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Aussie Pinball Forums => Technical Matters => Pinball Repairs / Problems & Assistance => Topic started by: mildflame on April 09, 2011, 05:56:26 PM

Title: Low GI
Post by: mildflame on April 09, 2011, 05:56:26 PM
I am havig a problem with my GI on a SEGA as it only has 3.2V AC at globes. Heave replaced fuse holders and fuses, Connecters, headers have been replaced, Direct from transformer is 7.2 and 2.2 AC. as the powere reaches the power supply board is is reduced to 3.2 and 1.9 AC. connector between ps board and transformer looks ok. Does anyone know where i may be losing my voltage or where i may be heading. PS. I have looked over the wiring diagrams.
HELP! :(
Title: Re: Low GI
Post by: MartyJ on April 09, 2011, 05:58:28 PM
Had a similar problem a while back, was definitely related to IDC connectors....

Beaky has just done a write up on rebuilding PSU for SEGA's....Might pay to PM him.
Title: Re: Low GI
Post by: mildflame on April 09, 2011, 06:02:05 PM
IDC Connectors have been replaced with TRI Furcon and soldered also.
Title: Re: Low GI
Post by: beaky on April 09, 2011, 06:23:35 PM
IDC Connectors have been replaced with TRI Furcon and soldered also.
what is the name of the pin as the early sega's used data east boards in them?
Title: Re: Low GI
Post by: mildflame on April 09, 2011, 06:25:03 PM
Frankenstien (same as Brett)
Title: Re: Low GI
Post by: mildflame on April 09, 2011, 06:28:42 PM
I also have a Data East Lethal Weapon 3 with same problem
Title: Re: Low GI
Post by: beaky on April 09, 2011, 06:32:42 PM
have you checked the g.i. plug at the transformer? (http://www.pinrepair.com/de/burntgi1.jpg)
if this plug is ok then and there is a low voltage on the input plug on the power supply you might have a short somewhere dragging the voltage down. check the 4 pin plug on the power supply top right corner, its the one with the wires soldered to the board see what voltage you have there. (http://aussiepinball.com/index.php?action=dlattach;topic=6288.0;attach=24200;image)
Title: Re: Low GI
Post by: mildflame on April 09, 2011, 06:35:46 PM
at the transformer connector the voltage was 7.2V AC and 2.2.
At the PS Board it was 3.2 and 1.9
Title: Re: Low GI
Post by: beaky on April 10, 2011, 12:45:30 AM
the 7.5 is ok at the transformer end but 2.2 is a worry. They should both be at about the same voltage at the transformer end and at the power supply G.I. input. The G.I circuit comes out of the transformer on 4 wires and goes into the power supply as 4. But the first thing that happens on the power supply board is both yellow wires connect together and the 2 white wires connect together. The yellow goes through the relay on the pwr supply board then goes out on CN8 pins 1 to 4 to the G.I. lamps. The 2 white wires go straight to CN8 on the pwr supp board pins 6 to 9, then to the fuses on the PPB board.

I would like you to look at the attached picture and let me know the voltages between the following wires .
Y1 & W1
Y2 & W2
Y3 & W3
Y4 & W4.
Next I would lke you to unplug CN9 at the power supply. (with the machine turned off) and test the above again.

Once I know these voltages then i will give you some more instructions
 
Title: Re: Low GI
Post by: mildflame on April 10, 2011, 11:01:15 AM
the 7.5 is ok at the transformer end but 2.2 is a worry. They should both be at about the same voltage at the transformer end and at the power supply G.I. input. The G.I circuit comes out of the transformer on 4 wires and goes into the power supply as 4. But the first thing that happens on the power supply board is both yellow wires connect together and the 2 white wires connect together. The yellow goes through the relay on the pwr supply board then goes out on CN8 pins 1 to 4 to the G.I. lamps. The 2 white wires go straight to CN8 on the pwr supp board pins 6 to 9, then to the fuses on the PPB board.

I would like you to look at the attached picture and let me know the voltages between the following wires .
Y1 & W1
Y2 & W2
Y3 & W3
Y4 & W4.
Next I would lke you to unplug CN9 at the power supply. (with the machine turned off) and test the above again.

Once I know these voltages then i will give you some more instructions
 
ok,  all measure 6.5V AC ( I was previously measuring to ground each wire)
Title: Re: Low GI
Post by: Caveoftreasures on April 10, 2011, 09:56:50 PM
The best thing to do is to have the power supply upgraded by having the caps n various other bits n pieces renewed like i did on my FRANKENSTEIN.
* Without even using a multi-meter, after 15 years plus of machine usage, i can guarrantee that it will be low on the voltage side of things. Check all connectors/pins on the GI side of things as well.

I know this sounds silly, but make sure all the bulbs are 44's and not low light 47's. Check all the 555's by comparing them to new 555's.
NOTE -The globes i buy from Mark C (PSP) are the best quality/brightest i have found. I recently swapped out all the bulbs on my Teenage Mutant Ninja Turtles , and Marks bulbs were so much brighter than the others i had previously purchased elsewhere. I dont know what brand Mark uses, but they are the brightest. Some of the others around are dull compared to the last batch i purchased and was very happy with.

Re the power supply, If u cant rebuild it yourself, wrap it well in bubble wrap, post it to Beaky, and have it made like new. It cost me apx $20 in parts. I am sure Beaky would conduct the work for next to nicks. PM Beaky or me if u want it overhauled.  ^^^
Title: Re: Low GI
Post by: studley67 on April 10, 2011, 10:09:22 PM
thanks for the advice brett,i think we are getting close now to solving it.transformer is good.the cn8 has its wires soldered to the board(euro hack)will now cut them so i can remove board and investigate further,tommorow.i will await approval from andrew,cn8 needs a new header,and connector,i have these parts on hand.i will update tommorow,damien
Title: Re: Low GI
Post by: studley67 on April 10, 2011, 10:47:18 PM
i plan to crimp the trifurcon pins to the wires and solder for good measure.
Title: Re: Low GI
Post by: beaky on April 11, 2011, 12:28:59 AM
We know now you have the correct voltage up to the power supply. Next you need to check how much voltage we are loosing through the pwr supply board and the PPB board.
 it is normal to lose around out 0.5 between the G.I Input plug on the power supply & the G.I out puts (one on the power supply and the other om the PPB board).

check the voltage at the G.I. input on the Pwr supply board.

CN9 Y3 & W3
CN9 Y4 & W4

Next check the G.I. voltage coming out of the power supply
CN8 Pin 1 (Brown) &  pin 6 (white / Brown)

Next check the G.I voltage out put on the power supply and PPB board
Pwr sup: CN8 Pin 1 (Brown)   & PPB J5 Pin 5 (white / Brown)
Pwr sup: CN8 Pin 2 (yellow)  & PPB J5 Pin 6 (white / YELLOW)
Pwr sup: CN8 pIN 3 (Green)   & PPB J5 Pin 7 (white / Green)
Pwr sup: CN8 pIN 4 (violet)  & PPB J5 Pin 9 (white / violet)

Again after I get these I will give you more instruction.

Just so you know i am trying to find out where the weak spots are that are causing the problem. It is a good idea to change the CN8 on the power supply. It maybe the plug you are changing or the tracks to and from the relay on the power supply board. or the plug for the fuses on the ppb. Also check the fuse clips on the ppp board. these fuse clips are know for thier cracking.
sorry it took so long to reply tonight.
Title: Re: Low GI
Post by: beaky on April 11, 2011, 12:32:30 AM

I know this sounds silly, but make sure all the bulbs are 44's and not low light 47's. Check all the 555's by comparing them to new 555's.
NOTE -The globes i buy from Mark C (PSP) are the best quality/brightest i have found. I recently swapped out all the bulbs on my Teenage Mutant Ninja Turtles , and Marks bulbs were so much brighter than the others i had previously purchased elsewhere. I dont know what brand Mark uses, but they are the brightest. Some of the others around are dull compared to the last batch i purchased and was very happy with.


Brett is correct about the lamps. the lamps that came with his TMNT where the worst lamps i have seen. just changing the lamps mad a huge difference. 
Title: Re: Low GI
Post by: studley67 on April 11, 2011, 12:39:58 AM
thanks andrew for all your help so far mitch and i really appreciate it,mate.never tested ac before(big lesson),ppb has 3.2 at fuse f1-f4 in respect to ground.header has been replaced,fuse clips,and connector with trifurcons,crimped and soldered.will investigate further tomorrow and report back,getting late
Title: Re: Low GI
Post by: studley67 on April 11, 2011, 12:54:54 AM
now!!!.... the 3.2 at the fuses is exactly half that should be there..hum....is half the ac cycle being clamped by a diode.ie controlled lamp shorted to gi lamp????    

memory trip back in school

after midnight,damien drunk............sorry
Title: Re: Low GI
Post by: beaky on April 11, 2011, 01:49:45 AM
now!!!.... the 3.2 at the fuses is exactly half that should be there..hum....is half the ac cycle being clamped by a diode.ie controlled lamp shorted to gi lamp????     

memory trip back in school
you need to have both probes on the AC wires. you wont get a correct reading if you tie one to GND or the earth strap. the reason why i gave all the different points to test is to determine were the voltage drop is and to make sure you have the both probes on each of the A.C wires. . the process of tests i have been giving you is the same way i test for a low G.I. fault.  ^^^ ^^^ ^^^ ^^^

I hope I didn't come across as rude with the above.  !@)
Title: Re: Low GI
Post by: studley67 on April 11, 2011, 02:04:16 AM
not rude at a;;.i have learned from this $#$
Title: Re: Low GI
Post by: beaky on April 11, 2011, 02:15:25 AM
not rude at a;;.i have learned from this $#$
i am glad you have it will help you determine G.I. faults and any other low voltage A.C. faults in the future.
I have also posted the diagrams and pics so if any one else needs them to sort out the same problem. ^^^
Title: Re: Low GI
Post by: studley67 on April 11, 2011, 06:38:00 PM
andrew,is this a  connector.if so where is it?
Title: Re: Low GI
Post by: studley67 on April 11, 2011, 06:58:59 PM
readings were

cn9's= 5.9
cn8's=5.71
cn8'8-j5's=5.49

now gi strings are 4.5
Title: Re: Low GI
Post by: beaky on April 11, 2011, 08:54:50 PM
readings were

cn9's= 5.9
cn8's=5.71
cn8'8-j5's=5.49

now gi strings are 4.5
All those voltages are fine for an early sega / data east. even the 4.5v on the strings. I just did a test on a last action hero that has the same G.I setup. all the voltages you have given me are very close to what I have . The machine i tested these voltages on has good g.i lighting.
There are only two things left it could be A, the lamps are 47's instead of 44's or you have a problem with the lamp sockets.

I will do a test on bretts sega just to make sure it equals yours
Title: Re: Low GI
Post by: studley67 on April 11, 2011, 09:04:20 PM
. ^&^ thanks very much for your paitence,at least i have learned how to test ac now.and now i know my way around this circuit,i will remember the lesson well,p.s. globes are 44,that i can get to,slings.mitchell has ordered some 555 spotlights to lighten the lower playfield area. &^& @.@
Title: Re: Low GI
Post by: beaky on April 11, 2011, 09:16:30 PM
. ^&^ thanks very much for your paitence,at least i have learned how to test ac now.and now i know my way around this circuit,i will remember the lesson well,p.s. globes are 44,that i can get to,slings.mitchell has ordered some 555 spotlights to lighten the lower playfield area. &^& @.@
sorry about putting you through all that. I measured the string voltage on the backbox insert and it was 4.5v. We know now that all your gi circuits through the boards are fine.
that is why your other data east looks dull also.
Title: Re: Low GI
Post by: studley67 on April 11, 2011, 09:34:13 PM
andrew also today i found a manufacture fault that you may want to look at on bretts.
i was testing resistance between cn8 pins 1-4 ac feed to playfield to ground.found a dead short with playfield down that whent away with it up...umm..left hand side with playfied up,i found a gi lamp that was earthing, as it was to close to the edge and touched the grounded sevice rails when pf was in the down position.food for thought,thanks again damien
Title: Re: Low GI
Post by: beaky on April 12, 2011, 11:25:34 AM
thanks mate i will check it out next time i am over at brett's. now i see why you were getting voltage readings across the ac and ground.