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Dreaded BSD Mist issue

newdos

newdos

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10 Years
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Jan 14, 2013
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Hartlepool
Hi All,

Mist not working on my BSD so I replaced C7 and C10 as advised on the 24" opto board. At first it didnt work but once the machine had been on an hour it started working fine and in switch edge test mode I could interrupt the long beam opto and all was good. Once machine has been off for a while said opto stops working!! So question is what component on the board (or is it the opto itself) is at fault here???

Cheers in advance

kev
 
Sgt GrizZ said:
What do you mean by 'not working' exactly ?

What isn't working ? Staging the ball ? Moving the ball ?
Click to expand...
Hi @Sgt GrizZ ,

I mean the 24" opto switch isnt working - ie go into switch test and blocking the beam no longer registers anything where as it does when the beam is working.

Cheers

kev
 
Change the optos themselves. Not worth messing about until you know these are new, clean and aligned perfectly. The special board drives the optos harder over a longer distance, but they are just the poor old regular parts that normally are opposite each other at a max 1" distance. Typical WMS design.
 
myPinballs said:
Change the optos themselves. Not worth messing about until you know these are new, clean and aligned perfectly. The special board drives the optos harder over a longer distance, but they are just the poor old regular parts that normally are opposite each other at a max 1" distance. Typical WMS design.
Click to expand...
ok and these are standard optos used in all the normal opto switches yeah ?
 
Check the 1mH inductor on the board. It’s been known to snap off under the component body.
 
The opto is used a bit like a remote control works. It emits a pulsed signal rather than permanently on. The detector looks for the pulse. That means that traditional ways of measuring the voltages on the Optos doesn’t apply.
 
thanks guys yes I have replaced the inductor first job I did - can I just confirm it is 10mH as per schematic and not 10uH as per board schedule @pinballmania ?

Cheers

kev
myPinballs said:
I have inductors and optos if you need them and the optos
Click to expand...
hi are these the new 940nm optos ? if so price per pair please ?

cheers

kev
 
newdos said:
thanks guys yes I have replaced the inductor first job I did - can I just confirm it is 10mH as per schematic and not 10uH as per board schedule @pinballmania ?

Cheers

kev

hi are these the new 940nm optos ? if so price per pair please ?

cheers

kev
Click to expand...


They are the exact original spec made by oem manufacturer Fairchild. The value is 880 I believe. I've used these for over a decade and never let me down

Prices are on my consolidated parts thread or as you saw on eBay
 
myPinballs said:
They are the exact original spec made by oem manufacturer Fairchild. The value is 880 I believe. I've used these for over a decade and never let me down

Prices are on my consolidated parts thread or as you saw on eBay
Click to expand...
cheers ordered via ebay
 
Excess ambient light can affect the opto performance and a maladjusted gate can impede the light beam.
 
myPinballs said:
They are the exact original spec made by oem manufacturer Fairchild. The value is 880 I believe. I've used these for over a decade and never let me down

Prices are on my consolidated parts thread or as you saw on eBay
Click to expand...
Jim,

Can I check this need to be wired the standard way round and not reversed like some of the replacements I have read about ?

Cheers

kev
 
newdos said:
Jim,

Can I check this need to be wired the standard way round and not reversed like some of the replacements I have read about ?

Cheers

kev
Click to expand...


Transmitter (Clear/PInk) - Short leg cathode

Receiver (Black) - Short leg emitter

Thats all you need to know! and the same as Williams original parts i believe
 
myPinballs said:
Transmitter (Clear/PInk) - Short leg cathode

Receiver (Black) - Short leg emitter

Thats all you need to know! and the same as Williams original parts i believe
Click to expand...
cheers Jim - will let you all know if this does the trick!!!

Kev
 
So, I first replaced the opto transmitter that I got from Jim at @myPinballs . It worked for one minute and then stops working!!! then I replaced the receiver and the say worked for a minute and stopped working I re made all of the IDC connections on the connectors on the board and still the same

Anyone any Ideas ? it seem like one board is powered up it fails after a minute ?

Cheers

kev
 
Are you saying it works in switch test for 1 minute after power on each time or only once ?

Have you confirmed that the transmitter opto is on (pulsing) by using a phone or digital camera? You can also use a logic probe here on the output to confirm a pulse from the 555 ic.

Have you buzz checked your wiring from optos to board?

Have you checked that ambient light is not a factor near the receiver?

Have you check the alignment of the receiver opto?
 
Last edited:
Hi Jim/Andy @myPinballs , @pinballmania

Yes done all of those to no avail !! I did try something tonight as soon as I switch the machine I go into switch edge test mode in #82 comes up straight away on the display indicating the beam is working. As soon as I block the beam it goes off, unblock it, it comes back on the display, exactly as it should. So I think this also rules out alignment and bad connections etc.

However, after 50 seconds or so the switch on the display starts flickering on and off quickly for about 5 secs that remains off for good(until I power down leave it and put it back on after an hour or so). So I really think this points to a component breaking down after power up and perhaps warming up. Cant be capacitors as I have replaced them.

any ideas guys greatly appreciated - determined to fix this !!!!

Cheers

kev
 
Kev @newdos could it be the power dropping off that supplies the opto board? Are you able to hook up a DMM, see what the voltage to the board is when you first power up and it's working and then just leave it connected. When it starts playing up, see if the power to the board has changed (maybe dropped low)?
 
ronsplooter said:
Kev @newdos could it be the power dropping off that supplies the opto board? Are you able to hook up a DMM, see what the voltage to the board is when you first power up and it's working and then just leave it connected. When it starts playing up, see if the power to the board has changed (maybe dropped low)?
Click to expand...
I'm sure I checked that ages ago, but will check it again. However I would of thought if the 12v rail is falling all sorts of other issues would have arisen as well @ronsplooter

Cheers

kev
 
My initial thought on your summary would be to get a logic probe and test the pulse output of the 555 at power on and then when you detect the issue develop. This will tell you which 'side' of the board is at fault hopefully.
 
myPinballs said:
My initial thought on your summary would be to get a logic probe and test the pulse output of the 555 at power on and then when you detect the issue develop. This will tell you which 'side' of the board is at fault hopefully.
Click to expand...
ok Jim I have a logic probe somewhere!!! I will find it and test the output of the 555 timer. Meanwhile here is a vid straight after switch on. this actually lasted 1min 30 secs before it died as I had to edit the video as to big. you can see the beam is initially on and I block it a couple of times with my hand then it just breaksdown.

if this helps in anyway let me know

Here is the you tube link


Cheers

kev
 
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