From time to time I must repair an equipment that has its own BIOS, CPU and SDRAM
This SDRAM has 256MB together and consists of 4 SDRAM modules(IC).
Sometimes equipment does not work.Then there are several possibilities for that.
Faulty CPU or BIOS or SDRAM.
Is there a method how I can find out that SDRAM is faulty? If so which module of those 4 SDRAM modules might be faulty?
Each SDRAM module has 66-pin Plastic TSOP(II) and is soldered on PCB.
Thank you for help

 

How about booting a memtest cd and checking the RAM for errors?

 

It is not a PC. It is a linux embeded equipment.It either starts, or NOT. No possibility to boot up in a different way but from BIOS chip only

 

It is not a PC. It is a linux embeded equipment.It either starts, or NOT. No possibility to boot up in a different way but from BIOS chip only

Well then i think you would have to desolder each and test it, which could prove quite problematic. Also, as it is SDRAMs, which need refreshing every few μs, you might be better off either changing them all if you can get them or getting a new box rather than testing them separately.