Has anyone here from North America with HW 1.2 SW 1.5 sent their unit back to China to be reflashed? How long did it take and how much was it?
I was really dumb and tried updating the firmware when I knew there were issues and I am beyond the 1 year warranty so SMSL wants me to send it back to their factory on my own dollar.
Hello
@Crohnic and all. Sorry for this late follow up but have been quite busy with assorted projects. We ended up purchasing a bricked SMSL M500 unit out of Australia and did manage to disassemble the unit for a review. Our unit was quite tight to remove the wedged stacked circuit boards but others have reported that the same pair of boards slid out fine. Perhaps just bad luck that almost needed soap to slide the boards out.
The 2 x flex ribbon cables are quite short and will be impossible to use again as supplied by the factory after the unit is disassembled. Others have reported the same concern - the ribbon cables must be replaced with a longer set.
We have studied the surface mount flash memory device which is a 8 pin SOIC package that is common to the industry. Initially thought to build a personal reflashing tool that the end user can clip onto the existing surface mount flash device. This piggy back tool is common in the electronics industry. This clip on + ground + another wire to force the circuit board into RESET mode (ie. RESET line = GROUND will allow for the onboard XMOS CPU to release the lines that are linked to the flash memory device). After this setup, the external flash programmer can erase / program & verify the new firmware. The same tool could be used to restore the flash memory anytime in the future..no more bricking.
Technically, the firmware is held inside a SPI flash memory device that is very common and from Winbond Semiconductor. Using the above setup, an external SPI bus master can come along and communicate with the SPI flash memory device to erase / program / verify the contents - just like the factory did. They performed the same task out-of-circuit and soldered in the ready to use flash memory during the pcb assembly process. We had hoped that some contacts / connectors would be exposed to quickly perform this hardware fix. None have been found.
However, believe the above is not practical since it may be a one-time use tool. While we can build such a device, it may not have much value and can be difficult to use with the spring clips + ground wire + RESET probe wire. Too many contacts to correct the firmware while the flash memory chip that is bricked onboard. There is also an AC to DC power supply which we wish to not have the end user be exposed to due to risk of a shock.
Plan B is what a number of other SMSL M500 owners have already done - believe they have been mainly in Europe and Russia. That is, to use a hot air tool to carefully desolder the same flash memory -> insert the flash memory device into an external programmer (about $20 on Amazon USA; about $10 USD on Aliexpress) -> reflash the contents -> solder the chip back. Rebuild the unit using longer flex cables as the original ones are far too short.
This method is confirmed to be working.
We have invested a number of hours to see if we can communicate with the box over the USB and what is left of the DFU interface and Windows programming. So far, no luck on this approach to fix the box. Ideally would have been the best solution. Still not done with this research but not looking very positive.
Plan C may be worth a consideration and that is for us to ship to you a kit of a pre-programmed surface mount device (2.06 firmware) + the longer flex cables. Then you can take your unit to a local cell phone repair shop - just ask in advance if they are confident to "remove a surface mount 8 pin SOIC device and replace with another" - estimating that the procedure to dismantle the unit and perform this task and put back together is 1-2 hours at most. You may even wish to carefully dismantle the unit yourself and bring in the stacked board to the shop and respectively, you can rebuild the unit after this operation. A quality cell phone / computer repair shop will find this to be a breeze to replace the single component. We perform low level repairs on macbooks / ipads, etc. daily on much much smaller components.
Plan D is to send the unit to us and we can do the same -> perform the above task and return back to you. We are in Windsor, Ontario so it may make sense to those who are nearby. Best solution is to apply the new smd flash device locally for the least downtime.
To readers who are outside of North America, you may want to consider to purchase the programmer tool that a few have done already. We can document this procedure but highly recommend that the removal and resoldering of the flash memory be handled by a qualified repair shop.
The firmware is encrypted and respectively took a bit to have the SMSL factory release the binary dump to us of the flash memory. In summary, the corrupt memory device needs to be erased -> programmed -> verified or replace with the same device but with the 2.06 firmware.
Moving forward, this issue should not surface again since you will be on the working firmware and the factory has stated that they will not have this quirk on future releases of the firmware.
Feel free to share your feedback and we can gather up more details on the unit and post here for public access. Need to review a fair cost to both parties for the kit and if you would like for us to perform this service. We do have very good ship rates from us in Canada to the USA with 2-day Fedex delivery but unfortunately not the same relationship for incoming parcels. Believe that all together, the costs have to be lower than shipping back to China.
Thanks.