WH20 Lamp Row issue

[Wotto]

Bad transistor or a dodgy lamp diode?
Or am I way off the mark?

WH20 – Lamp Matrix.
Row 2.
Lamp 82 in the game / or lamp 8 in row 2 comes on with EVERY other lamp in Row 2.

 

[Pinball Fixers]

If all the other lamps are working properly, then it is not a transistor.

So, check/replace the diode and see if that fixes it.


I had a similar problem on a pinball where someone had soldered a wire back on to the lamp, but on the wrong side of the diode... Made a few of the lamps come on when they shouldn't have, and others glow dimly.

[Wotto]

 Update - it is now worse 

Owen - I checked that diode on what was the main culprit - it tested fine.
I checked the wiring - it is all as it is meant to be.

SO I went to Marvin 3 guide - it advised to remove and re-seat the short flat strap between the 2 boards - I did that, and now........

Well now I have the original issue AND I also have EVERY light in coloumn 1 lighting up with its corresponding 'row' light from column 8.

Theres bloody lights on everywhere  .......................


As a side issue I did find that ONE of the diodes on a seperate lampholder is reading value when tested both sides ( is that 'open' ? )
BUT that particular lamp is in column 8 - it was not part of the original row 2 issue- but now that column 8 has come into play , then it is now involved - confused now everyone

Sheeeeeeeeeeesh - I am lost 

[Pinball Fixers]

SO I went to Marvin 3 guide - it advised to remove and re-seat the short flat strap between the 2 boards - I did that, and now........

Are you referring to the ribbon cable between the CPU and the Driver board? If so, then it can cause strange problems, but as it is address and data for lamps, coils, GI and so on, you are more likely to see other parts of the machine misbehaving and not just one lamp.

It is possible that the ribbon cable is now causing lamp columns 1 and 8 to act as one. I would remove and re-fit the ribbon cable again (and even turn it around) and see if the prob goes away or changes.


Back to the original lamp prob...

What does the diode measure (both measurements)?

The diode may be "out of spec" but not 'short' or 'open', causing the "ghosting" you are seeing. (By they way - 'short' means zero ohms, and 'open' means no reading at all, like the multimeter probes are not touching anything)


And what is the other diode you've found reading? Again, it might be out of spec as well...

[Wotto]

Are you referring to the ribbon cable between the CPU and the Driver board?

Yes

It is possible that the ribbon cable is now causing lamp columns 1 and 8 to act as one. I would remove and re-fit the ribbon cable again (and even turn it around) and see if the prob goes away or changes.

I did do that a number of times but I didnt turn it around - I will do that tonight.

Back to the original lamp prob...

What does the diode measure (both measurements)?

On the original lamp that was coming on with all the others it measured something like 570 one way and NIL the other- if you need the EXACT number reading I will get that again tonight  - yes 

And what is the other diode you've found reading? Again, it might be out of spec as well...

This is the one I found in column 8 that wasnt part of the original 'row 2' issue - It was also reading 560's / 570's BOTH ways - once again if you need the EXACT numbers I will get them again tonight- yes 


Thanks so far 

[Pinball Fixers]

Back to the original lamp prob...

What does the diode measure (both measurements)?

On the original lamp that was coming on with all the others it measured something like 570 one way and NIL the other- if you need the EXACT number reading I will get that again tonight  - yes 

OK, 570 is about right, and nil is also right... so no problem there (exact numbers are not necessary, as long as they are close to what you measured).

And what is the other diode you've found reading? Again, it might be out of spec as well...

This is the one I found in column 8 that wasnt part of the original 'row 2' issue - It was also reading 560's / 570's BOTH ways - once again if you need the EXACT numbers I will get them again tonight- yes 

Reading 560/570 both ways is not correct. Did you have the lamp in place when you measured? If so, remove the lamp and re-check. If you get the same readings, then replace the diode.


It is now possible that you do have a failed transistor or 2, or even a failed IC, but there are a few more things to check before we go for that...

Measure for a short between Columns 1 and 8. It could be that somehow they have shorted together causing this problem. If you do find them shorted, then remove the lamp matrix plugs from the Driver board and measure again. This way you'll know if it's in the cabinet or on the board.

[Wotto]

Measure for a short between Columns 1 and 8. It could be that somehow they have shorted together causing this problem. If you do find them shorted, then remove the lamp matrix plugs from the Driver board and measure again. This way you'll know if it's in the cabinet or on the board.

Hi Owen

Will pull that lamp and report back.

Excuse my ( well stated ) ignorance in regards to most things electronic……….but how do I measure for a short between columns 1 and 8 ???

[Pinball Fixers]

Measure for a short between Columns 1 and 8. It could be that somehow they have shorted together causing this problem. If you do find them shorted, then remove the lamp matrix plugs from the Driver board and measure again. This way you'll know if it's in the cabinet or on the board.

Hi Owen

Will pull that lamp and report back.

Excuse my ( well stated ) ignorance in regards to most things electronic……….but how do I measure for a short between columns 1 and 8 ???

No probs Wotto, I sorta guessed that from an earlier post when you asked if it was 'open'.

OK, set your multimeter to continuity test. This is the one where if you touch the probes together, the multimeter will "beep".

Then, place one of the probes on a column 1 wire, and the other on a column 8 wire. If it "beeps" then you have a "short circuit' or "short". If it does not then you have an "open circuit" or "open" - this is what it should be.

If you do find it short, then follow my earlier instructions...

(If you do not have continuity test on your meter, then let me know as there are other ways of doing this)

[Wotto]

Arrrrr – I can see this thread going longer than Ford Fairlanes infamous thread

Yes mate I have the continuity setting on my MM and I understand what you mean.

Look for my technical report back here tomorrow 

[Strangeways]

Arrrrr – I can see this thread going longer than Ford Fairlanes infamous thread

Yes mate I have the continuity setting on my MM and I understand what you mean.

Look for my technical report back here tomorrow 

not a chance - Ford's is stall an "active" thread !

Can we "back track" for a sec Wotto ? I vaguely recall there was another lamp issue with this game - can you remember the fault and the resolution ? It may be related ?

[Wotto]

Can we "back track" for a sec Wotto ? I vaguely recall there was another lamp issue with this game - can you remember the fault and the resolution ? It may be related ?

I think U are thinking of some bulbs that originally didnt work at all - one of them was one of the Hazard lights which made knowing where U were in gameplay a little difficult at times - from memory that was when I had a dodgy wire not pushed in correctly to connector 137 – it was the number 1 wire and we sorted that and it has been fine since.

What this current issue does is allows a few of the (6) Boulder Garden lights to be on a lot instead of one being on and moving around when the bumpers are hit – so you cant really tell what Boulder Garden values you have already scored or what the next one is etc etc - or similar to what I just described.

[Wotto]

Update tonight- no closer


* I re-tested that diode on the 1 x lamp  that I thought was dodgy and it tested fine- must have been me last night- I checked all the diodes on the appropriate bulbs again tonight and they ALL checked out fine with a 560ish reading one way and NIL the other.


* I removed the flat data cable and replaced it a few times, swapped it around – no change at all.


* Refer to the Lamp Matrix below to check that I did the correct thing here - I put the MM on continuity and I held one probe to a Column 1 lamp wire under the playfield ( Left Outlane ) and I held the other probe on a Column 8 wire ( Mystery ) and I got NO beep noise. I also did this with a couple of other 1 and 8 lamp combos to triple check it – no beep noises at anytime ( I did check my MM by touching the probes and it was functioning and beeping when I did that ) . I was also unsure whether to do this test with the machine on or off  so I did both and if it was meant to be off for safety , I am still alive 





So I decided to make exact notes of whats going on and show a pic of the lamp matrix below and the issues I have.
Here is whats happening in the Single Lamp Test
( using Column 1 down as an example )

Shoot Again( Column 1 ) - Lights with Light Extra Ball (Column 8)
Kickback ( Column 1 ) - Lights with Light Advance Raft (Column 8)
Left Outlane ( Column 1 ) - Lights with Mystery(Column 8)
Left Flipper Lane ( Column 1 ) - Lights with Boulder 5X Award(Column 8)


If you then go down column 2 and realise that
River R1 ( Column 1 ) - Lights with Light Extra Ball (Column 8)
River River 'i' ( Column 1 ) - Lights with Advance Raft (Column 8) etc etc etc and repeat that process for the first 4 lamps down EACH column then you should get the idea.

In other words the lamps marked with BLUE in each column 1-7 - light up with the corresponding lamp marked RED in column 8.

Obviously Column 8 is causing my grief?

[Strangeways]

All diode tests should be done with the machine off 

I'm thinking along the lines that there is either some sort of short between column 1-7 and column 8, but it would be difficult for column 1 - 7 to all be shorted to column 8.

Seems like a "logic" issue to me, as your test proves that the lamps in column 8 are switched on when the corresponding ROW is switched on.

During a normal game, are all the lamps in column 8 "on" ? I guess they would be 

[Pinball Fixers]

This is most likely a ROW problem now (and maybe column 8's transistor)...

At this point I would be replacing U16 - LM339 on the Driver board. This IC is the only IC that is connected to all 4 of the first 4 rows. You should be able to ignore the 4 transistors (Q87 - Q89) and the other 2 IC's (U12 & U13) at this stage.

Also, Q91 - TIP107 - may be out of spec, but less likely than the LM339 as the bottom 4 rows are working fine according to your tests.

Hopefully it's just the one chip, and you're back up and running.

[Extra Ball]

Thats the red-grey wire I had issues with on FT. Mine was cut on the speaker grille, in the bottom of the cab. Wouldnt hurt to check your wiring looms.