sundance-communications.com/forum Forums TDM Business Telephone Systems Comdial Telephones & Systems DX120 power supply

Looking to buy one. Had a DX120 go crazy spoke to tech support was told that the power supply was going bad. Phones would ring all the time displays are mixed up can not read them. I would power down two minutes power up and all is fine for couple of days

I never found one when I needed one. Had to replace the whole chassis. Everyone told me they are not available as a replacement part.

Why not just fix the existing PSU? The problem is likely bad capacitors.

-J

Check for 37vdc at the plug from the regulator board jz1 with the black and white wires. If that voltage is there and steady the problem is on the main 408 board. You can check them using the test points at the middle top of the board using the metal round ground point just below the voltage test points. Bad caps often damage 1 of the regulators and cause much bigger problems. So it might be best to send it in for repair if you see a problem with the voltages.

I can usually repair dx80 & 120 power supplies.
Contact me if you need a repair.

Has anyone tried using a third party power supply?? There are plenty of 36 volt hi capacity switching power supplies on the web.

The small board and transformer is only a ac to dc converter that creates the dc voltage that that are then regulated to 5 different dc voltages on the 4x8 pcb. This is where most of the problems usualy are.