Bally SS GI Issue - Triac

[pinballnz]

Hi my centaur has no GI although the computer controlled lamps work fine. My mate ( tech) narrowed it down to the triac mounts on the steel plate next to the Power board. The part is Bally part # is E-585-67 or MAC-38-2 and is no longer available. This part was used on Elektra and Mr and Mrs pacman.

Can anyone advise if there is a part available locally and how did they mount it.

Regards
Clive

[Strangeways]

I've never had to replace this part, and it will be a case of finding a local substitute. GPE has a similar TRIAC ;

https://www.greatplainselectronics.com/proddetail.asp?prod=BTA25-600BW

[pinballnz]

Thanks for that but I would like to find a local supplier rather than order 1 part from the US as you can imagine the freight cost as well.
Regards
Clive

[Homepin]

BTA25-600 is a VERY common part

I would use Jaycar ZX-7149 which is actually a BT-137-600V-8A Triac because it has an isolated tab meaning you don't need to use any insulating washers to mount the part - much easier.

[pinballnz]

BTA25-600 is a VERY common part

I would use Jaycar ZX-7149 which is actually a BT-137-600V-8A Triac because it has an isolated tab meaning you don't need to use any insulating washers to mount the part - much easier.

Hi
I copied this info from a pinside thread about the original triac.
"The original MAC38-2 had a max gate current of 75mA"

As I am not an electronics expert would this part you suggest still be ok?
As the original part was screwed through the bottom steel plate how would you suggest mounting the jaycar triac? Just leave it lying on the steel plate or the bottom of the cabinet?

Regards
Clive

[Homepin]

drill  a hole in the steel plate and use a 3mm nut and bolt - that's why I suggest using an insulated tab type device as you don't have to be too fussy about mounting - just bolt it down.

Forget about specs like gate current etc, in the "olden days" components were always running close to the edge spec wise but most modern parts are MUCH tougher than those used originally. The one I have suggested you use as a replacement is physically 1/4 the size of the original but will carry x10 the voltage and current and is probably half the price the original was all those years ago.

This is a very NON critical application for this device and almost any triac will do the job equally well just make sure you Google the pinouts of the original and the replacement DO NOT assume the pinouts will be the same.

[pinballnz]

Thank you very much for your help. Stopped in at Jaycar and picked a few up. Also downloaded the pin out specs of both old and new triacs so I get that right.
Regards
Clive

[Homepin]

Excellent - let us know how you get on.

[studley67]

i have a similar issue with my GOLDBALL.following with interest.

[vanhos]

I had issues with mine on an elektra I replaced with ones beaky got me.

[Homepin]

I had issues with mine on an elektra I replaced with ones beaky got me.

Yup - that's the trick, just as shown in the pic

[vanhos]

Found the paper work beaky gave me to replace mine.

[pinballnz]

Hmm I have an issue.

I followed the pin outs M1 to M1 and gate to gate.  soldered them on and tested and same issue with the GI.  I left the old "earth " wires on a ring connector bolted to the old triac. Should these be soldered to leg 2? Should I run a new wire and ring connector to the old triac and then solder the wire to pin 2?

Thanks
Clive

[Homepin]

A triac switches MT1 and MT2 together (exactly like a relay) when the gate is activated. All it is, is an AC relay so all three terminals must be connected correctly for it to work.