menu.

I was never able to update though since the card didn't boot correctly. It did however erased my stock os and it's gone. I also tried to choose a few erase options in the stock recovery and this rendered the stock recovery unbootable and the device is now stuck in a boot loop.

Question is - is there any button combination that I've missed that would produce the same behavior as choosing "reboot" in the stock recovery that would boot the sd card recovery if the card was inserted?

Current status:

- boot unit - shows boot logo from stock and is stuck in boot loop (cant find recovery partition or something similar)

- boot unit with bootable sd card - shows boot logo from sd card - shows it forever - reboots after like 20 minutes

I've tried the following to boot from the sd card and spawn the recovery menu:

- Hold power til it flashes and release

- Hold power til it flashes and press again once

- Hold power til it flashes and press again multiple times (this would always spawn the stock recovery menu back when it worked which made me sure I could reach recovery)

- Hold reset 10 sec and release

- Hold reset, press and hold power, release reset. Wait. Release power. (this sometimes just renders the unit screen black with button lights on)

- Hold power and reset for 30 sec, release reset keep holding power, release power

- Disconnected power entirely from the unit for a long time and start up with sd inserted

- Short black and yellow pin for a minute and connect to power

Any ideas?

I have not tried connecting a keyboard. I have a usb keyboard I could try. Are there any keyboard combinations that could work?