Internet PLC Forum

General => Technical support => Topic started by: TTCSR on September 17, 2012, 04:13:41 AM

Title: FMD1616-10 repair?
Post by: TTCSR on September 17, 2012, 04:13:41 AM

A while ago an accident occured where something happend to an output and one of the sink driver chips ULN2803APG fried.  I swapped out the chip with a new one, however, now all the outputs 9-16 simply remain on.  

Is there anything I could change to fix them problem or is the PLC toast?

Title: Re:FMD1616-10 repair?
Post by: support on September 17, 2012, 08:06:43 AM

Output 9 to 16 on the FMD1616-10 are controlled by the chip TPIC6A595NE. If all these outputs are ON it means that this chip is likely damaged and need to be replaced. You can purchase this chip from Digikey.com.

Title: Re:FMD1616-10 repair?
Post by: TTCSR on October 11, 2012, 03:49:37 AM

Tried that, but the outputs still remain on.  Is there any other chip that I should try changing?

Title: Re:FMD1616-10 repair?
Post by: support on October 11, 2012, 10:04:09 AM

Try to replace the UU1 chip: 74HCT595. This chip controls output 1 to 4 as well as cascading the signal to TPIC6A595NE (output 9 to 16). So it is likely that what killed the ULN2803A also damaged the 74HCT595.