Lamp Replacement and V4 Module Driver Replacement

Change the lamps with power off.

Some newer lamps do not have enough solder on the base of the lamp (see Figure A). The base of the lamp should be rounded (see Figure B). When you place the lamp that does not have enough solder on it into the socket, it will cause the contacts in the socket to arc together through the base of the lamp (because the base of bulb is flat). The lamp will make contact with the Hot Tab and the Rivet holding the Neutral Tab (see Figure C). Once that happens ether the socket or the V4 Module Driver Board will fail. Because the traces on the V4 Module Driver are small, most of the time that trace will be the first to fail, however the socket could also fail.  If the socket failed , then at this point the socket will need to be repaired/replaced. If the V4 Module Driver Board is replace WITHOUT fixing (or replacing) the bad socket first, the V4 Module Board will most likely fail again (that trace on the V4 Module Driver board for that bulb location).


1. Mark all the bad lamps first. Do this for both sides.
2. Turn power off.
3. Remove bad lamps.
4. Pull up center tab on each of the sockets that the bad lamps were removed from.
5. Make sure the new lamp has enough solder on the base of it.
6. Put new lamps in.
Do the above steps 3 – 6 for both sides!!!!!!!!
7. Replace V4 module driver board (only if you are in need of replacement).
8. Turn power on.

NOTE: YOU MUST CHECK BOTH FACEs The lamps on Face A are tied to the lamps on Face B. Lamp on the top right of Face A is tied to the Lamp on the top right of Face B. If a socket is bad on one face, then it will cause an issue on the other face. YOU MUST CHECK BOTH FACEs before turning power back on.


Figure A

Figure B



Figure C



If power is on when changing the lamps, it could cause the lamps to be “stuck on” all the time or it will burn off the electronic trace on the module driver causing the lamps to always be off.


Lamp Sockets
Triboro 14572
Triboro 14573


Type of lamps used in some of the older signs
Ushio 1003215 30A15/F/20
Ushio 1003204 – 30W R-20/LF/20K