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Old May 31st 10, 08:19 AM posted to alt.collecting.juke-boxes
Rob in NYC[_2_]
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Posts: 103
Default Write in problem: Seeburg L-100

On May 30, 2:44*pm, Grojohn wrote:
Ok,

Just discovered something else. If I take the write-in line to a 18k
resistor then ground and manually engage the subtract solenoid, I get
10 vdc across the resistor. Again, if the circuit is open and engage
the subtract solenoid, I get 19 vdc.

Ok, so I hooked up another meter in series with that 18k resistor to
monitor the current draw. I get 10 vdc but only .5 mA. *I dont think I
have enough current to preform the write in.

John


John, I don't want to be pessimistic but measuring the W-I pulse
directly is likely to be misleading due to the fact that there are two
coils and caps in the circuit. The pulse has higher voltage "front"
and this was to overcome resistance that might build up in contacts in
the circuit that could cause erratic selecting.

You also need to use care with the tormat unit as I have bought
machines with some burnt out coils and they are bitch to fix.

I'm looking at a schematic of the w-i and after checking voltages
there are only a few resistors and caps plus one diode (never had
failure here). According to my notes the only problems aside from
contacts are the 120K , 3K and 47ohm res.

Resistors in high voltage pulse environments of break down in peculiar
way and it might be good to just change these three (if you haven't)
Other than that you may have a current leakage problem in either the
phenolic board, credit unit (often happens).

I have a simplified print of both w-i and r-o circuits that has been
all that I have ever needed get these going on location..the circuits
are really simple.....I'll scan/send if you want.

Lino
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