What's new
By:
Pinball info

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

First Ever Board Repair !

DRD

DRD

Site Supporter
1 10 Years
Joined
Oct 26, 2014
Messages
5,583
Location
Newark
I had a solenoid immediately firing up on boot up which in turn fried the associated fuse.

Courtesy of the forum I have become a lot more clued up on such things. Having read the various threads on the subject I had already bought the relevant bits
  • A55KJ 60w Soldering Station from Maplin for £40. Good range of very small tips available. A major step up from the small gas powered one I have had in my tool box for years. I am OK at soldering as I did quite a lot of electronics as a child
  • Duratool D00672 desoldering station from eBay £67.50. I have never used one before. To an amateur like me, it is brilliant, makes desoldering a doddle. Highly recommended
  • TIP102 Transistors from Farnell. Pence
  • 1A slow blow fuses from Farnell. Pence
  • New diodes from Farnell. Pence
OK so I assumed that solenoid 2 was powered by Q2 transistor. Of course it wasn't. So I initially replaced a perfectly good original transistor with a new one. I then read the manual and spotted that solenoid 2 is actually powered by Q5 transistor. So I replaced this with the one formerly located in Q2

And the damned thing worked !!!
 
DRD said:
I had a solenoid immediately firing up on boot up which in turn fried the associated fuse.

OK so I assumed that solenoid 2 was powered by Q2 transistor. Of course it wasn't.
Click to expand...

The Stern games using the Mpu-200 board usually had the solenoid test number tally with the transistor 'Q' number. But generally it's best to check the manual, or the Help information on later systems, e.g. Bally '6803' or Williams WPC.

Well done with the repair.
 
Last edited:
Welcome to the elite band of nutters who seem to spend more time fixing their pins than playing them. If I'm honest, I really do enjoy doing the repairs, possibly more than playing, especially the electronics side of things. Really got into the Motorola 6800 CPU used on Bally machines. Fascinating device, so clever for it's time.

As for the A55KJ soldering iron, have you tried it on anything really meaty yet like coil lugs? I'm undecided as to whether it's better than my old fixed-temp 25W Weller iron, which although it takes a good 5+ minutes to heat up, seems to have a huge reservoir of heat. The A55KJ is brilliant, espcially with the extra pointy tip, for working on digital parts like chip sockets, but does seem to struggle a little heating up big chucks of metal like lugs.

I can't fault that extra fine tip though. A friend asked me if I could solder wires onto some LEDs which turned out to be 0.8mm wide so I ended up using 25 gauge wire from a broken coil!

SMD SMT 0603 Super Bright Green Light Led Emitting Diodes 1.6X0.8MM

$T2eC16hHJH0FG2hm,G27BS,8CJW3GQ~~60_12.JPG

$_10.jpg
 
Congratulations on fixing your board. One tip I learned about locked on coils is to always check (just replace it anyway) the coil diode first before starting board repairs because the first time this happened to me I ended up replacing a transistor about 4 times and almost ruined the board in the process.
 
We all live and learn! All pinheads have to pass The Rite Of The Smouldering Transistor! And then spend several days airing the house/garage to get rid of that awful smell :eek:
 
Thanks Pete. I had been tipped off to do this. I received a batch of diodes this morning in the mail so I was prepared ! Next day service from Farnell

The internet is just fabulous sometimes. I didn't even know my multimeter tested diodes. Some guy I had never heard of kindly puts a video online showing me how to test them and voila !

When you replace a board tranny, are you also meant to replace the diode that sits on the board too ? I am inclined to heat up the board as little as possible unless there is a good reason
 
I still have the scar on my eyelid when a quad nand gate blew up in my face when I was doing my GCSEs, though the wrinkles are masking it quite effectively now

Nedreud said:
We all live and learn! All pinheads have to pass The Rite Of The Smouldering Transistor! And then spend several days airing the house/garage to get rid of that awful smell :eek:
Click to expand...

I haven't tried the soldering iron on anything meatier yet. I tend to use my gas powered one for the bits mounted to the game - solenoids and the like
 
DRD said:
When you replace a board tranny, are you also meant to replace the diode that sits on the board too ? I am inclined to heat up the board as little as possible unless there is a good reason
Click to expand...

I guess it depends on the system. I don't recall ever having to do that on any Bally/Williams/DE/Sega games but I have had to replace the small pre-driver transistors before. I've had those bussed resistor networks go bad sometimes too, not often though.

I'm pretty sure diodes test reliably while they're still in the board so check if current flows in one direction only. @lukewells probably knows more about this.
 
They indeed do, but if they are on a switch remove the earth wire first then test the diode whilst activating the switch iirc..
 
I replace the diode when replacing the Q transistors. If the transistor is toast the diode has probably been stressed too. 1N4004 diodes are less than a penny each, and the board will be just fine.
 
You must log in or register to reply here.
Back
Top Bottom