Model 39-55 Holding Relay Sticking Problem - Printable Version
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+--- Thread: Model 39-55 Holding Relay Sticking Problem (/showthread.php?tid=17622)
Model 39-55 Holding Relay Sticking Problem - Jotoole - 12-08-2017
Hi,
I am new to the Philco Phorum. I've pretty much finished the electrical restoration of my 39-55. It has one problem that I need to conquer before moving on to the cabinet. The holding relay often does not release after the stepper drive has completed operation. If I touch the actuator with the handle of a screwdriver it releases. I've lubricated under the assembly as best I can without removing the assembly from the chassis. There is an adjustment spring on each coil. the one on the holder relay is underneath the top coil in the picture below. Has anyone tried tweaking this adjustment to help the relay release?
Jaime
RE: Model 39-55 Holding Relay Sticking Problem - klondike98 - 12-08-2017
Welcome to the Phorum!
RE: Model 39-55 Holding Relay Sticking Problem - morzh - 12-08-2017
Are you sure that
1. There's no sticky substances?
2. The core is not permanently magnetized (is the relay ac or dc?) ?
3. No weak current for whatever reason keeps flowing through the coil when released?
RE: Model 39-55 Holding Relay Sticking Problem - Jotoole - 12-08-2017
Morzh,
No I'm not sure.
There could be sticky surfaces yet, but can't tell unless I remove the assembly which I was hoping to avoid. There could be residual current, though I don't think so. The 2A4G appears to be off and the capacitor should be fully discharged, since some times it doesn't release for quite awhile until I touch it. It seem to just be sticky surfaces. I would say thatit releases most of the time when selecting stations 3 to 8 and sticks most of the time after selecting volume changes or stations 1or 2. Before I removed the assembly I wanted to see if anyone had adjusted the spring tension first.
Jaime
RE: Model 39-55 Holding Relay Sticking Problem - morzh - 12-09-2017
It is open enough to degrease it with sone swabs and mineral spirits and then with undiluted isopropyl alcohol (you could use 90% from a drugstore but then blow-dry it).
RE: Model 39-55 Holding Relay Sticking Problem - Jotoole - 12-09-2017
Frustrating. I cleaned the mechanism and now its sticking worse. Cleaned it again and same thing. Its definitely dirty. I must have pushed some of the gunk in there good. I did check voltage across the coil and there is no holding current wen it is stuck. Its just needs a good cleaning. I've decided to take the assembly off so I can see what I am doing. I am not sure how to remove it. After removing the bolts holding it onto the chassis, do I remove the retaining clip on the top of the shaft and then pull the assembly up or do I remove the switch wiper (clock hands) under the chassis by removing the set screw and then pulling shaft and all up?
Thanks for the help. I will get there.
Jaime
RE: Model 39-55 Holding Relay Sticking Problem - morzh - 12-09-2017
I cannot tell you from here, but it looks simple enough, just watch spring for flying away and for retaining clips getting lost, and photograph or hand sketch the disassembly process.
RE: Model 39-55 Holding Relay Sticking Problem - 78zenithtv - 02-22-2018
Dont touch retaining clips yet! Just take out the 3 screws holding the unit to chassis and you willl see it lifts right off. the realys on top are connected to the rotary switch under the chassis by basically 2 levers engaging with each other. One has a slot and the other has a tab. The levers are between the chassis and bottom plate of the relay section on top(if you look between from the side on top you can see them). Just be careful as the one on chassis side is fiber board. You can remove whole unit without disassembly so you dont throw off parts alignment internal to relay section. See photos