solenoid board woes....help needed

[Sinbad79]

Yea so DOA.
I rebuilt the rectifier board and ditched the MPU board for an Alltek.

Following Clays guide, I connect J2 of rectifier and J2 of SDB, coils blow!

The original MPU board and SDB have signs of repair...shit work too I might add, with burn or blown marks on the board and around the connectors. Something bad has happened with the machine at some point but previous owner denies any knowledge.

I WILL double check the coils and diodes this weekend, and if all che k out, I'll try the rotten dog SDB I have handy to see if the issue is with the original SDB.

[Sinbad79]

U2 is an IC , I know how to test a diode and transistor.

[Homepin]

U2 is an IC , I know how to test a diode and transistor.

The only real way to test an IC is by replacing it but these ones are very cheap - use a socket so future faultfinding is simplified.

[Boots]

Yea so DOA.
I rebuilt the rectifier board and ditched the MPU board for an Alltek.

Following Clays guide, I connect J2 of rectifier and J2 of SDB, coils blow!

The original MPU board and SDB have signs of repair...shit work too I might add, with burn or blown marks on the board and around the connectors. Something bad has happened with the machine at some point but previous owner denies any knowledge.

I WILL double check the coils and diodes this weekend, and if all che k out, I'll try the rotten dog SDB I have handy to see if the issue is with the original SDB.

I wouldn't rush out and buy a new sdb, these things are always fixable, really simple too, and parts are always available.
Personally a board would have to be almost snapped in half before I would give up on it, I am just too stubborn
The Bally / Stern systems are a good start for a beginner because they are so easy to fault find.

[Strangeways]

If this is one of the typical eBay project games then STOP. I've seen some literal "shockers" lately with some horrendous board hacks and poor repinning. I'd take a few steps back and if you have repinned any connectors, don't assume they were correct to start off with. It sounds to me like the wiring of the coils is incorrect and by wiring the coils incorrectly, you can blow the diodes on the coils. What I would expect to see is the 1 AMP SloBlo fuse protecting the SD board. Go through each coil and measure the resistance. check the wiring to the coils.

J2 of the Power Supply should not be blowing coils. J1 is for the playfield, and it has your solenoid power and returns. If this is wired incorrectly, it could cause havoc with the SD board.

where are you located ?

[Sinbad79]

Nino, no not one of the eBay projects you are thinking of, it was a local SA purchase.

Regarding blown fuse, it was actually when J1 was installed not J2 as previously mentioned, my error.

I'm working through the board at the moment, replacing the resistors and diodes for those transistors which have blown. I am yet to look over the coil wiring, I will do that on the weekend, but I suspect that it's the IC's on the SDB which are causing the issue, I've removed them as well and have socketed , ready for replacement IC's .

Failing all that, if I don't have success this weekend, I''ll probably send this board out to someone for testing/repair.

Thanks for all your help to date, much appreciates

[Sinbad79]

Here is what we are dealing with, 4 transistors missing are those which keep blowing. I've replaced C23,C24 and C26.

I've verified all resistors are good, but have no way to verify capacitors. Will assume they're good.

So basically, all components now check out OK. IC's will be replaced and playfield coil wiring and diode replacement will happen this weekend.

If after all that it still fails, then a bonfire it is!

[Sinbad79]

UPDATE,
A simple DMM test of the capacitors on the blown transistors are also blown.

[Homepin]

UPDATE,
A simple DMM test of the capacitors on the blown transistors are also blown.

Sorry I can't understand your post..??? Are you saying that some of the capacitors are shorted?

[Sinbad79]

Yes, well at least in think so.

You've made me second guess myself so I've removed a 'good' cap and tested it out of the circuit, and it reads same as the 'bad' caps....so I'm guessing they're all good - probably a different reading because no transistors are in their respective locations

[Strangeways]

Nino, no not one of the eBay projects you are thinking of, it was a local SA purchase.

Regarding blown fuse, it was actually when J1 was installed not J2 as previously mentioned, my error.

I'm working through the board at the moment, replacing the resistors and diodes for those transistors which have blown. I am yet to look over the coil wiring, I will do that on the weekend, but I suspect that it's the IC's on the SDB which are causing the issue, I've removed them as well and have socketed , ready for replacement IC's .

Failing all that, if I don't have success this weekend, I''ll probably send this board out to someone for testing/repair.

Thanks for all your help to date, much appreciates

This confirms the problem is not the SD, but the coils on the playfield. The power for the GI lamps, control lamps, solenoids and returns are located on J1. Once you have repaired the board, check all the coils, especially the coils allocated to the transistors that keep blowing.

[Sinbad79]

Will do, and I'll provide an update once I know more.

[Ballywannabe]

Surely we are talkking J3 on the solenoid board here - top right hand .1 connector.  If things blow with just J1 or J2 connected you have serious problems!!

BTW, U1,3 and 4 are not strictly IC's, they are transistors in an IC package, hence my comment on testing them with the diode function.  I have never seen U2 go bad, but I guess anything can happen in pinball.

Looking at Q3, I would say the knocker coil is cooked!!  Go through everything methodically on the weekend if you have time.

cheers
Ian

[Sinbad79]

Q3 is a beauty isnt it !

U2 was already socketed so its had issues before, i socketed the rest last night.
U3 had also been replaced at some point (lifted tracks etc) - so i've gone through it properly.

No harm in changing them i guess - process of ellimination.

[Boots]

Surely we are talkking J3 on the solenoid board here - top right hand .1 connector.  If things blow with just J1 or J2 connected you have serious problems!!

BTW, U1,3 and 4 are not strictly IC's, they are transistors in an IC package, hence my comment on testing them with the diode function.  I have never seen U2 go bad, but I guess anything can happen in pinball.

Looking at Q3, I would say the knocker coil is cooked!!  Go through everything methodically on the weekend if you have time.

cheers
Ian

Agree 100%, this is the same experience I have had