Jim, It took me a while to figure out what you have. TLN5123B is not the model of the power supply; it is the part number of the Chassis and Hardware Kit in a TPN1110B Power Supply.
If your power supply blows the 10 ampere fuse F1 with no load connected to TB1 and both F2 and F3 pulled, you have greatly narrowed the possibilities. The most likely candidates, in order, are shorted CR1 or CR2, then shorted CR3 or CR4, and finally a shorted C1. If capacitor C1 is either open or shorted, the ferroresonant transformer cannot regulate properly. Note that more than 600 VAC appears across C1 during normal operation, and you must replace this capacitor with a similar unit designed for this application. 73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of kh6...@netscape.net Sent: Monday, February 23, 2009 8:36 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Motorola Micor Power Supply - TLN5123B I have a Micor power supply, that stopped working. I removed the power supply, currently no load on the bench. Back plane fuse - OK F3 - 13.8v fuse - OK, 0vac, Voltage 4.7vdc before F3 F2 - 9.6v fuse - OK, 0vac, Voltage 2.2vdc before F2 F1 10 amp. opens if left powered on. I am able to measure the above voltages before F1 opens. With no AC power, I measured the resistance across TB1, (After temporally shorting to ground to remove any stored voltage, and opening F2, & F3.), 15.3 ohms. There are not many components before F2, and F3. I guess the next components to check are CR1, CR2, CR3, CR4. Although, I have not seen many power supplies with C1 across one of the secondary, like Motorola P.S. It would be best to replace all four. Please send me your input, on the likely faulty component(s) to check. Thanks for your emails. 73's, Jim Kh6jkg.
