Write in problem: Seeburg L-100
 

I have a write in problem.

I have the manual, but the tests are for models 101,161, and 201. My
TEU board and RCSU1 board have the same test points, so I think the
tests are will work.

Ok, Test B works; Thats when i unplug the memory unit RCA jack, do a
scan and touch from test point C to the inside socket for the memory
unit on the TEU board. GOOD!

Next, test C works, the battery trick; GOOD!

Now it tells me to use test G to pinpoint.

Test G tells me to connect a test lamp from point D to A. This is
from the write in points(D) to ground (A).
My lamp does not glow and i make a selection and my lamp does not
glow, so it tells me to go to test J.

(my lamp is homemade; its a 28volt lamp with leads, and I tested it
with a 9 volt power supply and it did light)

Ok, onward to test J. I remove the jumper between test points D and E
and hook up my lamp. It does NOT show a dim glow. Its says it lamp
does NOT glow, replace "selection receiver (defective write in
electronics)".

SO, im guessing that my selection reciever is my TEU board.

Im getting good voltages -300 is about -298. The -150 is about -149,
and the -147 on the anode of the diode is there. The cathode to ground
measures 0 volts. Also, i pulled the diode and tested with meter and
it seems ok.

I have inspected and tested signals all the way up to the RCSU1. I
repaired the wiper contact on the SPU1.

I have also recapped the TEU board, but did not replace any tubes.

HELP!

John

Write in problem: Seeburg L-100
 

Grojohn wrote:
I have a write in problem.

I have the manual, but the tests are for models 101,161, and 201. My
TEU board and RCSU1 board have the same test points, so I think the
tests are will work.

Ok, Test B works; Thats when i unplug the memory unit RCA jack, do a
scan and touch from test point C to the inside socket for the memory
unit on the TEU board. GOOD!

Next, test C works, the battery trick; GOOD!

Now it tells me to use test G to pinpoint.

Test G tells me to connect a test lamp from point D to A. This is
from the write in points(D) to ground (A).
My lamp does not glow and i make a selection and my lamp does not
glow, so it tells me to go to test J.

(my lamp is homemade; its a 28volt lamp with leads, and I tested it
with a 9 volt power supply and it did light)

Ok, onward to test J. I remove the jumper between test points D and E
and hook up my lamp. It does NOT show a dim glow. Its says it lamp
does NOT glow, replace "selection receiver (defective write in
electronics)".

SO, im guessing that my selection reciever is my TEU board.

Im getting good voltages -300 is about -298. The -150 is about -149,
and the -147 on the anode of the diode is there. The cathode to ground
measures 0 volts. Also, i pulled the diode and tested with meter and
it seems ok.

I have inspected and tested signals all the way up to the RCSU1. I
repaired the wiper contact on the SPU1.

I have also recapped the TEU board, but did not replace any tubes.

HELP!

John






John, the main problem is you are not usingthe correct lamp. The Seeburg
Test Lamp is a specially chosen NEON lamp - not unlike the ones you can
pick up at your local hardware store - however they are selected for
thier voltage response. If I am not mistaken the standard Neon Glo-Lamp
test needs around 90 VAC to work, whereas Seeburg selected NEON lamps
that glowed around 80VAC. I could be wrong...

Still, using a regular Neon Glo-Test device will work for most
troubleshooting situations with the Seeburg test system.

http://commons.wikimedia.org/wiki/Fi..._Test_Lamp.jpg

John :-#)#

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Write in problem: Seeburg L-100
 

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

Write in problem: Seeburg L-100
 

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...

John :-#)#

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

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

Write in problem: Seeburg L-100
 

John, These models were notorious for edge connector problems (you've
heard this I'am sure).

From what I recall, this particular printed stepper requires that both
stepper wipers be at "home" position and making good contact with a
contact at that position in order to pass the write-in pulse from the
keyboard. The purpose of these contacts is to remove the pulse from
the keyboard while the stepper is receiving. The older and later
machines used contacts(which I eliminate) on a timing relay for this
purpose.

You should be able to test for stepper write-in by tapping out a set
of pulses by shorting the wallbox signal line to ground.

Also, IF this unit has a test link in the write-in circuit you should
be able to open it and with power off, connect your meter to the
contact that goes to the write-in contacts on both the stepper and
pricing unit. If there is no such link on your unit, connect to one
side of the write-in contacts (you'll have to try both) and the other
side to chassis ground.

Then with power still off, try pressing both a letter and number on
the keyboard and see what reading you get, you should use a meter
scale that can measure at least 5k-ohm because there are resistors
that will bring the to-ground reading to at least that amount.

The write-in goes first to numbers then to letters then to ground by
way of a 4 point 7k-ohm resistor. BTW: have you tested the resistors
in this section. If you have an assistant, have them hold down the
buttons while you jiggle the edge connectors at the stepper and tap
the stepper wipers and relays to check of any change in meter reading.

The printed boards on both stepper and tormat power unit
(TEU1)sometimes suffer from carbonization which bleeds away the write-
in current, I have had to eliminate the printed foils and do point-to-
point as well as eliminate the edge connector on these boards. You
have done voltage readings that appear OK so this is unlikely to be
the prob here.

I have had two L-100s and one K (200) the latter went into commercial
service and rather than dealing with the board problems which include
burning up, I modded that machine to use a 201 back door. Frankly,
although the L and K are favorites of mine they are a PIA to deal with.

Write in problem: Seeburg L-100
 

Update:

Seems like my circuit through the RCSU1 is ok.

I checked the resistance of all my resistors on the TEU board (pulled
one leg off), guess what;
there are about 16 of them out of tolerance...
I will up date in a few weeks after replacing these...

John

Write in problem: Seeburg L-100
 

I just discovered somemore info:

Ok, I had 18 vdc across the tormat memory. Using ohms law, I figured I
have 189.7mA
going into the selected toroid.


Question:
Does anyone know what current total is need to write in a toroid?

John

Write in problem: Seeburg L-100
 

Grojohn wrote:
I just discovered somemore info:

Ok, I had 18 vdc across the tormat memory. Using ohms law, I figured I
have 189.7mA
going into the selected toroid.


Question:
Does anyone know what current total is need to write in a toroid?

John


You measured this at the exact time you made a selection?

Write in problem: Seeburg L-100
 

You measured this at the exact time you made a selection?

I had to hold the subtract solenoid in on the credit unit to see the
voltage otherwise my meter would just flash too quick to see.

John

Write in problem: Seeburg L-100
 

Grojohn wrote:
You measured this at the exact time you made a selection?

I had to hold the subtract solenoid in on the credit unit to see the
voltage otherwise my meter would just flash too quick to see.

John

OK, that sounds feasible. You did have me wondering!

Write in problem: Seeburg L-100
 

Ok, still troubleshooting this write in problem.

The battery test works, it will read out perfect!

The wipe on the subtract solenoid works, when I hold it in I get
-19vdc on the write-in line.

I tried to eliminate the RCSU1 board by removing it, then using
jumpers to complete the circuit. Here is how i wired it:
http://home.comcast.net/~carniello/write.jpg. (this bypasses the
selection buttons but it is set-up like i selected number "3" and
letter "C".

By looking at the schematics and the write in circuit diagram, my
circuit should be correct.
I do have 19vdc from write in to ground, but only when the write-in
line is disconnected to Memory B3. When the circuit is together, I get
no voltage on the write-in line when wiper on subtract solenoid is
made.

Now Im starting to think there is not enough power coming from the TEU
board when the circuit is complete. Like I said, I'm taking the write-
in straight from the TEU board and using jumpers, the memory
connector, and a 18k resistor.

When the circuit is complete, no voltage
When circuit is not there, I get -19vdc from write-in to ground.

Reading voltages off the board are correct, -400 at pin 6 of 6x4, -147
at the diode, etc...
I also have that -19vdc on the cathode of the diode when the circuit
is NOT complete and wipe is made; otherside its 0vdc.

Help!

John

Write in problem: Seeburg L-100
 

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

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