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Old May 17th 10, 04:04 AM posted to alt.collecting.juke-boxes
Grojohn
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Posts: 19
Default Write in problem: Seeburg L-100

On May 16, 8:00*pm, John Robertson wrote:
Grojohn wrote:
Im wondering if a weak OA2 tube could cause my write in problem. One
of them does not glow very bright. I do not have a read problem as the
battery test works...


John


Well, a voltmeter check across the 0A2 should settle if it is good or
not. Should be 150VDC across each.

If OK, then check the 36 ohm write-in series resistor - I've replaced
lots of those over the years. It is located near the test strip - shows
up in the schematics - it opens up...


Got 150 vdc across each, 36 ohm is fine. Looking at the write in
circuits, it looks like the contact on the SPU1 shorts the write in
capacitor and write in trigger. I have confirmed this with a meter.
The write in ground also meters ok from the TEU to plug A1 on the
RCSU1.

Using my meter, from write in ground to write in, the reading is 0
vdc, but when a selection is made the it jumps up as seen on the bar
graph then back to 0 vdc.

My selection switches are ok as I have metered them also. I also tried
using jumpers on the RCSU1 to simulate the buttons being pressed.
I can load all the torriods manually with the battery, but is there a
way to load just one manually to verify the circuits in the tormat are
ok.

John
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