Got a used GD77. Firmware upgraded. Broke the bootloader. Doesn't work anymore. Help

[W1ABQ]

So I haven't been active on air for years and decided I would get into dmr and get back on the air. Bought a used GD77 on ebay. And first thing I did was look for latest firmware and upgrade which it didn't do. Then I factory reset and tried to flash again. No more bootloader.....

Ordered a Jlink and plan to reflash modified bootloader in order to fix. Anyone have any pics or even video on how to do so? Never jtaged anything before and really just want my radio working.

Thanks

[VK3KYY]

I don't think anyone has done a video about this.

There is a thread on the forum about how to replace the bootloader etc, but I don't have a link to it.