Quote:
Originally Posted by dieseljeep
The heater string is shown toward the bottom of the schematic.  |
Ok, will check it out.
OK So I figured out that you were right there were some micamold resistors in the radio, two of them in fact, one that was coded Red-Red-Black, which is 22 ohms which is the R32 you were referring to on the schematic, and just like you suspected, it was blown wide open (it measured infinite) but the capacitor was fine yet, which I suspect that maybe the capacitors were actually spared any damage from the reversed diode by that resistor and that R32 was actually where the magic smoke came from.
So If I understand you guys correctly I'll need to replace R32 the 22 Ohm 1 watt resistor with a 47 Ohm 2 watt resistor if I intend to use the 1N4007 Diode in place of the Selenium Rectifier? Also would R32 being blown open be the cause for a dead radio? If so It seems the repair may be fairly easy to get this radio up and running again, a lot easier than we thought at first.
EDIT: there are actually 4 Micamold Resistors in the radio, and 3 of the 4 Micamold resistors are measuring as open, the two 470 Ohm 2 Watt Resistors (R30 and R31) attached to the one 22 MFD 160 Volt electrolytic capacitors are both measuring as open when measured in Ohms, but when measuring in kOhms it measures as .475 kOhms, and then the 22 Ohm resistor (R32) measures open no matter how you measure it.
Then all but one of my filter caps measure normally, meaning that they are not destroyed, but the third filter cap, (the 22 MFD 160 Volt cap that R30 and R31 are attached to) measures 29 PF and that's all that shows up on the capacitor tester, I don't even get an ESR value from my ESR meter/Capacitor tester, so I don't know if that means that the capacitor is shot or if its because it has resistors in line with the capacitor and its affecting the reading or what the deal is.
I know that when I still had the original can capacitor hooked up yet and when I went to test the capacitor lead that those two 470 ohm 2 Watt resistors were attached to (the 20 MFD 150 Volt lead that was marked with the triangle), it measured the same exact way, and the other two leads measured as they were supposed (even with resistors attached to their leads).
What's really bizarre is that R30 and R31 when measured as resistors they don't measure anything (they measure as open) but when measured as capacitors they measure 29 pF (MMFD) which is strange because why would resistors be measuring as capacitors?
Also for some reason the filter cap that those 2 resistors are attached to is also measuring as 29 pF on my capacitor/ESR tester but it doesn't give an ESR Value for that filter cap, which its like the capacitor tester is testing that capacitor as a mica or ceramic disc capacitor rather than an electrolytic capacitor like it should be, which is weird because all of the other filter caps test like they should, and they have resistors attached to them.
Even more strange is that this same phenomenon I'm describing that's happening with R30 and R31 and C1B that they are attached to also happened with the original can capacitor when it was attached still before i changed out the old can cap for the new filter caps.
So I'm not sure what's going on here...
