chassis problem

[8270king]

We had a thunderstorm pass thru a couple weeks ago and lane 13 wouldn't come on when we opened up. I changed the chassis and it fired right up. Last week I tried to repair the chassis and I am usually successful. But it is still down. When on a machine you can now turn it on and the machine will run for about 5 seconds and then it trips the master cb on the rear control box.
I have checked or repaired:
1. different omega tek board
2. different expander - old board and expander running in other chassis
3. f1,f2,f3 fuse and cb ok
4. replaced t-2 transformer
5. checked all ground wires
6. no c1 or c2 wires or terminals bad

feel free to jump in !

ex king

[Jimmy Jam]

Re: chassis problem

Try swopping the M relays.
Check for a grounded short( a c-1 or 2 term. that should'nt be grounded but meters to ground).
If it makes a sound like: BOING..1..2..3..4..BOING..1..2..3..4. then check for a loose screw/part grounding out the heat sink.
good luck, let us know what you find.

Re: chassis problem

87/20 king:

When you try and turn on this lane, do any of your motors hum? We had a constant blackout on lane 26 and it turned out that the cent switch was always engaging the start windings so it was drawing to much power and boom, tripped the breaker. I would hook up a multimeter to all motors ie: backend, combo's and see how many volts there drawing. Next thing is to get an amp meter and see how many amps your drawing but that is kinda technical.. good luck

deadwood

[Dutch]

Re: chassis problem

King,
Does it trip out if you have all of the motor switches off or the motors unplugged? How about if F1 is removed (Or disconnected, if it's a CB)?
Dutch

Re: chassis problem

King
i had something smellier happen it turns out that the mother board was the problem.
check out the wires that are soldered on to it one may be burnt.or loose
you may also wont to run a check on the mother board to see if its grounding out
good luck
Tim

Re: chassis problem

King,
Dont count your Chassis as scrap metal yet!
This Must be a Solid state Chassis for sure.
There is a 99% probability that the Diode under the "M" relay is Bad. Put your Multi meter across it and if it HAS Continuity its bad!!! Make sure you replace it in the same direction the arrow is pointing. The diode is polorized and will not work if soldered on backwards.
This diode is Small so look close. There is more than one in that area of the Chassis. Better be safe and Check all the diodes.
Let me know if this fixes the problem. Im sure one of these diodes is your problem.
Good Luck!!!

[GPS]

Re: chassis problem

Hey guys, as the King mentioned it is his low voltage circuit breaker tripping if I read his post right. Problrm will have to be in the control circuit part of his chassis and not the power section.

[8270king]

Re: chassis problem

thanks guys for the tips
i had to pull out 2 synthetic decks that were loose underneath
i will try to fix on 11/15

thanks
ex king

Re: chassis problem

Hey King,
Im sure its a Diode problem with the "M" relay.
You are correct GPS. The problem is on the Low voltage side. The "M" relay is 24 Volts
I have worked with solid state chassis with Omega-tek conversions for a long time. This Problem has happened in my center many times.

Reguards

[8270king]

Re: chassis problem

Alright here is what I have done.
I had alredy swapped both m relays to no avail. i took out my trouble light to probe all wiring and mother board connections - found nothing. On my chassis (ss) there are no diodes on the underside of the m relay plugs - there are diodes on the bottom of the capacitors.

When I plugged in the chassis today and found out that if I removed the f1 fuse the pit light would come on and would not trip the cb on the rear control box.

Also when I tried to power up the chassis with all the switches on in the control box the s contactor would spark - replaced the s contactor and checked all wiring and replaced most of the all of the wiring to the contactor.

How much would I get for scrap ?

p***ed off king

[Dutch]

Re: chassis problem

King,
Have you tried changing the heat sink assy? Here’s a long shot… Are any of the T2 terminals touching the bottom of the SWP relay?
Dutch

[Jimmy Jam]

Re: chassis problem

King, I think Amf Master meant the diode on the sp relay.

Re: chassis problem

King
here is a long shot but have you checked to see if the ( T-1 ) is grounding out on the heat sink. i have seen the bottom of them hit the top of the heat sink.

also can you narrow it down. when you turned it back on with out the F1 pit lite came on. did you try turning one switch on at a time?
first the table
then the sweep
and then the pit
and let us know what you find at what point did it trip the main. this could be a big help

[8270king]

Re: chassis problem

When iI turnes the machine on with f1 out the pit lite would come on but no motors would run. The cb would not trip with f1 out

grumpy king

[Jimmy Jam]

Re: chassis problem

With f1 out you are disconecting power to the t1 trans.. Thats all f1 protects. But t1 powers almost everything in the chassis so tracing down a short could take a while. If you have the red panic switch(c.i.s.) your c.b. will have 6 conections on the back. 2 for 24v manager control circuit, 2 for 120v c.i.s. circuit and 2 for -150v neon circuit. Old mach's have 4 they dont use c.i.s... So its not the c.i.s. tripping it. its not t2 tripping it. I would start at the t1 secondary circuits. Replace the diode under capasitor 3. Check cap3.
Some how power is getting in the t2 secondary circuit that supplies power to the s & t contactors. I'm asuming when you saw it spark you had f1 removed. You need to use the block diagram or schematic to find test points to meter t1's windings and see if its shorted inside or to ground. But start with that diode under cap3(they can meter good but be bad).

I might be leading you down the wrong path if I did'nt understand your post correctly so take heed.

You're lucky its not intermittent. You'll no when you got it fixed and how you fixed it.

jonas