by Rob-NYC »
Thu Jul 26, 2012 8:55 am
"Would it be a simpler fix to find the proper gears to make it run 45 rpm?"
In a word: No.
Changing those gears -note plural is a pain in the ass. It involves major disassembly of the mech and removing some often stubborn roll pins.
I went through this in fall 1989 when i got in a "K" from the UK with 50hz gears. A year later when I needed a hideaway to run colsolettes in a diner, all I had was an HLPC I just rebuilt the speed unit.
There are so few components in that unit it makes no sense to go another route. In the case of floor models, making a radical change such as this can adversely affect the value of the machine (I should talk after what I have done to some of these circuits).
As for testing transistors, if your meter has a 'diode test" the testing of those common transistors is easy.
This is a case where testing with a hot chassis is the way to go -if you are comfortable with this approach. Start out checking that the relay engages when a record is clamped and then use the schematic.
If it does, check for around 25VDC on C2102 (1000mfd @30volt). Check the condition of the speed adjust pot. these are often a problem with dead spots or open windings. Check the diodes. If you have a capacitor function on your meter check the 4 mfd@370vac capacitor.
Do you have a schematic?
Rob/NYC
"If we believe absurdities, we shall commit atrocities" -- Voltaire