Gorgar score digit problem

[GORGAR 1]

Hi Guys,

Pls help why would I lose some sectors of my score digits/pls see photos-only credit window and player 1 and player 2.

Peter

[FirePower]

Hi Pete,

The fact that it's a common segment on P1, P2 and the master display suggests to me that the problem is in the segment drive area as opposed to a problem in the stobes or BCD input wiring or the BCD to seven segment decoder. 

It's hard too see which version of the master driver you have - but I think most used the IC drive.  If this is the case, and you can tell by the absence of lots of transistors on the master driver then, have a close look at the bank of 7 resistors towards the top left of the master board.  They are just under  where the left hand end of where the P1 display cable plugs in.   These resistors and the 18pin display driver IC (IC9) slightly lower and a bit to the left are the area of interest.

I have seen a picture somewhere - maybe on this site, of a collection of burnt out resistors in this area.  Driver chip IC9 may also be failed - if socketed you could try swapping it over with IC10 to see if the problem moves to the other displays - and if neither of these is faulty  I'd look next at the BCD to seven segment decoder.  Hope this at least gives you a start.
   

[Strangeways]

Hi Pete,

The fact that it's a common segment on P1, P2 and the master display suggests to me that the problem is in the segment drive area as opposed to a problem in the stobes or BCD input wiring or the BCD to seven segment decoder. 

It's hard too see which version of the master driver you have - but I think most used the IC drive.  If this is the case, and you can tell by the absence of lots of transistors on the master driver then, have a close look at the bank of 7 resistors towards the top left of the master board.  They are just under  where the left hand end of where the P1 display cable plugs in.   These resistors and the 18pin display driver IC (IC9) slightly lower and a bit to the left are the area of interest.

I have seen a picture somewhere - maybe on this site, of a collection of burnt out resistors in this area.  Driver chip IC9 may also be failed - if socketed you could try swapping it over with IC10 to see if the problem moves to the other displays - and if neither of these is faulty  I'd look next at the BCD to seven segment decoder.  Hope this at least gives you a start.
   

I'd say this description would be correct. The MDB looks like the common DX-8000 - The resistor band in the top left hand corner is where you start - It looks like one has been replaced already at some point.

I hope it is not the UDN7180N - These are VERY hard to track down. Should be a resistor - Do you know how to measure the resistance of a resistor ?

They are 10K each - You are looking for R5 - Segment "e".

Maybe take a photo of the upper left hand corner of the display board to confirm.

[GORGAR 1]

Thanks guys-um I'll have to seek help I think as I'm confused and not really up with all the stuff behind the BG I will have a look tommorow and see what I can come up with. Could I put the TW MDB in and see if that helps?

Peter

[GORGAR 1]

Hi,

I thought I'd swap the credit window/MDB over with my Time Warp and the problem is still there.

[Strangeways]

Peter - You took the display board (MDB) from the Gorgar and placed it in the Time Warp and the display has the same issue ?

Looking at that picture of the MDB - you can see the "e" segment resistor is cooked. That will be your problem. (Fifth resistor across the top - 3 smaller ones, one large, then your cooked segment resistor)

From memory - 10K ohm 1/2 watt - Should be available from Jaycar / Dick Smith. I don't have the schematics at hand to confirm, but a multimeter set to OHMs will confirm.

[GORGAR 1]

Yeah Nino I saw that cooked resistor and thought that's it but when I put the Gorgar MDB in my TW the time warp works fine/Bugger. How can that be? but with the TW MDB in the Gorgar the Gorgar still has the same problem?

Peter

[Strangeways]

Peter - Just to confirm - you removed the MDB (with the fault) to the TW - and it works fine ?

This sounds like it is a display (P1 or P2) OR the cable TO P1/P2.


Try this ;

Place the original MDBs in their respective games. We should have a working MDB in TW, and the assumed faulty one in Gorgar.

With Gorgar OFF, remove the P1 and P2 displays. Switch it on. The CREDIT display should be fine.

Switch off. Now connect P1 ONLY - does it work ?

Switch off - disconnect P1 and connect P2.Switch on - Report back.

I think that it is a cable issue at this point.

[FirePower]

Could I put the TW MDB in and see if that helps?

Peter

I'd advise others who may be reading this thread to use some caution when swapping WMS display bits around like this between machines - not all have all the 100V supplies fed to the actual displays - in Peters' picture you can see the single brown wire in a connector that is angled off at about 11 o'clock sort of behind the leftmost top (P3) connector. On machines that have it, this wire is fed into the harness that connects to the player displays. I have a set of WMS displays that  do not have this feed.  I'm not sure of the effect of putting one of these displays onto a master board with the extra feed?   Does anybody have knowledge on this?  There is also a comment on the board layout drawing mentioned above about this extra fed, but it's a bit cryptic to me. 

[GORGAR 1]

Hi Nino,

Yep did as you asked I put MDB back in there own machines then unplugged P1 and P2 and it worked, I then put P1 back in and it worked then I unplugged P1 and plugged in P2 and it DIDN'T work. So it works until P2 is plugged in.

Peter

P:S-I have to go to work so will read further when I return/thanks again all for your help

[FirePower]

A bizarre one, but it illustrates the benefit of having two similar machines!  I've never seen a schemeatic for these displays, does anybody have one available?  The board layout drawing is available at wwww.firepowerpinball.com   I guess it's possible that something in a cable in one of the Gorgar displays is imposing a fault back to the master display.

I'd follow Ninos' procedure but also at the master display end on the P1 cable look closely at the green wire on pin 13 and on P2 the green wire is on pin 7 - the green is for the e segment.  

Loooking at your picture the board has been worked on before - look at the resoldered pins on IC9 near top left and the replaced resitors on the P3, P4 segment drives.  As Nino says they are 10K 1/2W and at least one of yours needs replacing - I'd let my hair down and do the lot.

[Mr Pinbologist]

My bet is that, since soon as you plug P2 display in it stops the segments on the master display working.. have i got that right?? The fault will be the P2 display glass itsself. had the exact same problem with my Stellar Wars when i brought it home. went thru all the mucking around changing the 10k resistors only to find them burning again, then discovered pulling the connectors to the P1  and P2 displays all the segments came on, on the MDB. i had to replace TWO glasses, as the were both crook, burning different resistors and stopping different segments from coming on. Somehow the glasses were pulling the segment line down, burning up th resistors and causing segments to go out on the MDB. Replace the P2 display..

sounds like your lucky to only have to replace one display,, unlike me, was an expensive exercise!!

[Strangeways]

Could I put the TW MDB in and see if that helps?

Peter

I'd advise others who may be reading this thread to use some caution when swapping WMS display bits around like this between machines - not all have all the 100V supplies fed to the actual displays - in Peters' picture you can see the single brown wire in a connector that is angled off at about 11 o'clock sort of behind the leftmost top (P3) connector. On machines that have it, this wire is fed into the harness that connects to the player displays. I have a set of WMS displays that  do not have this feed.  I'm not sure of the effect of putting one of these displays onto a master board with the extra feed?   Does anybody have knowledge on this?  There is also a comment on the board layout drawing mentioned above about this extra fed, but it's a bit cryptic to me. 

Excellent advise - and something to remember.

I have the advantage of being the previous owner of the Time Warp - and I know both MDB are the same. So I knew it was safe to swap them over - but the point remains the same - check the revisions of the MDB and the wiring of the cabinet.

My bet is that, since soon as you plug P2 display in it stops the segments on the master display working.. have i got that right?? The fault will be the P2 display glass itsself. had the exact same problem with my Stellar Wars when i brought it home. went thru all the mucking around changing the 10k resistors only to find them burning again, then discovered pulling the connectors to the P1  and P2 displays all the segments came on, on the MDB. i had to replace TWO glasses, as the were both crook, burning different resistors and stopping different segments from coming on. Somehow the glasses were pulling the segment line down, burning up th resistors and causing segments to go out on the MDB. Replace the P2 display..

sounds like your lucky to only have to replace one display,, unlike me, was an expensive exercise!!

I agree - Played 2 display is the culprit. A simple test would be to swap the current (assumed faulty) P2 display with a P3 or P4 display. This will confirm the display is the issue. I would then permanently remove that display until it is repaired or replaced.

It might have dry joints on the board.

[GORGAR 1]

Thanks guys I swapped P2 with P4 and she works great so yeah P2 score window was the problem-I'll have to source a new score window now and she'll work a treat. Big thanks to Nino for all your help mate I really appreciate it and to everyone else who posted thanks this is a great site full of people wanting to help

Peter

[Pintoxicated]

Good that you found the problem in the end, bummer that it happened now.  I literally only ordered two glasses from the States last week and could have easily ordered one more.  Best I could find them for was $47USD.  Give Zivko a call, he mentioned that he has stacks of them but they are untested.  You could either try pot luck or Ken Shipley has a test bench to check them before you put them in a machine and risk and further damage anywhere.