9x upgrade to ATmega128A3-AU + Reboot With Horiz Trims

[zuadha]

can anyone give me a schematic (.sch will be prefer) the lower/bottom PCB only (both) that already mod to this (http://openrcforums.com/wiki/index.php/ ... Ground_Fix), due the PCB company on my country has a minimal size PCB order, i decide to build the bottom PCB too.

[Kilrah]

Nobody on here has a full schematic for the current version of the 9x.

[zuadha]

i mean just small piece trim PCB only, not the full schematic, and already has mod not the orginal. but i guess so, nobody on here has it

[Kilrah]

Nobody bothered making a schematic file as far as I know. But you've got photos in that thread that should show you everything you need to do it yourself of you want.

[jhsa]

What about the schematic from Gruvin? Isn't it similar?

Sent from my GT-I9195 using Tapatalk

[MikeB]

Doesn't have the trim switch circuits on it, just the connectors they plug into.

Mike.

[zuadha]

just like kilrah said,looks like i'll trace from my t9x, btw for bill version mod, that unnecessary to cut and move the orange wires, i read some issue

Just a quick note:
Having just done the modification:
It is unnecessary to cut and move the orange wires, if the cuts are made as shown for the left PCB top and bottom that's OK the orange wire analogue ground remains connected to the connectors that go to the pots and the switches are isolated ready for their connection to the digital ground. On the right PCB bottom side don't cut where shown but cut the trace between the switches and the trace running from the orange wire to the connectors that run to the outputs of the pots connector, at the edge of the pad on the switch, this maintains continuity to the analogue outputs, (make the bottom cut as shown), no need to cut or move the orange wire. Connect the digital wires as per instructions.

right bottom side.jpg

There is also confusion about left and right PCB's but take it that the right PCB is the one you see on your right when looking into the back, (but actually it's the left!)

Hi Bill,
I have just done this fix by Gruvin incorporating your suggestion. On finishing the mod, the left board's digital groung was totally isolated ready for the connection of the black wire (digital ground connection). However not so on the right goard. Digital ground was still connected to analogue ground. I traced this link to the copper strip on the topside of the right board between the connection blocks in a similar position as on the left board (Topside). I cut this (Thick) trace and the connection was gone. I can't remember seeing any reference to this trace in the posts so far. I could have missed something. That's very possible, grey cells are getting lazy of late. I'm all done and dusted, radio back together. Seems OK on switch on test (no smoke signals, yet). Good to go. Could you check and verify If AOK before I start using the beast in earnest and/ or mod my other radio ?. Both my radios have the same board layout.
Cheers.
Stan.

is that ok, have i missing something?

Yes in Gruvins text he wrote that you had to cut the thick piece on the front of right board but he didn't detail it like he did the other side.
It was kind of implied and I cut it like the board on the other side.
Perhaps the definitive Wiki by Mr Mbanzi should emphasise the right hand front cut as well as the left hand cut.
But rest assured you have done the right thing (pun intended)

[KAL]

I found some schematics of not only the mainboard in the infinite expanses of the internet
that seem to be based on gruvin's. I bundled them to one PDF with 4 pages.

Only PDF, but maybe they can help ...

[zuadha]

Vielen Dank KAL

[bob195558]

Here are some quotes from:
"Re: HobbyKing now offers 9x mainboards and LCDs as spare parts !" (viewtopic.php?f=42&t=6997)
about probable cause/s with the problems of Rebooting With Horiz Trims.

For the '128 chip, it is worth knowing whether the chip is actually a 128 or a 128A, and whether reboots happen. The '128A is a lower current (about half) version of the '128. Mike.

warning people that if they had a 9x with m64 that worked perfectly fine and replace their board with the new one they might suffer reboots!
And fixing the trim boards was one possible solution given the 9x mainboard as it was, but there would be ways to fix it on the mainboard as well that could have been incorportated in a redesign.

The voltage spikes that are caused by the bad design are exactly the kind of things that cause unpredictable behavior based on component tolerances. A cap that has a capacitance at the lower end of the usual +/-20% tolerance can cause a larger spike than one that's on the top end of it, a production batch of microcontrollers might be more sensitive to that kind of misuse than another etc...

Bob B.

[Quasimotoglez]

9xSchematics.pdf

(96.97 KiB) Downloaded 462 times

Nobody on here has a full schematic for the current version of the 9x.

see if this help

[ShowMaster]

I've been reading through the many posts act out reboots with H trims.
I never got to the point of upgrading to a m128 series could. The Skyboards were out three and I went that route at the time. Then the Taranis and HK 9XR Pro.
I did 6 9x conversions but never changed the M64.
The reboots seemed to be an issuer shortly after the m128 upgrade mods were becoming popular. The trim sw resistor mod as well.
My question is, was/is the trim sw mod required on the stock m64 boards? There hasn't been a complaint from the persons I did the original telemetry upgrades for, it's been maybe 2 years now, but I don't want them to have issues.

Should 2-3 yr old M64 boards have the trim resistor mod?
Did the telemetry Usbasp modifications make a difference reboot wise?

Will the new SP extreme board upgrade require the trim mod be done to a m64 board?

Anyone know if the HK 9X m128 board has the trim mod or will require it?

To be sure about the latest simplest trim mod, could someone post link to it? If I should look up these 9x owners I want to be positive I'm doing the latest trim mod. I'm hoping the resistor mod is the simplest and effective way to go. I really don't want to introduce trouble and just keep it simple for me.
Any crashes after I do any rework will be on my head. I'd rather leave it alone but they are good people and so am I.
Thanks
SM

[jhsa]

Any crashes after I do any rework will be on my head. I'd rather leave it alone but they are good people and so am I.

You definitely are good people SM

Here is the link for the trims mod.

http://openrcforums.com/wiki/index.php/ ... Ground_Fix

João

[MikeB]

I don't think we have had anyone reporting a reboot on the M64.
I don't think the 'spare part' M128 boards are any different to the original board. I did tell HK they could have a problem with them!
The 9Xtreme won't need any mods for the trims.

Mike.

[bob195558]

Yes a member of my RC group did have one of the 9x Radio with the M64 CPU rebooting problem
and after doing the Bill Trim Fix this problem was no more (it was fixed).
So I do the Bill Trim Fix to all (five) 9x radios so to make sure this problem will not think of happening in the first place (reliability).
Also see here for the Bill Trim Fix: (viewtopic.php?f=95&t=3594&start=120#p69475).

Bob B.

[ShowMaster]

I'll read up on the mod in case I do get a call. Thanks everyone for the links.

[ShowMaster]

I don't think we have had anyone reporting a reboot on the M64.
I don't think the 'spare part' M128 boards are any different to the original board. I did tell HK they could have a problem with them!
The 9Xtreme won't need any mods for the trims.

Mike.

Thanks Mike, good to know. I only found one 9x case that was modified to take a rotary encoder. There was a new unused encoder with it I assume I'll have to use if possible since the case was modified for it.

[JEANALTAYR]

Hello
Thank you all for your work I tried to understand and simplify
Here is the result
Jmi
Hope this help