Hi Folks, I'm trying to get a handle on what I have - as much to facilitate troubleshooting as anything else - and getting nothing but confusion... I have a P802M. controller board is listed as a Zonestar Melzi V3B questions: when I google Melzi there only seem to be v 1 and v 2 boards... what's the story there? is there a support resource and or schematics for the v3B board? Or is it really just a 2.0? firmware - there seems to be more than one firmware available - I'm assuming the firmware that came with the board is Repetier since that is the link that came with the board... does that help me? [reprap.org] I'm presuming I can pick and choose the firmware I want to use (and compile) within hardware limits - but how do I know what hw is applicable? At this stage I just want to get a handle on why the SD card reader has stopped mounting.... and consider my options to check it's state... so probably just a board layout/map is a good start https://reprap.org/forum/read.php?406,659971,659971#msg-659971 Tue, 16 Jun 2026 11:28:27 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?406,659971,660015#msg-660015 https://reprap.org/forum/read.php?406,659971,660015#msg-660015
I figured there would be something that identifies the hardware, beyond a name... glad (and bemused) that it's as simple as a single number...

now to solve my actual problem... (SD card seems to have stopped working)]]> bulwynkl Prusa i3 and variants Wed, 04 May 2016 03:36:11 -0400 https://reprap.org/forum/read.php?406,659971,659978#msg-659978 https://reprap.org/forum/read.php?406,659971,659978#msg-659978
First thing you need to do is identify the main cpu chip
most Melzi are atmega1284p or the older atmega644p, it will be written on the chip, but is in very small lettering

As for this board version, welcome to china marketing 101, if you increase the board number, you will get all the sales
And don't dare provide any documentation to help out those that buy your products....

There is a un official P802M support thread [forums.reprap.org]
And one nice user has setup [drive.google.com] with the original firmware

From here you can see its a motherboard 63, so its compatible with BOARD_MELZI in marlin for eg]]> Dust Prusa i3 and variants Wed, 04 May 2016 01:08:12 -0400 https://reprap.org/forum/read.php?406,659971,659971#msg-659971 https://reprap.org/forum/read.php?406,659971,659971#msg-659971
I'm trying to get a handle on what I have - as much to facilitate troubleshooting as anything else - and getting nothing but confusion...

I have a P802M.
controller board is listed as a Zonestar Melzi V3B

questions:

when I google Melzi there only seem to be v 1 and v 2 boards... what's the story there? is there a support resource and or schematics for the v3B board? Or is it really just a 2.0?

firmware - there seems to be more than one firmware available - I'm assuming the firmware that came with the board is Repetier since that is the link that came with the board... does that help me?
[reprap.org]

I'm presuming I can pick and choose the firmware I want to use (and compile) within hardware limits - but how do I know what hw is applicable?


At this stage I just want to get a handle on why the SD card reader has stopped mounting.... and consider my options to check it's state... so probably just a board layout/map is a good start]]> bulwynkl Prusa i3 and variants Wed, 04 May 2016 00:28:55 -0400