Gauntlet monitor not being fed power from transformer

mulch

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Gauntlet monitor not being fed power from transformer

yes this may well be a transformer issue...

interested parties can read my ramblings on the machine as a whole here...
http://forums.arcade-museum.com/showthread.php?t=99093&highlight=gauntlet

this thread has kind of dried up though (i suppose my posts were getting pretty un-clear!) so Ive decided to do much more research...

However, one thing is for certain... there doesnt appear to be any power coming from the terminal on the transformer chassis up to the monitor... (i dont know how to properly test a transformer)

However, the game pcb IS receiving power (the red led lights up)...

Does anyone know what voltage the monitor is expecting?? as I am planning to feed it voltage from another source..

Any advice or warnings on this appreciated....

mulch 8)

gauntlet_6_MonitorRear.jpg
 
d'oh....

should have put a different title!!!

perhaps something like

HOW MUCH VOLTAGE SHOULD I FEED THIS MONITOR??

any ideas???

m 8)
 
I'm going to guess and say 120v. :) It is probably just using the transformer as an isolation transformer. In the picture, it looks like the power cord is unplugged, I am assuming that was only for the pic?

There is possibility a fuse in-line for the monitor somewhere near the transformer, have you checked for one? I don't have a Gauntlet (silently sobbing) so I have not worked on one before. Bust out the schematics and look at the wiring diagram. You should easily be able to follow the power into the game to the monitor so you can find that fuse, et.

-VJ
 
Hey VJ... nice one...

well remember that I am in UK so standard to transformer is 240v/250v -ish

I dont know if that affects your ideas about 120v

Regarding the plug... IT DOESNT HAVE ANYWHERE OBVIOUS TO GO!!????

Please advise if you know where it should go.... I have looked quite hard and found no obvious terminals for it to marry up with.... I had assumed that was a wire which enabled an engineer to see the setup screen if the main monitor was not working....

mulch
 
The monitor should run with no problems with voltages from 100 -130 but the norm is 115-120vac. Check that a.c. voltage first, if no voltage then check your isolation transformer input and then output voltage (a plug is off ?)and then work your way back to the fuse.
 
Well, that's a Hantarex monitor. Can you post a bigger pic showing a close up of the front left corner of the board, and the connectors there?

BTW - you should get a voltage reading there at one of those connectors of 200-240, I would think, unless there is a step-down transformer in the cab to convert the voltage down to 100-120 for the monitor...
 
ok... i am sourcing images... back very soon with those....

...in the meantime, remember that i am getting no readings from these wires because there is no readings present at the terminal from the transformer chassis (which i assume is the step-down transformer you mention)

Here is a view of the back of cabinet - transformer chassis at base of cabinet (i know its low resolution - will get better ones soon)

gauntlet_5_Back.jpg




Here is the underside of the transformer chassis... (all in good condition, all fuses are on the top side of this chassis and they have continuity - unless the 'filter unit' is a fuse?? - me still learning!!)

gauntlet_6_BeneathTransformerPlate.jpg
 
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The monitor should run with no problems with voltages from 100 -130 but the norm is 115-120vac. Check that a.c. voltage first, if no voltage then check your isolation transformer input and then output voltage (a plug is off ?)and then work your way back to the fuse.

isolation?? do you refer to isolating each wire and testing (ive done that for wires going IN)?? or is it an isolation unit of which you speak???

240v is definitely going IN to the transformer.....

maybe a plug is indeed 'off'.... but there are so few exposed wire to check under the chassis that im not sure of what to probe....

One thing that comes to mind is the jumper blocks which appear on the following picture..... Excuse the dust here - i have since cleaned and will take new photos... Here you see the fuse array and they all check out fine.... top left of pic is the terminal which goes up to monitor (well, the black and white wires from here do) and these 'jumper blocks' for want of a better description, seem fine except the one at the bottom of pic has three possible combinations of being plugged in (has 3 rows of 3 pins on the jumper block and only 1 row of 3 pins on the receiving terminal block on the chassis).... arg... i hope im making sense!!
gauntlet_2_FusePlate.jpg
 
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okay, that is an Atari power brick. Believe it or not, the monitor power will come out of that transformer with the Big Blue capacitor, the five fuses mounted on top, and the bridge rectifier missing, so they have nothing to do with the monitor power.

The only thing you need in order to get power to the monitor is:

1) Power input
2) Main line fuse in the black circular fuse holder
3) Voltage selector plug (for 120/200/240/etc)
4) power switch connector and working power/interlock switches
5) The far back left plug connected

That's it. If you look at that far back left plug, you measure the AC voltage for the monitor between the far back left pin and the far right pin one position up from the back right pin. Looking at it the way it is mounted in the cab, this crappy illustration below will show you where to put your leads (just in case you've been measuring wrong). Lead go in the X's:

XOO
OOX
OOO
OOO
OOO

Now, I remember when I was trying to get a 120vac Atari power brick here in the US to output 220 so I could test a european-meant monitor. I'll see if I can find it, as I had to do an additional jumper when test in order to get the proper voltage...
 
After looking at your pic of the brick, you'll have to figure out which two I meant based on how the connector was rotated....
 
Is the fuse inside the black fuse holder the one for the monitor on the Atari block? Or is that for the mains coming into the game and monitor fuse is on that main fuse block.
 
1) Power input
2) Main line fuse in the black circular fuse holder
3) Voltage selector plug (for 120/200/240/etc)
4) power switch connector and working power/interlock switches
5) The far back left plug connected

so many thanks.... ....

1 - Power Input - YES
2 - Main Line Fuse - YES
3 - Hmmm... not sure where the selector plug or even WHAT it is
4 - as 3
5 - seems fine to me... i spose i could do some continuity checks but like i said there is almost no bare wire to probe beyond that point...

THANKYOU so much though... it has re-energised me to take it apart a bit more thoroughly and properly trace that power line....

more pics to come....

PS - i now have the schematics AND an 'electronics for dummies' book!!! sounds crap but its actually very thorough.....

mulch 8)
 
3 - Hmmm... not sure where the selector plug or even WHAT it is
4 - as 3
5 - seems fine to me... i spose i could do some continuity checks but like i said there is almost no bare wire to probe beyond that point...

You have those connected. they are the 9-pin and 6-pin connector on your power brick.

As for checking you power output for the monitor, just pull that 15-pin connector out and measure it there at the socket attached to your power brick. If you get half of what you expect, or nothing, try measuring between and X and J in this chart:

XOJ
JOX
OOO
OOO
OOO

If you get about half what you expect, then you can stick a jumper between the J's and then the X's should now read the proper monitor voltage.

Here's my thread about how I got an Atari power brick to run 220vac out with a 120vac input - although I put the 120vac on the output pins so I could get 220vac on the input pins. Perhaps it will help you figure yours out. The relevant info is in the last post...

http://forums.arcade-museum.com/showthread.php?p=753176
 
As for checking you power output for the monitor, just pull that 15-pin connector out and measure it there at the socket attached to your power brick. If you get half of what you expect, or nothing, try measuring between and X and J in this chart:

XOJ
JOX
OOO
OOO
OOO

If you get about half what you expect, then you can stick a jumper between the J's and then the X's should now read the proper monitor voltage.
[/URL]

hmmm.... it seems to me that everything on my block is already wired exactly as your link suggests... but when I checked the two pins (X + X), i get nothing.... hmmm thinking about it though, i DID set the multimeter to DC... expecting only about 20v going up to monitor!!!!! (eeek!!)... So if i set multimeter to AC to check, should i plug it into the 10amp fuse port just in case?? I am assuming that if there WERE power coming from monitor pins, the multimeter would have registered SOMETHING?? perhaps i need to go back to that stage and measure using AC!!??

(just as an added reminder - i am getting 240v into transformer already as im in UK!!!!)

lets have a better look at my situation.....
here is the now cleaned transformer chassis from above...
I removed the jumper block (see below for close up of the removed jumper block)..
Notice the slight melting of the terminal socket... eeek... there is, however, NO melting on the terminal plug!!
GauntletChassisClean.jpg


Here is a close up of the 15pin terminal plug...
I am pretty sure (I will triple check) it is already wired up as you stated - with the jumper in place as you have put it on your lil diagram... and No.. i DONT know what that lil orange wire is up to!! (check my other thread linked in my first post to see my documentation of other wires that seem to have been snipped)
GauntletPowerTerminalPlug.jpg


Now, when I first looked in the cab, these two jumper blocks were cable-tied together... the one with lighter brown wires was unplugged entirely...
From checking your interesting and illuminating post about monitor power re-wiring, I deduce that the block shown to the right (which has lighter brown wires) is the one that ensures 110v and the one to the left (which has darker brown wires) (which was already in position on the board mounted terminal socket) ensures 240v or thereabouts. more logging to come... must sleep!!!

GauntletPowerJumperBlocksCloseUp.jpg
 
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Check the voltage on the outside pins of the connector indicated in the pic below. That is the voltage for your marquee light. If there is no voltage there, then the problem is in your line filter, line fuse, power switch, interlock switch, or the wiring between them....

GauntletChassisClean.jpg
 
Check the voltage on the outside pins of the connector indicated in the pic below. That is the voltage for your marquee light. If there is no voltage there, then the problem is in your line filter, line fuse, power switch, interlock switch, or the wiring between them....

OK!!!!

getting 117.5v AC there!!! is that correct??

m 8)
 
Here is a close up of the 15pin terminal plug...
I am pretty sure (I will triple check) it is already wired up as you stated - with the jumper in place as you have put it on your lil diagram... and No.. i DONT know what that lil orange wire is up to!! (check my other thread linked in my first post to see my documentation of other wires that seem to have been snipped)
GauntletPowerTerminalPlug.jpg

ok.... So i have checked the terminal socket again (the socket that the plug shown above slots into).... this time with AC setting on multimeter... (learning so much here!!!)

RIGHT!!! i get next to nothing (1-2v) when probing the monitor socket pins... when I probe the following socket pins (x) (1st is where the black monitor wire connects and 2nd is the opposite jumper pin) I GET 60v...

xox
ooo
ooo
ooo
ooo

I get nothing from any other monitor/jumper combination.... (i havent checked any other pin here)...

m 8)
 
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i guess the silence means 'check the schematics mulch!'

ok... tonight...

but any help would be great on the voltage issues there!!! check previous two posts for measurements I took...

m 8)
 
Post a bigger pic of the underside of your power brick and I will check the wiring (later tonight) to see if I can figure out where the power is being lost...
 
ok here is the underside in several photos.. over two posts!!!

hope you can help modessitt!!! Thanks so far... im crossing my fingers at this point!!!


1 - bottom left... under the terminal that send power up to monitor (and others)
GauntletPowerBlockBotLeft.jpg





2 - bottom middle
GauntletPowerBlockBotMid.jpg





3 - right side
GauntletPowerBlockRight.jpg
 
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