We have studied some problems of DLATR6.
This DLATR6 is an defferential Amplifier and a constant fraction discriminator. And this is optimized to be the I/O interface between the detector and the TDC (time to digital convertor).
Last week, we have found some problems of the DLATR6 that switching off the amplifier for MCP-back stopped all signals from outputs.
Therefore we checked circuit today, but no explicit problem were found. But when we tried to start again, we found signal from A1 was oscillating. This situation was found without bias high voltages, too.

The above graph shows A1 signal oscillating.

The above graph shows the difference between A3 and A4. Because of this reason, 2-dimensional image shape looks cut at upper side(y-direction).