Circuit board on power supply

[John jackson]

would this keep my machine from getting stuck  in test mode on my sigma sg 150 b plus

[Chris-socal]

Did you mean “Keep your machine from getting stuck”? Or do you mean your reels are stuck?

This topic is very common in the Sigma thread. There are 3 power rails on the power supply. The 24v rail is for the stepper motors. If that rail is dead the reels will not spin, the game will err. The err codes are explained in the Sigma manual, I don’t have them handy.

If you have read any archives on people troubleshooting Sigma machines you will notice that the power supplies are notorious for having problems. You need to verify that you have all three voltages. 5v, 12v, 24v.

Personally I pull my power supplies and connected a light bulb to each rail to verify they work under load. The most common issue is the 2200uf capacitors but other things can go wrong with them. Use extreme caution if working on a switching power supply on the bench, don't go there if you aren't clear what you are working on. Just order one that works on Ebay for $75 or so.

Here is a good thread on the topic. Your PS may be this exact one or very similar.
https://forums.arcade-museum.com/threads/sigma-power-supply.232829/

Chris

[John jackson]

Ok thankyou for that video I'm glad that's one thing to check on the voltages , I have the voltages that I'm supposef to have , what I was talking about was is my machine when powered on goes into self teat mode and sdays waite s while and i do , i tried to reset and nothing is working and my denomination chip is a gal o1 .there is a circuit board on the outside of power supply with 2 rows of wire pins one being a input and other. Being an out put. I have only one cable going to it and that was the input side and nothing on the output side or any place for it To go to .So i engage the  reset  button and test. Button on power supply and nothing happens as of it never was even pushed and activated. I get the reals to spin a few times in small incraments but then goes to self testing mode and stays there displaying that .. now keep in mind the soft meters next to the ifnfo Center don't light up or even display a thing  at all . To  get passed this that test mode that goes nowhere do i need. To have a coin comparator . There is something I got to be missing that I'm not aware of . So no my reels move at boot up but goes in the test mode and that's where it sits

[Chris-socal]

It might help if we can see a picture of the board on the side of the power supply that you are talking about. I know Sigma's have those remote boards mounted on the door and some only have one connector going to them.
If the reels spin at boot then your PS is good. Something isn't connected or working right if the displays are not working, I suspect you would see an error code if you can get them working. Sigma's do throw error codes.

Chris

[John jackson]

Hey Chris . I think I might have figured it out . My vfd works but the LEDs don't so my thought is this , my machine gets stuck in test mode and it is probably trying to show codes or something and can't due to the led meters not working so that's why it's doing that , I'm sure if I fixed that then even my push buttons would work and I could access the settings and what not , how far off do you think I am on this idea

[Chris-socal]

That is exactly what I think. It is throwing an error but you can't see it. Follow the wire looms from the LCD readouts to wherever they go. It's possible the LED loom came unplugged from it's driver board.
You might have to pull that LED board and look at traces and solder connections. It's possible something as simple as a trace on the board or a pin has a bad connection.

Chris

[John jackson]

Well would you believe it In the process of checking out the meters the power supply quit working , now I'm going to have to figure out wich one but I think it's the main one with the test button on it. SO tell me how how screwed am I . (Sorry for the language ) Won't happen again

[Chris-socal]

The PS has been suspect all along. Just because you get a 5v reading doesn’t mean it’s putting out the correct amount of current. And worse, if it isn’t being filtered correctly it might have AC in it.
They are available on eBay.

[John jackson]

Ok I got the power supply going , here's the thing under load power isn't dropping out or anything now it was a lose connection . I did what you suggested and still nothing .I got my dvm and I was testing the driver boards and I'm getting power to both of them ,I'm afraid it might be the chip on the led digit boards all traces are goodi went through them and soldered everything that looked loose or looked like it had a cold solder joint . So it has to be the driver boards or the LEDs are toasted

[Chris-socal]

Could be although probably rare.
I suppose there is a way to find the digital signal wire to verify that the mpu is sending the data but thats a little above my head.
It sure sounds to me like the 5v rail is not working correctly. It might be giving you 5v, did you say you connected a load like a light bulb to it? I use a 12v bulb to put more stress on it.

[John jackson]

I will try that with a load I just know what the dvm was telling me and it was telling me power was getting to it .out of the 4 boards one has only worked up to this point and the other 3 I get this ticking that comes from them

[John jackson]

I did the test with the 12 volt light on the 4 volt rail and it's 4.8 with the 12 volt light and 4.8 with out the light and I held it there for a minute , the light don't fluctuate and neither does the power it's a solid 4.8 volt I did this even when powering up the machine  and it dont drop

[John jackson]

Either my board is bad or the led driver boards is bad because I tested voltage on the led boards and it's also 4.8 volts . Even my top candle don't light up . The only thing working is is the treasure wheel LEDs are and the vfd is working so maybe it's my CPU because it's sending power but no codes 
So I'll figure out something and somehow find a board that's verified works and see what happens . Or I could just part this machine out and take that cash and buy a different machine .i just don't know . It seems that this machine is hard to get anything for it

[Chris-socal]

Agreed, the 5v line is fine.
I assume you have turned reset key a few times. Does it make any noise or movement when you turn it?

[John jackson]

You know it doesn't realy do anything like that but one time I did only one reels spin backwards and then displayed a money symbol on the vfd . Bit since then yoi can turn the key hit reset and the test button on power supply ending in the same result it goes into self test mode and stays there . No noise nothing no lights but I think that's because no bulbs . It's weird it's like the mpachine wants to work but can't go any further then test mode please wait awhile and that happens after the reel spin some timrs it does one spin
Session and sometimes it will do it in 3 to 4 cycles then to test mode . It's never consistent. It also sometimes doesn't do nothing but displays a dash on my vfd . Sounds like I have a bad cpu and or my eproms are shot but why would my led driver boards be getting power but not work . The led digits shouldn't all be bad one would think so should I get a new cpu board or eproms because that's the only things that r  left correct

[John jackson]

Chris , so I spent most the night taking parts off of a board that I had gotten and replaced some parts on this one board I'm using now , and with good luck I got the machine going with sound and everything I got a couple bugs to work out. The led isn't working still and I did get it to flicker when I messed with the maxim chip  on the driver board  but that's it for that the bill validator is going heywire but the game did load and now i get a lamp com. Error wich I believe has to do which the led meter

[Chris-socal]

It might be that you are touching one of the leads on the driver IC and that is causing a momentary input. If the LED's do flicker at least you know they work.
Stuff like that is difficult to trace but when you finally figure it out you will have learned a lot. LOL

Chris

[John jackson]

Well I am going to have to contact Allen at klar and see if he has the capabilities to fix my led meter driver boards , I believe they are not working because I had the plugs in them wrong and I remember the cables getting hot and the chip that's black and skinny and long it's the only one on each of the driver boards well they were super hot as well . I probably cooked them bit besides the lamp comm problem my machine is almost ready to go . I ordered a cash box for it and the coin comparator .man it's been a rough journey with this machine . I want to thank you for your patience and help and every one else who have helped as well I say thank you

[Chris-socal]

If you can post a good clear picture in the Want to buy section we have several vendors who have parts from machines that were broken down. They might have those driver boards. Are they surface mount ICs? If not they aren’t that difficult to replace.

[John jackson]

Yes they are I just ordered a few of them . What I'm going to do is take a Dremel tool cut the ic out leaving the legs and solder the new ic  to the legs so it will be a much easier job to do and I won't have to worry about pulling up a trace