@Edward Huggins
I went back to your idea of measuring continuity on LH & RH Channel DIN connectors: -
Quote:
Originally Posted by Edward Huggins
The 5 pin DIN marked "Stereo" is not for speakers, but for recording and playback from a tape recorder. It's exteremely unusual to see 5 Pin DIN sockets ever used for speakers and I expect the other spare pins are used to connect the flashing lights arrangement and these may carry higher voltages. Double check the actual speaker LH- LH+, RH- RH+ pins on the rear of these sockets with a continuity tester before you hook up any standard 8 ohm speakers i.e. 2 wires to each speaker.
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I don't have a digital tester, I try to get by with an old-school analogue meter. But this should be adequate for this task....
But I don't really know what resistance to expect, or what I would learn from doing continuity checks?
I performed the following steps:
1) Powered up record player, with vinyl playing
2) Set my meter to Resistance x 1000 range
3) Measured resistance across Pins 1 & 2 on LH channel (Pin 1 being the one where I previously measured very little or no voltage, Pin2 clearly is ground from PCB)
4) Resistance reads 14 Ohms
5) Repeating process for Pins 1 & 2 on RH channel also gives 14 Ohms
6) Either Channel - 14 Ohm increases to 30 Ohms when record stops playing
7) Resistance between Pin 1 LH with Pin 1 RH reads 65 Ohms, although this increases to circa 500 Ohms if the record stops playing
8) As expected Pin 2 LH with Pin 2 RH measure zero Resistance (both wired together and go to ground)
On this basis, and noting both your (and Chris's) advice to avoid the higher voltage Pin3's, I wired a pair of 10W 8 Ohm TV speakers temporarily to the Deck (LH Pin1 to LH+ speaker input, LH Pin2 to LH- speaker input, RH Pin1 to RH+ speaker input and RH Pin2 to RH- speaker input).
No luck, no sound from speakers.
So perhaps there is a Main PCB fault somewhere...
Or the 16v Pin3s are used as + feed to speakers in some way, but use
resistor? circuitry inside the speaker box to downsize the voltage to a sensible level for speakers.
I'll try taking Main PCB out to inspect its upperside for any damage - but suspect I will need to schematics to solve this one.....