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Complete Disco Fever

AlanJ

AlanJ

Site Supporter
5Years
Joined
Dec 27, 2017
Messages
8,553
Location
Leeds, West Yorkshire
This is an interesting story.
This arrived with me today:
917B5B7B-81D2-428F-8C26-5CC58C604952.jpeg

Williams “Disco Fever”. Non worker

The owner had it for sale on ebay bin £995. didn’t accept my £500 offer.

I only want it as a “prop” for my 1970’s glam rock / disco themed 60th birthday party in Sept. I thought it looked the part.

So, I did a deal with the owner. I’ll get it working, use it for my party, then back to the owner in working order. Seemed a fair deal to me. Satisfies my party need and my desire to get another machine back up and running. Starting to get the hang of these early SS williams machines.

Owner delivered it from St Albans to Leeds today! top guy!

It’s in reasonable nick and seems to be complete. I’ll take a closer look at it later this week.
 
Got nos flipper rubbers here Alan. I will post you a pair!
(They are a bit uv damaged due to being stored for over 35 years....😎👊🏼
Banana flippers are simply dreadful, converted a few to standard over the years but still not a great game....😉
image.jpg
 
new forest pinball said:
Got nos flipper rubbers here Alan. I will post you a pair!
(They are a bit uv damaged due to being stored for over 35 years....😎👊🏼
Banana flippers are simply dreadful, converted a few to standard over the years but still not a great game....😉
View attachment 137289
Click to expand...
@new forest pinball Keith that’s fantastic. thanks so much. ps remember the stern thin drop target you also said you had please. for my meteor.
 
Had a quick look over the machine. been stood 3-4 years. the batteries removed, so no battery damage. boards and back box all nice and clean and tidy. a few wiring hacks but nothing too bad. all fuses ok. will disconnect everything and start from the transformer tomorrow afternoon
 
! !!! That’s why he didn’t accept my 600 offer! Told me he decided to get someone to repair it instead. I refrain from cursing you Alan, good luck with repair.
 
I want the experience. sys 3. not many of those i guess.
at least Clare can’t moan i’ve got too many machines as this is just a loaner 😂😂😂
 
Transformer is good, psu board is good, all voltages present

hooked in the mpu and driver but no solenoids plugged in

No boot

bottom led on mpu board comes on immediately and stays on

did some quick tests in the back box, but need it out on the bench


07C1DD0E-81AA-4DF7-977C-F0679861D800.jpeg

Hooked up 12 and 5v. same issue. bottom led comes on immediately and stays on

reset circuit seems ok. pin 40 of mpu starts low, then goes high and stays high.

pinwiki suggests an issue with the roms possibly.

Board has had repairs in the past, some new ic sockets and a broken trace has been neatly wired back up on the rear of the pcb

reseated the roms, (may need to test them later)

logic probe on mpu data and address pins show nothing happening, so it’s not getting very far, points to prom/eprom possibly.

some of the work to replace sockets has resulted in lifted/missing pads, on the ram chips especially. might need to check continuity on all those too.

Going to have a good look at the schematics and trace a few things back with the logic probe.
 
Found that the top led is duff, doesn’t help with a correct diagnosis!!!! replaced with a yellow one cos i seem to have misplaced my bag of red ones.

EE2D113B-7155-430E-B0EB-87E37F727DCC.png

Now got both leds working. strangely since replacing the led, they both now flash on and then both out when i power on. looks like mpu is doing something. press diagram button and they both flash twice then go out. that’s a good sign.

Just replacing a duff led shouldn’t get such progress? i guess i’ve disturbed something else on the board in my favour. still need to find the problem and fix it properly.
 
Did more tests on the bench, it seems to be booting. So installed into the machine. Two leds lit and wont go out. That was just with the power connector. Getting nice 12.6v and 5.06v at the power connector. Put back on bench, boots ok, back in machine, doesn't.

Then repeated all that again and suddenly it boots in the machine??? Deffo got a duff component or loose connection somewhere.

I hooked it into the rest of the machine and got a boot. Score displays have lit up - although player 1 and 2 showing "2222222" - player 3 and 4 ok showing zeros. Credit / match/BIP showing 22 credits and 0 ball in play.

I can start a game, no sound, or erratic sound. flippers. pops and slings firing, some lights working, scoring seems to work, but player 1 score is corrupted with the 2222222's but does change as scoring happens. Seems to end a game, but then cannot restart a new game without a reboot.

Cant start a multi player game.

Cant get into the diag menus with the coin door switches.

So - a bit of progress, but a whole host of odd issues.
 
have you tried disconnecting the normal player score displays and then booting?,what does the master display say then?,I had display issues with my gorgar,and it turned out the master display was causing the issues
 
i’ll try that thanks. apparently the 2222222’s is possibly a connector to mpu board issue. so i’ll check that first
 
Player 1 and player 2 scores are acting up and so is the master display. i.e. it shows 27 credits then clock up 4 games and it goes 26, 27, 24, 23 - i.e. 27 instead of 25? Looks like there is either a data problem from mpu to the score display driver, or its the master score display board that's at fault.

Only clocks up one game

Unplugged player 1 and 2 score displays - managed to start a multi player game

swapped player 2 and 3 score displays and the problem with the 2222222's moved from p2 to p3. So its the master board or the mpu.

Not sure where I go from here.
 
I think you've plenty of working games now in the system 3 to 6 variety..? Swap a few displays over and start ruling out faulty stuff. Other possibility is to invest in a complete set of new led displays.
 
Looked at schematic - the p1, p2 and credti matcch display are all driven off the same part of the circuit IC5 and IC9 - the A1-D1 BCD data - the A2-D2 BCD data is fine and powers the P3 & P4 displays.

Traced the wiring back to the MPU board - it connects to 1J5 header. Maybe reflow those, also I think I'll swap the 621 PIA on the MPU board. my (limited) experience has show that those are often faulty. And it does provide outputs for the core displays.
 
Moonraker said:
I think you've plenty of working games now in the system 3 to 6 variety..? Swap a few displays over and start ruling out faulty stuff. Other possibility is to invest in a complete set of new led displays.
Click to expand...
Ive got different types of displays in the other William games. I guess you could swap them over temporarily, they look pin compatible even though totally different boards and display designs. is that right?
 
AlanJ said:
Ive got different types of displays in the other William games. I guess you could swap them over temporarily, they look pin compatible even though totally different boards and display designs. is that right?
Click to expand...
I was thinking like for like swap but if the pin outs match... likewise could be a test for your led display project?
 
Hmm not sure they do to be honest, but anyway, Started to probe about with oscilloscope and looks like missing bcd data - so takes me back to the mpu or the wiring.

Wiring all checks out ok.
 
Ok so i put the mpu bcd data for players 3&4 into the player 1 & 2 side of the circuitry and the displays show the correct values, so this proves the master display board and the 4 score displays are all working fine. i was concerned it might have been one of those high voltage driver chips on the master display board

Pia swapped but still an issue. re-soldered the header pins and we have success

95B40B14-120B-4148-86E8-6905DDA4C6AD.jpeg
all 5 displays working perfectly

got a bit of a boot problem: it only boots on second power on. never first time.

once it does boot, i can start a game, multi player working fine now.

3 bank drop target not resetting. coil ok.

traced back to tip120 q17. faulty. so out with the old

4D6022D4-9A03-4A72-930B-E53DC31C7D0F.jpeg

in with the new
26750B00-7C86-41E1-B693-AA30980B329D.jpeg
Tip102 better than the old Tip120

Now got a full set of solenoids working.

Sound is strange, intermittent. That’s my next thing to look at.
 
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