Rob
I purchased an R2i stuck on the bootscreen to try and learn about these sets. We had a faulty one ourselves (different, easier fault).
I found the Gyro 1128 module controlled the whole set and was at fault, but Gyro Signal who make the module have vanished. I found a brief datasheet for the module and began to realise it had a customised OEM interface, hence the label the screen. I removed the screen from the module and wondered whether the MX25L1605D flash RAM was responsible.
Then Google found your excellent post describing this fault. The genius thinking was to erase the tuning data. I was not brave enough to take another working set apart to copy the ROM.
So what I did -
1. Ordered more MX25L1605D flash roms.
2. Found the lastest Bullseye 64-bit operating system for Raspberry PI had Flashrom already installed - all that had to be done was to enable the SPI interface on the header.
3. I successfully read a new blank MX25L1605D and saved the blank image for later unexpected use.
4. I realised the required pins to program the flashrom appeared underneath the Gyro 1128 as follows:
TP1 SS -> pin 1 of flash chip
TP2 MISO -> pin 2 of flash chip
TP3 MOSI -> pin 5 of flash chip
TP4 CLK -> pin 6 of flash chip
TP5 reset -> pin 21 of the Gyro 1128 header (later used as a ground for programming as is it active low)
5. I took a brass rubbing of the underneath of the Gyro 1128 and pin pointed the above test points which I transferred to a PCB shown in the attached photos. The PCB was cut to precisely fit between the motherboard header connectors as photo attached. I purchased some spring connectors and made a complete jig. Simple concept - but the accuracy was hard.
6 Here is perhaps the best bit! The reset/header pin 21 is not used by the R2i motherboard and it is active low. I grounded header pin 21 by connecting it to the outer body of the RF input outer as per photo. TP5/reset is also now the ground connection for the purpose of connecting a programmer and I ALWAYS check TP5 is shown as grounded at the programmer before powering. Switching on the R2i with the reset to ground short did not even show the boot up screen - good. And even better all the required pins on the flash rom were high impedance when checked - excellent.
7. To be extra safe, Vita Audio R2i was powered by batteries for programming. I downloaded the faulty ROM for later examination.
8. I sent the command:
flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=2000 -c MX25L1605D/MX25L1608D/MX25L1673E --layout lay --image tuningda -w blank.hex
This updates/resets only the tuning data without touching anything else.
9. It worked. First there was a full scan and I think it unusually said 'Services N/A' when finished. FM was working. I went back to DAB and it did another full scan - all working this time. I did a factory reset afterwards.
10. I purchased a TIBO 161-DAB50-000 BOARD DAB MAIN BOARD/DAB TUNNER PCB REPLACEMENT because it had a Gyro 1128. Unfortunately the flash rom was faulty and would not read. I replaced the ROM with a new one and tried both Rob's images above to program it. Both images worked showing either Ruark or Vita on the boot screen. That was the only difference I could see.
And so that leaves the question what was wrong. I cannot fault anyone for replacing the flash rom. That is the logical answer and quicker than building this jig. But when I looked at the tuning data of the faulty ROM (attached for info only) there are large patterns of numbers spread over the tuning data suggesting the system may have crashed. Was it the flash rom or a power glitch? - I don't know but the set is still working months later with a lot of use.
I hope you found the above interesting and I was certainly thrilled to see the set working again and now have a spare DAB module with thanks.
Peter