Currently we did stop the idea to convert from T1 to E1
To give you an idea about the hopeless try to convert a MAX 4000 from T1 to E1, here are some of our documentation pictures :
T1(production after 1996 week 50) -- E1(production after 1995 week 49)
| The T1 unit always terminates all 4 WAN ports with 100 Ohm impedance. | The E1 ports offer 120 Ohm or 75 Ohm switchable WAN port termination with jumpers. We mostly use 120 Ohms in Germany. |
So the 8 line transformers (4 x in and 4 x out) must be replaced.
- seems to be the same on both units
- Both of these chips are in a socket, it is no problem to replace or exchange them.
| Here is the biggest problem, it is a special T1 chip, it must be replaced. | This is the new E1 chip, which definetively has the E1 specs inside the silicon chip |
- seems to be the same on both units
For you it is possible, to unsolder the MT8976 with a lot of luck, may be you kill some of the contacts or foils and you may be able to fix a few mistakes on one chip. But on more than one, you will get crazy. Furthermore you must buy the replacement parts and chips, it makes no sense to destroy another E1 model for these tests. And you must exchange the crystal too. Currently these old chips are available by accident only. You cannot plan anything.
We own all the PDF specifications of all chips, will be published in our PDF database shortly. At the end my tip - better forget it.