jimstim defibrillation

[Russianblue]

i have a JimStim 1.3 that is pretty unresponsive.

I get a good 12v signal with my meter when measuring from the 12v post and ground post.
nothing on the 3.3v and 5v jumpers however. no lights other than the power LED.
nothing is getting remotely hot either.

so it appears that the 3.3 and 5v circuits are shot. the 12v circuit tests good all the way through to the terminal blocks.
i ran through the troubleshooting section but most of it was moot since nothing is coming through on the 3.3 or 5v lines.
in several of the measurements i would get a very weak 0.3v or something like that.

here is what else i did.

i took out the CPU, replaced D1 with a 1n4001 because it tested bad with my meter and i didn't have a 1n4004.
When i did this, i got a good reading on the 3.3v output.
still no 5v signal.

then i put my cpu in and powered up. now the 3.3v is dead again and D1 is testing bad once again.

i ordered a new CPU but am afraid to put it in because i don't want to zap it immediately.

any thoughts?

[BenGTT]

Hi,

5v is coming from your MS, not from the jimstim himself.

Ben

[Russianblue]

well, then it would follow naturally that my reading of 0v on the 5v line was correct ! you'll have to forgive me. i am a finance guy, mucking my way through this electrical circuit stuff. i find it fascinating but i am very ignorant.


okay, so I need to replace D1 again. is it possible that a bad CPU can kill D1?

[racingmini_mtl]

If D1 burns out then there is something seriously wrong but I'm not sure it is really bad. And a 1N4001 is fine.

The first thing to do is to remove the CPU and check the voltage at the CPU socket. The values are mentioned in the troubleshooting section. If you get the correct values then the issue is a bad CPU and putting a new one in will solve the issue.

Jean

[Russianblue]

thanks. i'll check that tonight and report back.