when i connect left front speaker it's shuts down .
That is probably due to protection caused by either
DC or over current. This means your troubleshooting is not complete.
Preform these steps.
Download SR605 service manual.
(a)unplug the amp.
(b)Connect left speaker (c)remove the vertically installed pre-amp board.
How to do?
1.Unplug the amp.
2.Remove the metal cover.
3.You will see a long vertically installed pre-amp board mounted next to those large power transistors fixed by 12 screws on a large aluminium heat sink.
4.Remove this long vertically installed board mounted by 2 screws.
5.With 2 screws removed, just pulling this board out and hold it with one hand.
(d)Plug the amp and switch it on.
(e)If your amp stays ON forever, the problem is from this long board.
(f)If switch off at once, the problem is from power amp board.
Try the above- mentioned steps to confirm DC or over-
current in left channel.
(g)For DC protection, replace ALL components on left channel of the vertical board.
(h)For over-curremt protection, replace ALL components on left channel.
Replacing ALL components on a faulty channel do not cost you too much.