Trace Repair on a Flex Cable DMD (Cherry)
Below are pictures that show various steps in the process.
A digital picture taken during display diagnostics makes it easy to count the columns to identify the bad ones.
Count the traces in the flex cable to find the bad one(s). In this case it’s columns 117 & 118.
CAREFULLY cut between traces to separate the broken ones.
CAREFULLY remove the broken traces. Scrape the remaining adhesive off with a toothpick (not shown here).
Melt a small blob of solder onto the iron tip and heat the contact pad on the DMD glass to tin it. Tin the end of a small piece of wire. Lay the wire on the pad and heat it to make a connection.
Wrap wire around and solder to printed circuit board. Note that I ended up replacing an additional column trace due to melting the edge with the soldering iron.
This picture shows a different DMD where I could wrap the rework wires around the board and solder directly to the column series resistor. Add a filet of solder to the resistor lead. Heat and insert the 1/8” end of wire to complete the connection to the resistor lead.
File: DMD Repair.doc Last modified: October 15, 2009