Update README.md: add a working imaxB6 schematic link

README.md

@@ -187,7 +187,7 @@ Useful materials
 - Cheali Charger V0.33m - User Guide: [English](https://docs.google.com/document/d/1Nv2vBXbWo6qE2U9rXZfzVDTfWu3j778flImbFJp74tk), [Hungarian](https://docs.google.com/file/d/0B1RXXTatsA1cWVJYbERUSWo5Q28)
 - balancer modification, Hungarian: [pdf](http://file.emiter.hu/file/Modellezes/Cheali/Tuning/HK_es_TURNIGY_TOLTO_BALANSZ_tuning_javitott.pdf), [website](http://rc-miskolc.emiter.hu/rc-miskolc/index.php?option=com_content&view=article&id=278&Itemid=205)
 - Gyuiri's schematics: [turnigy 2X400](https://drive.google.com/file/d/0B1RXXTatsA1cczlMR184LUVZSkE), [turnigy 2x200](https://drive.google.com/file/d/0B1RXXTatsA1cb1R5NHM3MEtsakE), [turnigy 8150](https://drive.google.com/file/d/0B1RXXTatsA1cbkM2dXFxTldjTUU)
-- [Imax B6 Schematic](http://www.rcgroups.com/forums/showatt.php?s=df7049bcbafdb5d7d06765c264e5c4bb&attachmentid=3693125&d=1293732709), [rcgroups](http://www.rcgroups.com/forums/showthread.php?t=1362933) 
+- [Imax B6 Schematic](docs/imaxB6/imax_b6_hobbyking_eco06_digital_charger.pdf) from: [rcgroups](https://www.rcgroups.com/forums/showthread.php?827821-iMax-B6-service-menu/page21) 
 - Panasonic [ni-mh-handbook-2014](http://eu.industrial.panasonic.com/sites/default/pidseu/files/downloads/files/ni-mh-handbook-2014_interactive.pdf), Duracell [Ni-MH_Rechargeable_Batteries_2007](http://www6.zetatalk.com/docs/Batteries/Chemistry/Duracell_Ni-MH_Rechargeable_Batteries_2007.pdf)
 - [batteryuniversity.com](http://batteryuniversity.com/)
 - Atmel [AVR463: Charging Nickel-Metal Hydride Batteries with ATAVRBC100](http://www.atmel.com/Images/doc8098.pdf)