Transistor woes on Hankin (perhaps)

[deep six]

Got the Hankin Howzat working (sort of) I have a locking coil problem on one of my right top bumper.
I'm guessing it could be a transistor problem but the solonoid driver board has some weird arse transistors in it, at least weird when compared to the ones I have encountered on my Stern Galaxy.
The transistors look to have a diode built into one of the legs. A quick check on big daddy reveals they have nothing like this transistor.
I'm wondering if it is a special or do I just replace it with a normal style, I did note a couple of transistors look like they have already been replaced and they seem to be the standard style with no build in diode.
Any thoughts on this one appreciated.


Cheers

[ddstoys]

They do look interesting sadly have not had time to look that closely at my Empire strikes back looking forward to a few replies on this one..

[Retropin]

My guess is that its just a standard 4004 diode thats used as a block to prevent wash going back to the driver chips should it go short... looks to be the case, banded side to transistor.

Depending on what they are.. you could replace with a standard transistor ( TIP102, BC548 etc) and place a diode on cct from leg to pad.
Its not totally necessary... no other machines ive ever seen have this package design for protection. Just bear in mind that should the transistor short in future, there is nothing preventing it taking out the chip next up the line.
remember.. this was the most common cause of Spider chips failing on GTB Sys1.. simple diode protection would have prevented it

[Homepin]

Empire Strikes Back manual shows them as standard TIP122....???

[Skybeaux]

I'd say Gavin's right and somebody has modified it and added the blocking diodes for better protection.
You can use the same driver transistors that are on your galaxy driver board

[Mr Pinbologist]

I'd say Gavin's right and somebody has modified it and added the blocking diodes for better protection.
You can use the same driver transistors that are on your galaxy driver board

+1 to Ken's and Gavin's comments, i think the diodes are an add on, as when i worked on AP member Howzat (Ian's) howzat game, i had to put a couple of transistors into his game and it didn't have the diodes.

[Splinta]

What a neat idea - I have blown the 7406's and also the 74154 IC's from TIP122 failures on my Howzat over the last 20 years, so this is definately a future project for me

[deep six]

Just getting back on to this problem, looks like I need TIP102 Transistors and 1N4004 diodes, but is there any higher rated components I could or should use in this???

Cheers

[Homepin]

Just getting back on to this problem, looks like I need TIP102 Transistors and 1N4004 diodes, but is there any higher rated components I could or should use in this???

Cheers

They have worked OK for years - fitting higher rated parts will only create more smoke when there is a problem IMO.

I never bother with 1N4001/4002/4004 and only stock and use 1N4007 as they are rated at 1A 1000V and are EXACTLY the same price as all the others - I can't even work out why retailers even stock the others anymore??

[deep six]

Thanks Homepin

I thought I read somewhere there was a better replacement option for 1N4004, I probably read it in one of your posts.

Cheers Mate