DAMAGED SIMATIC CPU 314 by 230VAC

[Doggy]

Hello all,
I have to solve how to repair a damaged CPU314PNDP by 230VAC, which came to 24VDC power supply line.
Does anybody know, which components could be damaged on PCB
Unfortunately on PCB I see no sign of a damage.
Pictures are here for download: https://dl.dropboxusercontent.com/u/27536342/Photos.zip

Many thanks for any advice:doh2:

 

[Steve Bailey]

Don't bother trying to repair it yourself. Send it back to Siemens or an authorized repair shop.

 

[danw]

I lucked out once with a single loop PID controller that was 24Vdc. The factory installed MOV's on the power lines.

I stupidly plugged it into a chassis wired with 115Vac. BANG went the MOVs as they blew apart. Smoke came out of the cooling vents.

I replaced the MOVs and the unit is still running, 3 years later.

If it isn't as simple as blown MOVs or obvious damage to power supply, I doubt it's repairable. Schematic diagrams for industrial controls are typically not published for public consumption.

 

[Doggy]

I have asked an authorized service and they charge for repair about 50% of the original price. No matter what the failure is. For CPU314 it is 700$

Siemens does not need to accept this claim.

The fact is, that there is everything on one PCB.
No extra power board which could be easily replaced.

Thanks for Your hints.

 

[mk42]

In my experience, when you send a PLC in for repair, what you're usually doing is getting a module they had fixed previously (different serial number), and then they fix yours to give to someone else. You're essentially buying a used PLC, and using your currently broken one as a trade-in.

The fact is, that there is everything on one PCB.
No extra power board which could be easily replaced.

Out of curiosity, does anyone do this? Do any manufacturers make PLC/IO field repair easy?

I've seen some drives that have separate AC->DC and DC->AC modules, but they still aren't repar kits, just modules that can be replaced independently.

Maybe on the really large drives it makes sense? I don't have much experience there.

 

[boneless]

There is probably a PCB fuse on the board, look for a little square PCB component close to the plug. I recently repaired a 313C that went through the same experience.

I use the PLC for testing purposes only and am not recommending you do this for anything else then own use..

<edit: in the picture the component is the one marked OMF125>