If you have lost the seed, there may be a way to retrieve your coins if there are a lot of them making this worthwhile to do, and your firmware version is an older version, this guy got his coins back that way:
https://www.wired.com/story/i-forgot-my-pin-an-epic-tale-of-losing-dollar30000-in-bitcoin/If the firmware is below 1.5.2, that will help you.
DO NOT RESTORE/ERASE IT WITHOUT THE SEED, DO NOT UPDATE the firmware, and if its below firmware 1.5.2, contact the writer of that article to get some help with it, as they are most likely retrievable via an exploit which pulls the private keys from the trezors RAM, IF:
1.if you have forgotten the pin,
2.lost the seed,
3. the firmware is below 1.5.2,
4. you have physical possession of the wallet.
5. Seed Passphrase protection is disabled
All 4 of these mean your trezor is exploitable to give up its seed via an exploit. If this is the case, then contact the writer of that article who could put you in touch with the guy who helped him do it, for a bounty he would probably help you.
I have studied this exploit HEAVILY, and it is a valid working exploit, but you only get one shot at it, as it wipes the trezor while preserving its RAM with a custom exploited firmware being flashed, yes before firmware 1.5.2 it loads its master seed into RAM, unencrypted.
If you have the seed, you can restore it to trezor, to a ledger wallet which i prefer to trezor, or into electrum to access your funds, but this is not as secure as using a hardware wallet! The seed means you need not go through this rigmarole.
This is the only way you will get your coins back without the seed or getting the wallet to open, and if the firmware is 1.5.2 or higher, the coins are gone im afraid, you must store the seeds so carefully.
The above is why I use ledger over trezor/keepkey, due to the secure enclave, but if it helps you get lost coins back, you might as well use it. This is not FUD or a scam post, its a genuine exploit, the wired writer there has a video of him recovering $30k of coins with it.
Barring this, find your written master seed, or remember the PIN/get the wallet open, and never store all your fortune in a single wallet. You can import the seed into electrum, checking the BIP option checkbox, this will not be as secure mind as its now on your PC, but will give you access to your funds if you need it if the trezor is defective, but move them to another hardware/paper wallet with multiple copies, pronto.
