The unregulated 12v TP1 reads around 9.5-10v. This is causing some of the optos to jitter during switch edge test. So I pulled the board and replaced both BR5 and C30. Hooked it back up and no change. I pulled the board off and metered for continuity all my soldering (which came out very clean) as well as verified continuity on all 4 pins of the new BR5 and the two points of C30. Then I traced continuity all the way from J112 to the fuses, to the BR5, C30 Cap, and it all tests out fine with my DMM. This circuit is very simple. There's only the input connector, fuse, br and cap. Can the BR be bad new out of the package? Any suggestions?

#2 11 years ago

ROB

Borygard

LockWhenLit.com

St Louis, MO

11y 90,050 2,915

Unfortunately continuity doesn't always mean a *solid* connection. You can read good continuity, but still have enough damage to the thru-holes to cause the circuit to fail. Run jumpers to/from the cap to be sure everything is solid.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
314-766-4587

#3 11 years ago

MKE

Pinballmike217

Pinside member

Naples, FL

11y 74,800 1,672

Jumpers are good idea but they don't look very good. Another option is to thread a jumper through the hole before installing a new cap. I cut a lead off a diode and, bend it into an "L" shape, scrape a little insulation of the trace on the board and solder it on. Then turn the board over, scrape a little of the insulation of the trace on the other side of the board, bend the wire over the trace and solder it on. If the hole is a little tight you can enlarge it with a scalpel. Then put the new cap in and solder away. The new threaded jumper lead gaurantees a good connection to both sides of the board.

#4 11 years ago

SWF

Nighthawk128

Pinside member

Edmonton, AB

11y 40,550 348 2

The power coming into the board is clean as well?

#5 11 years ago

ROB

Borygard

LockWhenLit.com

St Louis, MO

11y 90,050 2,915

Quoted from Pinballmike217:
Jumpers are good idea but they don't look very good. Another option is to thread a jumper through the hole before installing a new cap. I cut a lead off a diode and, bend it into an "L" shape, scrape a little insulation of the trace on the board and solder it on. Then turn the board over, scrape a little of the insulation of the trace on the other side of the board, bend the wire over the trace and solder it on. If the hole is a little tight you can enlarge it with a scalpel. Then put the new cap in and solder away. The new threaded jumper lead gaurantees a good connection to both sides of the board.

Yes, that's a great way to do a repair. There are lots of techniques for repairing damaged thru-holes, and although I generally do not use jumpers for my repairs, the average hobbyist probably isn't going to have the comfort or skill level to do a professional repair on thru-holes. Jumpers are a perfectly acceptable and quick way to do a repair.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
314-766-4587

#6 11 years ago

MVM

markmon

Inactive member

Hillsboro, OR

13y 98,300 13,010 21 81

Quoted from Nighthawk128:
The power coming into the board is clean as well?

Must be if swapping boards wouldn't fix it

#7 11 years ago

SWF

Nighthawk128

Pinside member

Edmonton, AB

11y 40,550 348 2

I measure 14V+ at TP1 and a hair under 12V for the regulated TP on my machine. Ya it's a simple circuit. If you replaced BR5 do the prodecture for testing it's values between the legs, it's providing power so I don't think it's bad. It's giving you the exact same value. Double check the resistors inline with that circuit and compare the results with the other board you have.

Something as mentioned by Borygard being solid connections, this might just work but either rotate or pull fuse F116 and clean it up with a scratch pad along with the seat it sits in. Seen stranger things. But also as mentioned if still haveing low voltage then try jumpers to ensure the connections are clean between components BR5/C30 etc.

-1

#8 11 years ago

TOX

ChrisHibler

Chris' Pinball Repair

Chesterfield, MO

12y 120K 9,993 46

I would at the very least, reflow J112. Or if tarnished, replace it.
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The new place for pinball repair info

8 years later

#9 2 years ago

SRL

AAAV8R

Pinside+ Frequent

Apple Valley, MN

6y 54,300 219 7

Looking for help on my TOM. This is my first time working on this system.

12v unregulated appears to be out. Measuring .96v at TP1. LED 7 out. All fuses test OK.

I unplugged J116, J117, and J118. LED glows dim, and TP1 only reads around 2v.

18v power is good, and 12v regulated also tests good.

————————————————

Machine powers up, but does not run self test. No DMD. Attract mode appears to be running normally. Press start switch and nothing happens.

Any suggestions on next steps appreciated. From my novice research, it looks like C30 or BR5 the likely suspects?

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