Thanks liudr for your reply, Today i tried to buy 1n4004 diode but all verdors are saying that the replacement/upgrade is 1n4007 and 1n4004 is outdated and not avalable. Do you have any other solution for this problme? Thanks in advance.
All of the 1N4000 series devices are essentially the same except for their reverse voltage rating. The higher the number the higher the voltage rating. Therefore a 1N4007 can replace a 1N4004 with no problems.
Don