Ordering EVO PCBs at chinese manufactures questions and help

[DigitalJedi084]

2 hours ago, trueno92 said:

Are you also from the Buffalo bro do u play pinball channel? 

nah not part of the “Buffalo Pinball” twitch group- I didn’t even think of the name correlation at first...now I’m too far deep to change usernames.

 

I am in the buffalo league with all of them though, so you may have seen me once or twice in their streams. Great guys! Some Amazing collections 😍

[Tinkertilter]

ok, I am about to take the plunge and do my first set of 5 boards.
I found that Ali Express has the chip STM32F427VIT6 and it is wayyyyyy cheaper than PCBWAY. $75 dollars vs $12... 😮

 

Any objections to not buy the Ali express one and solder it in myself? 

[Tinkertilter]

12 hours ago, Tinkertilter said:

ok, I am about to take the plunge and do my first set of 5 boards.
I found that Ali Express has the chip STM32F427VIT6 and it is wayyyyyy cheaper than PCBWAY. $75 dollars vs $12... 😮

 

Any objections to not buy the Ali express one and solder it in myself? 

well, I guess I will be reporting back with an answer myself in a few weeks once I receive all the parts. I ordered the chips from Alibaba for a lot less than what PCB was charging me. Yes they need to be soldered by myself and this is something I can do, however, I can understand how this could be an issue for most people. that and the risk of getting bad components? I do not know... I will take the risk and see what happens. 

I have also ordered the pcbs and LEDS. Wish me luck!

[SpaceGambler]

Hi Guys
I just received 5 EVO boards and they all seem to have the same problem.
The lower half of the screen does not have any green at all.
This shows during all modes where the other colours look wrong and when I go into screen test, red and blue work ok across the full screen but the green only shows on the top half.
Any suggestions on where to look?

[OzStick]

On 11/3/2021 at 2:05 PM, Tinkertilter said:

ok, I am about to take the plunge and do my first set of 5 boards.
I found that Ali Express has the chip STM32F427VIT6 and it is wayyyyyy cheaper than PCBWAY. $75 dollars vs $12... 😮

 

Any objections to not buy the Ali express one and solder it in myself? 

Did you get onto your "agent" at PCBWay and ask whether you can supply them with the  STM32 for THEM to assemble?

[ItemKiller]

On 11/18/2021 at 11:20 AM, OzStick said:

Did you get onto your "agent" at PCBWay and ask whether you can supply them with the  STM32 for THEM to assemble?

I did, they say Yes.

[OzStick]

On 11/22/2021 at 7:00 PM, ItemKiller said:

I did, they say Yes.

Have you gone ahead with such an order as yet? I'm sure many of us would be interested to know of someone who has purchased "clone" STM32 chips from AliExpress for PCBWay to use on their boards AND be successful in having those boards operate correctly!

[ItemKiller]

3 hours ago, OzStick said:

Have you gone ahead with such an order as yet? I'm sure many of us would be interested to know of someone who has purchased "clone" STM32 chips from AliExpress for PCBWay to use on their boards AND be successful in having those boards operate correctly!

I'm waitin too )) Hope Tinkertilter will get his order soon and we will know ))

[Baz]

Hello 

When you order this pcb assembled does the kit contain the led panel as well or I have to buy it seperately for example aliexpress?

Thanks 

Baz

[ItemKiller]

1 hour ago, Baz said:

Hello 

When you order this pcb assembled does the kit contain the led panel as well or I have to buy it seperately for example aliexpress?

Thanks 

Baz

Order two pcs for each pcb. https://aliexpress.com/item/4000002686894.html

[reinkc]

I have a couple new EVO boards that load firmware fine, panels look great, but do not detect input signal from real pin. No blue light flashing. Other boards from same batch work fine on this same pin, and I tested these 2 boards on a different pin just to make sure. I have tested continuity and resistance from input pins (J2) to respective CPU pins, all look good. Is there something else I can check? Thanks in advance.

Edited December 8, 2021 by reinkc

[lucky1]

Check the circuit around the LS123 for bad solder joints or any difference in the voltages compared to the working boards.

[Tinkertilter]

On 11/25/2021 at 1:52 AM, OzStick said:

Have you gone ahead with such an order as yet? I'm sure many of us would be interested to know of someone who has purchased "clone" STM32 chips from AliExpress for PCBWay to use on their boards AND be successful in having those boards operate correctly!

 

sorry been swamped with work. boards arrived 2 days ago and chips had arrived before that, which was unfortunate as I am now dealing with the aftermath of possibly having bad chips and fighting Ali express for a refund....

 

I installed 1 chip successfully however, it won't detect on my windows computer, so I figured I would try a second one but I accidentally pulled a pad off the board when installing the STM - I was attempting a clean-up/repositioning and got ambitious and pulled too hard - It sucks, oh well... I am hoping the board can be stitched and or jumpered to replace the pads but not sure it can be, I can't figure out where those legs/pads lead too, as I do not know how to read the schematic very well yet, I need to understand the schematics a bit better, but I am learning still.

For now, I will assume I am down a board, ouch, regardless, please take a a look at 2 of the pictures that belong to this board ( you will see the pads pulled off) and tell me if I can stitch it somewhere and save it from the trash bin, I can easily stitch it under the microscope as I am good with that, lol, when I am not pulling pads off.

 

Going back to the one that is soldered properly, I checked the soldering on the microscope and seems really good, I used the test points on the board (I assume that is what those are for?) and I have continuity, however - as mentioned -  I am not savvy reading the schematics,  - yes I am a dare devi in doing this with my limited knowledge but this is how I learn, go easy on me :) -  I know and maybe a bit naive but here we are... To me this is a good experiment and a experience and I will make this work.

 

I did check the boards against the pictures posted here, and responded PCBWAY questions the best I could and I believe I  made sure the components are oriented properly BUT it is always a good idea to have another set of eyes, please I will need your help with that to discard any other issues, thank you.

 

Once I get confirmation that the boards are fine, I will wait for DigiKey or Mouser to have the STM in stock and install theirs instead, it might be a while but ordering from Ali does is a gamble I am willing to do only once..Not everything is lost, please give me a hand take a look at my boards and let me know if you think something is wrong, maybe there is something really obvious I have missed and maybe the chips I got from Ali are good after all.

 

Please take a quick look at my pics, I can upload better ones if need be but it has been a long day and this is the best I got now, running out of fuel, but before the day is over wanted to drop a line here asking for some ideas.

Thanks in advance.

 

Here goes nothing.

 

 

 

Edited December 9, 2021 by Tinkertilter

[reinkc]

4 hours ago, lucky1 said:

Check the circuit around the LS123 for bad solder joints or any difference in the voltages compared to the working boards.

 

I checked the following for continuity successfully:

IC1:1 - Grd

IC1:2 - SJ1:2 (facing bottom of board)

IC1:3 - C40(+) (I think it's the pos side, the other side faces ground)

IC1:8 - Grd

IC1:13 - SJ1:1

IC1:14 - C35(+) (again, not certain on polarity, I'm new to this stuff :-) )

IC1:15 - C35 & R20

Ic1:16 - U1:16

R20 - C41(+)

C41(-) - Grd

C40(-) - Grd

 

For voltages I wasn't certain what to check, here are some:

IC1:16 to Grd : 4.75v

IC1:2 to Grd : 1.68v

IC1:13 to Grd : 4.17v

R20(-) to Grd : 4.75v

R20(+) to Grd : .67v

[reinkc]

4 minutes ago, reinkc said:

 

I checked the following for continuity successfully:

IC1:1 - Grd

IC1:2 - SJ1:2 (facing bottom of board)

IC1:3 - C40(+) (I think it's the pos side, the other side faces ground)

IC1:8 - Grd

IC1:13 - SJ1:1

IC1:14 - C35(+) (again, not certain on polarity, I'm new to this stuff :-) )

IC1:15 - C35 & R20

Ic1:16 - U1:16

R20 - C41(+)

C41(-) - Grd

C40(-) - Grd

 

For voltages I wasn't certain what to check, here are some:

IC1:16 to Grd : 4.75v

IC1:2 to Grd : 1.68v

IC1:13 to Grd : 4.17v

R20(-) to Grd : 4.75v

R20(+) to Grd : .67v

 

Ok, seeing way too much voltage drop through R20. Shit.

[lucky1]

5 hours ago, Tinkertilter said:

I installed 1 chip successfully however, it won't detect on my windows computer

Did you set the chip into DFU mode by holding down the DFU button during powerup ?

If it is not in DFU mode and no firmware is installed it will not be detected by windows.

[lucky1]

7 hours ago, reinkc said:

For voltages I wasn't certain what to check

Simply check against a working board wether you can see any difference

[reinkc]

2 hours ago, lucky1 said:

Simply check against a working board wether you can see any difference

 

I did on a few, and R20 shows a 4v drop through it. I believe that is the culprit. I guess I'll order some of those and try to replace unless you know of a good workaround. It's a 1001. What happens if I remove it and solder bridge right there? I know it's probably a dumb question but I'm learning.

[Tinkertilter]

Thanks for the response, I push the dfu button only after the board is powered up and connected to usb , hold it and then press the other button, then release dfu (all after the board is powered up). 
is this incorrect?

 

should the dfu button be held before power up and usb connection? Maybe As follows:

 

1- press button

2- connect to power

3- connect to usb

??

 

Thanks

[lucky1]

1 hour ago, reinkc said:

I know it's probably a dumb question but I'm learning.

It is 😉 You can try to measure the resistance of it to see if it is correct.

[lucky1]

9 minutes ago, Tinkertilter said:

Thanks for the response, I push the dfu button only after the board is powered up and connected to usb , hold it and then press the other button, then release dfu (all after the board is powered up). 
is this incorrect?

 

should the dfu button be held before power up and usb connection? Maybe As follows:

 

1- press button

2- connect to power

3- connect to usb

??

 

Thanks

 

1. connect to USB

2. hold dfu button

3. connect to power

[reinkc]

1 hour ago, lucky1 said:

It is 😉 You can try to measure the resistance of it to see if it is correct.

 

I may be zeroing in on the issue.

 

Resistance between pins 14 and 15 on IC1 on the good boards = 1.6kΩ

 

Resistance between pins 14 and 15 on IC1 on the bad board = 3MΩ

 

Is this a clue? Could it be bad chip?

[lucky1]

10 minutes ago, reinkc said:

Is this a clue? Could it be bad chip?

 

It is ! I would change or resolder C35 as a start

[Tinkertilter]

- deleted / double post

Edited December 9, 2021 by Tinkertilter

[Tinkertilter]

3 hours ago, lucky1 said:

 

1. connect to USB

2. hold dfu button

3. connect to power

 

I did try this, and no prompts on the computer. I presume windows will pop a window up like when connecting a USB key, correct?
there is no indication of anything plugged in or prompts.

 

I did receive another order from a different seller, so I am tempted to try these chips, they claim to have 100% genuine chips so I feel like giving it a shot, the problem with this is that if it does not work, then, I will have to remove the chip and it is another step that puts the board at risk...

 

with that said, can someone tell me where can I stitch the first board that I damaged? please look at the pictures I posted earlier, you will see the pads pulled off. 

I tried locating the connection with my tester but I cannot find where it leads, if someone can guide me here I will appreciate it - or, I will keep the board for parts if need be.