HELP! - Replacing Voltage Regulator IC and Main Filter Capacitor.

[Wyluli]

I have a WG K7000 monitor.

[Ken Layton]

You are correct on both counts as to location of those parts!

The k7000 series had used 4 different voltage regulators in the production run so be sure to replace the unit with the same part number as what's in it now. Here are the 4 possibilities:

STR30130
STR3130
STR30123
STR3123

Bob Roberts stocks these.

[menace]

take a look in the faq--i put up readings from a known working str30130--compare yours to that and you'll know whether yours is pooched. 

[Wyluli]

Will do, thanks menace.  Do I need to worry about any kind of shock when I go to replace the voltage regulator? Is there anything special I need to do before removing it and replacing it with a new one?

I'm trying to read up on monitor info, but it's hard to find good sites and Randy Fromms is currently down, although I'm sifting through what I can in his index.

[Wyluli]

*ordered the parts and they are on the way. 
Anyone give me advice on this?  Do I need to worry about any kind of shock when I go to replace the voltage regulator? Is there anything special I need to do before removing it and replacing it with a new one?

[dabone]

"Is there anything special I need to do before removing it and replacing it with a new one?"



Yeah, unplug the monitor, and discharge the anode wire before you take it loose.

 

Once you have unplugged it and discharged it , there should be no more harmful voltage on the pcb. (But watch out for that tube, remember to discharge it again before you hook up the anode wire)

BTW, this is not the case for all monitors.. Esp a G07 with a blown fuse.
That one will remind you of how much a cap can hold.

Later,
dabone

[Ken Layton]

The regulator IC will have a thin mica insulator between it and the aluminum frame. Don't forget to smear a thin film of silicone heat sink grease on the insulator and the rear of the replacement regulator IC.

[Wyluli]

What is the best way to discharge the main capacitor?
What specific tool(s) should I use?


Summary:
Cap kit done.  Had to discharge monitor, remove pcb and neckboard.  De-solder old capacitors one at a time, solder on new capacitors one at a time making sure polarity is correct.  Tested monitor, works but still has wavy lines.

2. (NEXT thing to try) - To install Voltage regulator - Will need to remove pcb to do this so you need to discharge monitor, remove pcb and neckboard.  Unscrew and remove old voltage regulator.  Smear a thin film of silicone heat sink grease on the insulator and the rear of the replacement regulator IC.  Install new Voltage regulator.

3. (NEXT thing to try after #2) - To install Main capacitor - Will need to remove pcb to do this so you need to discharge monitor, remove pcb and neckboard.   MUST discharge the main capacitor before removing!  After capacitor is discharged you can then de-solder and install new capacitor.

[Ken Layton]

With the power off and assuming the circuit board is right in front of you here's how to discharge the main filter capacitor:

Use a screwdriver or pliers (with insulted handles!) and short across both capacitor terminals together. There might be a snap or arc sound or their might not be. Anyway merely touching the capacitor's two terminals together discharges it.

By the way, be careful when unsoldering the old voltage regulator. The copper foil traces on the circuit board are very delicate in that area.

[Wyluli]

I replaced the voltage regulator, but now my monitor will not turn on.

[menace]

ken will correct me if i'm wrong but I thought the mica is there to insulate the voltage regulator from the frame--heat gets through but electricity does not? If that is in fact the case then you likley pooched it. if not then you'll have to start checking things using the good ol flow chart i sent you.

[Wyluli]

ken will correct me if i'm wrong but I thought the mica is there to insulate the voltage regulator from the frame--heat gets through but electricity does not? If that is in fact the case then you likley pooched it. if not then you'll have to start checking things using the good ol flow chart i sent you.

So I probably killed the regulator?  Or is it possible I killed the whole darn board?   

[menace]

hard to say--maybe you should pull the regulator and test it first.

[Wyluli]

Thanks for the flowchart.

Do I have to disconnect the regulator from the board before testing it?
What do I set the multimeter to?
What points do I place the black and red wire on?

Sorry, I have never used a multimeter before. 

[menace]

yes you have to disconnect it first--I posted the info in the FAQ about halfway down--its pretty easy if you have a digital multimeter, it won't work if you only have an analog one.

[Wyluli]

Following your information, here is what I ended up with:

STR30130 Mine is actually STR3123 from a 19" WG K7000

1 to 2,3,4,5

[menace]

not sure what you meant by no reading--does the meter zero?  My guess though is that they are both toast.  pm me if you need a new one--i bought a bag of ten awhile ago and have some extras. 

[Wyluli]

not sure what you meant by no reading--does the meter zero?

[Wyluli]

*Bump, hoping Ken has advice on this...

The regulator IC will have a thin mica insulator between it and the aluminum frame. Don't forget to smear a thin film of silicone heat sink grease on the insulator and the rear of the replacement regulator IC.

I replaced the voltage regulator, but now my monitor will not turn on.  I took the old one off, applied thermal paste to the back of the new one, and soldered it on.  *NOTE: I forgot to put the thin mica insulator on the back of the regulator, I just put thermal grease.  [IDIOT  ] 
When I turned the machine on, I heard a brief sound from the monitor, then nothing.  Nothing comes on at all, not even the marquee light, coin door lights, etc.  And if I try to power it up again, nothing but silence.

P.S. Do I need to put thermal paste on both sides of the mica insulator?
What do I do from here to get this monitor working again?

[Wyluli]

* Bump, still need help on this....   
Sorry to be a *bump hog*

[menace]

Yes, put paste on both sides of the mica (a little dab will do ya) and as far as where to go from here, I would check the voltage regulator (STR3123-since you have the 19" version) using datasheets of the internet and you should also check C57 and check the voltages on the large white resistor to see if you have anything.

[Wyluli]

Yes, put paste on both sides of the mica (a little dab will do ya) and as far as where to go from here, I would check the voltage regulator (STR3123-since you have the 19" version) using datasheets of the internet and you should also check C57 and check the voltages on the large white resistor to see if you have anything.

I'm not finding any information that tells me exactly what to measure and how.

[menace]

I'm not going to say its not your main filter cap but I've never heard of one going (albeit my experience is limited) what i have seen is c57 go, R103 go, IC2, IC3, IC4 all go (not on the same board mind you)  I'm thinking if randy fromm says fire it up with no voltage regulator give it a go. (just keep your hands on the cord to disconnect it quick if need be  )

here's the datasheet for that chip:
http://www.datasheetarchive.com/datasheet/pdf/4744.html

from this you might be able to get what pins are supposed to connect to what other pins inside the chip.

[Wyluli]

I guess I really need a book or class or something that shows me exactly what to test and exactly how to test it with the mulitmeter.  I can find the parts on the board easy enough, but just don't know what to set the multimeter to or where to put the multimeter probes for the most part.  It would be nice to go thru each part and test it and KNOW if it has a problem or not.

Anyone have Randy Fromm's big blue book?  Is it worth the money?  Does it cover this kind of stuff?

I really want to get this monitor fixed, not just for the game, but because I'm genuinely interested in learning how this all works.  The web has not been a real great resource so far though.

If worse comes to worse, I guess I can purchase another chassis for the monitor.

[menace]

I'd like to help you walk you through it but its a big job and not easily accomplished via the web.  I remember wanting to learn this stuff but fortunately my brother had gone this road before and so I could just ask him.   I've put something in the FAQ now to address this--although it will be basic to start.

[Wyluli]

I'd like to help you walk you through it but its a big job and not easily accomplished via the web.

[Ken Layton]

Um.... when you replace the regulator on the k7000, there were several types. Replace the original with the same number only as the pin connections on the other types are different. The regulator will be destroyed immediately on power up. If the original on the chassis was a STR30130 then it should be replaced with the same number.

[Wyluli]

Um.... when you replace the regulator on the k7000, there were several types. Replace the original with the same number only as the pin connections on the other types are different. The regulator will be destroyed immediately on power up. If the original on the chassis was a STR30130 then it should be replaced with the same number.

My message string is getting long and confusing I know.
The original Volate Regulator was a STR3123.  The one I replaced it with in the message below was also a STR3123.  (I thought maybe the STR30130 might have the same pinout as the STR3123 and I could test it according to the instructions provided by menace, but found out from him that this is not the case and I could not test it as such)

I replaced the voltage regulator (STR3123), but now my monitor will not turn on.  I took the old one (STR3123) off, applied thermal paste to the back of the new one(STR3123), and soldered it on.  *NOTE*: I forgot to put the thin mica insulator on the back of the regulator, I just put thermal grease.  [IDIOT  ] 
When I turned the machine on, I heard a brief sound from the monitor, then nothing.  Nothing comes on at all, not even the marquee light, coin door lights, etc.  And if I try to power it up again, nothing but silence.

So now I am ordering another STR3123 (assuming the one I had installed is blown) and a new main fuse (as the main fuse in the machine was blown).  Hopefully it works, if not I probably fried something else, but no idea what?
WHERE YOU BEEN KEN? 

[Ken Layton]

I've been out of town since Tuesday morning. I just got back a few hours ago.

[menace]

wyluli--when you get the new voltage regulator please take baseline readings on the IC (like those I have for the 30130) this way the next guy like you who comes along has a known good starting point.  I'll add them to the FAQ.

[Wyluli]

wyluli--when you get the new voltage regulator please take baseline readings on the IC (like those I have for the 30130) this way the next guy like you who comes along has a known good starting point.