The triangle is recovery, so you are hitting the right combination of keys. But recovery is not finding the update.zip.
I have some of this documented in my TnT Lite original post, but a few tips (for TnT Lite):
- you have to make sure that you have the update.zip in the root of the drive, and then a recovery folder. So, for example -- if you are a Windows user and your GTablet is mounted to your F drive, you extract my ZIP or RAR so that you have a F:\update.zip and a F:\recovery\command file.
The command file is read by recovery and it tells recovery the name of the update file, and the location of the file. That's why you need both of these if you are using standard recovery (and, because you mentioned the triangle, I know you are using standard recovery).
This assumes you are using the internal device. If you are attempting a microSD card, it's a little different - again, read my first post on TnT Lite for details.
Android devices: ASUS Transformer, Notion Ink Adam, Cowon D3