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Close uppic of a williamd System 4 master display

R

RichS

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Mar 17, 2022
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Bexhill on Sea
As some will know, I am trying to repair the Master Display on a Williams Flash. When I started everything displayed OK apart from The "D" segment on players 3 & 4 was out. The 10K resistor was OC and had burnt out. If I swapped the diplays into Players 1 or 2 they worked fine so I am 100% certain it is not the displays. I replaced the 10K resistors and I ordered 2 x ULN 7180A display drivers, a second ,"just in case", and whilst I waited I put a DIL socket in.
My soldering is pretty good (ex-RAF) and I have checked the socket for continuity and shorts with the rest of the board and all is good. I checked all the volts and connections on 4J7 and they are spot on. Apart from IC4, the master Display Digit Driver, all other horizontal IC's show the slot to the left. I assume this is the case for IC10?... Putting IC10, connecting it up and powering on, the game boots up, (new NVRAM fitted) ,and the game plays but without displays at all. Under a magnify Glass, I have checked the board for shorts and reconfirmed all the voltages.

The board and the slave displays are totally dead with no sign of life at all! Sadly I dont have another display to try it on. I have put in an NVRAM but have not yet set up the settings in the game. I any event I cant without working displays. I cant see how the displays would be affected by a new NVRAM unless it has in some way damaged IC 18 the master display output on the CPU. Has anyone any Idea? I do not have a scope or logoc probe
 
What happens if you put the old chip in? Think you ordered the drivers from China, good chance they dont work.
 
Moonraker said:
Sounds like a duff 7180, or inserted the wrong way round (easily done). Have you tried it by using the old one?

It might be worth working your way through the pinwiki on displays:

Williams System 3 - 7 - PinWiki

www.pinwiki.com www.pinwiki.com
Click to expand...
If that were the case surely it would only affect players 3 & 4. I put the IC in the correct way according to the manual with the slot facing left. Thank you for the like, it may help
 
drhex said:
What happens if you put the old chip in? Think you ordered the drivers from China, good chance they dont work.
Click to expand...
I had to order from China as could not find a UK one, Nikko buggered me around so much I gave up in the end. I any case without a 7180, (IC10), or not there at all surely it would only affect players 3 & 4?
 
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Problem is partially solved. I put a socket on IC10 (UDN7180A) as I has missing segments on players 3& 4. Waited 2 weeks from China as I could not locate a UK supplier , (forget Nikko Electronics), so had to go to China. The Board layout shows this chip with the slot to the left , like every other IC apart from IC4. Powering up there was no displays at all and a burning smell. The new Chip (IC10) has cooked. When I remove it all displays operate apart from 3 & 4 which is to be expected. Either I am going insane or my Chinese IC is crap or they have put the slot the wrong way round. Can anyone please confirm that the slot on the chip is fitted to the left as per the layout drawing. Any advice much appreciated. Anyone know where I can get reliable UK stock of a UDN 7180A?
 
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Moonraker said:
First search on ebay...
Click to expand...
Moonraker said:
First search on ebay...
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Moonraker said:
First search on ebay...
Click to expand...
Hi If you look at a my post at 2.20 I did go to Nikko but they messed me around promising the earth and delivering nothing. I then discovered they were merely "drop shipping" this item China buyting for £2.20 and charging £16+ I have since discovered that ULN 2003 OR 2803 are equivalents. D you know which way round the chip should go?
Click to expand...
 
Chip direction is normally marked on the circuit board. The holder should then be matched so anyone adding a chip later knows the correct direction in which to insert it.
 
Either a little half circle or notch on the top side next to pin 1 or a small circle on the actual chip next to pin 1.
 
Paul said:
View attachment 283971
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Thank you for this. I am aware if IC Polarity etc. The reason I am questioning it is that most IC's on the board are showing the indent to the left and pin at bottom left with the pins incrementing anti clockwise, however there is IC4 that is the other way around. I put the 7180 in the DIL socket with the indent to the left , like the majority of the IC's on the board but when turned on the displays were all blank and the 7180 got VERY hot. Taking it out and all but players 2 & 4 returned OK, which was expected as IC 10 drives them.. I have checked the IC socket for continuity and or poor soldering but it is all ok. I have a dilema, either The Chinese supplied chip is faulty. Or it should be inserted the other way around. Has anyone a close up of a Williams Master Driver Board? The ones I can find on the net are too small or blurred.
I think I have also found an equivalent chip / chips The original 7180 is an 8 transistor Darlington Driver Array pINS 1,9,10 &18 are not connected.
A ULN3003 is a 7 transistor Darlington Array with exactly the same pinouts Flash Oly uses 7 outputs anyway A ULN 2803 has all 8 in the array so in theory eith is an equivalent. I have ordered both from Amazon, much much cheaper. I will let you all know how I get on. A good photo of the master display board would be greatly appreciated guy
Thank Richard.
 
Going by the drawing of the 'I.C.' circuit board, D-8000 (with the board itself screened 1D-2001-130-3), in the manual for Blackout, all the vertically-placed chips have pin 1 at the top, but IC4 is an exception to the horizontally mounted chips having pin 1 to the left; No.s 8, 10, 12 & 13 have pin 1 bottom left, but IC 4 has pin 1 Top Right.
 
Chinese are (in)famous for relabeling chips, would only buy as last resort and breadboard for testing first.
 
The data sheet shows the 0v and supply voltage pins, should be simple to work out the correct orientation from belling out the board.

Chris

IMG_2400.webp
 
Apart from Nikko Electronics, does anyone know where in UK, (or reliable European supplier), I can get these IC's please? also has anyone got a close up of the board to see how the chips are configured.
 
Well an update for everyone I am sure many already know DO NOT BUY CHINESE IC'S. I Purchased 2 UDN7180A Darlington driver ics via e****e and both exploded when fitted to the board. I put the original in and it works (with the missing segments), so I know it is the IC's Can anyone reccommend a reliable UK or european seller? I have tried RS , Farnell, Cricklewood Electronics etc but it is not even listed anymore as I guess low voltage LED /LCD has taken over. Any help appreciated, even if I can buy an old Board from somewhere and risk re-use!
 
It’s obsolete. There is one uk based seller on eBay £16.99 + p&p

Plenty of Chinese sellers on aliexpress. The trick there is to ignore all the cheap ones and go for one priced £6-10. More likely to be a genuine pull or nos.

If it still turns out to be fake, I’ve successfully got refunded when I have received duff fake ics from aliexpress. I also always pay on amex just in case aliexpress don’t refund, amex will (but that’s never happened yet).
 
If you only have one segment out - segment "d" on Players 3 & 4 - then that's just one failed element of the 7180 IC10. You could replace that one element of the IC.

The really good news, is that you already have a spare circuit in your 7180 IC. It is an 8-way driver ic, but the board only uses 7, so you have a spare.

1753259084721.webp
As you can see the "d" circuit is input on pin 8 or IC10 and outputs on pin 11.
The spare, unused circuit is input pin 1 and output pin 18. So cut the pin 8 and pin 11 legs off the IC then on the back of the PCB, jumper 2 wires, one between pin 1 and pin 8 and the other between pin 11 and pin 18.
Should fix it - AS LONG AS the spare circuit is not damaged!
(Note - there is also a spare on IC9 as well).
 
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