think the original LEDs may be a slightly different wavelength but if you going to change ALL pairs with the new 940nm LEDs then that should be fine, thats what i did it on my DW
bob

Just make sure they're the same length as the originals. I found out the ones I used were too long and when the targets were hit they stayed in and got damaged. So I took a dremel tool and ground down the new ones to the same size as the originals.

I only had to use the black ones. I can't remember which one is which though. I ground it down to half of what you see here. Which basically is the same as the original. Even if you had to grind the clear one it would probably work since it's in an enclosed space. However make sure when you're done that you cover up any holes where light can spill in.

IMG_2602 (resized).PNG

Yeah, I ground the top. You can also aim the receiver at an incandescent light and while measuring resistance you should see a change in value.

Oh, if you know how to test diodes then you can test the senders because they are "light emitting diodes" most DMM's have a diode test function.

I just went to my local Radio Shack and picked up a few. Used one to fix the one spot target that wasn't working right and it hasn't had a problem since. Everything fit nicely, too. So maybe I got lucky or something.

If I remember correctly, sometimes an opto failure in that DR. Who 5 bank can also be caused by warp in the plastic that holds the opto set.

Run a continuity check on every wire, connector, solder joint. You may have a bad connector, broken wire or cold solder joint. There's only a few wires, it will go quick.

Remember there's two bits to the 'opto'. An emitter and receiver. Plug in the connector to the game, turn it on and look at the LED emitters via a digital camera... the IR is picked up by the camera. Also, the LEDs are always emitting as long as the game is on... so, there should never be any LED off. The emitters are a little harder to test, but it's basically a light sensitive resistor. Put the legs of the receiver on your DMM (ohms) setting. Check the setting in the dark and shining a mag light into the receiver. If it changes values, it's probably good.... rinse and repeat.

Short of a component being dead, it's continuity... trace it all the way back to the backbox if you have to, but I bet the issue is with that 12 pin connector.

faz

Oh, here's a photo of the emitter.

P4020039 (resized).JPG

Hey Wayne-

Good To meet you today! So Did you end up having to grind down the transmitters after all? Just want to know going forward...

Original NOS Williams optos are available from my products page...

www.LockWhenLit.com/Products.htm

No worries about grinding, needing to change both sides, or incompatibility, they're original Williams parts.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

Well done sorting out the issues. Opto problems can be tricky.

I make mention of this in my thread on "how to determine the E & C of IR" here:

https://pinside.com/pinball/forum/topic/how-to-determine-the-c-e-of-black-opto-receiver-leds#post-3538582

An excerpt from that thread:

"While on the subject check out the excerpt from a Sharp Optoelectronics datasheet that mentions life expectancy of these IR devices (the Sharp parts have a very similar specification to the Everlight ones we use).

It talks about a working life of only five years before the device degrades by 50% - amazing. The ones in our pinball machines are 20 years plus and climbing so we can expect more issues with optos in the future I suspect."

IR_LED_LIFE (resized).jpg

Interesting... The miniplayfield ("Time expander") started going crazy up and down once I got my DW home, and I suddenly got a credit dot to inspect Mini Playfield Opto 5 - so back to the soldering station! I may order a bunch of these from you Rob - thank for the link! Wayne, thanks for the idea!

Wayne - I just looked at those instructions - glad you didn't give them to me ahead of time my attention span isn't 23 pages long! Just Get-R-Done is the easier approach! Remember I am an old man and had to be able to fix anything without instructions long before there was a World Wide Web with all this information.

And if you happen to look at this again tonight I tossed your Ghostbusters up on the Marketplace since you never did tell me if we were keeping it or selling it. Let the customers decide for you is my way of thinking at this point.

The guy for the other Doctor Who never contacted me so here we go again! Back up for sale but I didn't use the "flaked out" comment tonight. Too much heat about that last night!

Thanks Wayne ! The NVRAM is going to be a great help so I really appreciate that. I'll figure it out, should have time later in the week to disassemble the miniPF... Looks like it's not too bad to take off if you follow the guide. A littl clean up job and it should be good. I can replace the options if need be, but maybe that's not even the issue.

As long as that machine was sitting they might even just have some dirt on them that is keeping them from working correctly? I know from messing them up when shopping machines they need to be fairly clean to work correctly. Wayne will be your guy for advice on the optical part of things but if you have any questions about getting the time expander pulled out feel free to touch base with me also.

To be honest it was not all that bad to remove. Subway ramp has 5 screws & one plug on it and then once that is removed these are a total of 7 plugs on the harnesses for the time expander. Remove those and the "guide wheel" on the right side of the time expander (two nuts under the playfield) and you do the rest from the top. Total of maybe 15 minutes to remove it and that is taking your time.

You guys are way too generous! Tell you what, I want to order some more NVrams for my other games. I'll put in an order for those and if you want to throw in the optos, we'll call it a deal!

Will do. I think I'll skip putting it in my TZ, as I like how the clock tells the accurate time - and I installed a non-board battery holder. Thanks W!