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-   -   Write in problem: Seeburg L-100 (http://www.collectingbanter.com/showthread.php?t=291547)

Grojohn May 15th 10 05:46 PM

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






John Robertson May 15th 10 06:03 PM

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 :-#)#

--
(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."

Grojohn May 16th 10 10:39 PM

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

John Robertson May 17th 10 02:00 AM

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."

Grojohn May 17th 10 04:04 AM

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

Rob in NYC[_2_] May 17th 10 08:02 AM

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.

Grojohn May 19th 10 11:41 AM

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

Grojohn May 21st 10 12:32 AM

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


Tony[_4_] May 24th 10 01:36 AM

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?

Grojohn May 25th 10 12:42 AM

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


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