My Paragon has recently become a bit unstable, occasionally locking up, and sometimes also blowing the playfield 1A solenoid fuse.
First happened back at Thanksgiving when people were over. I wasn't there when it happened; found the playfield fuse blown; replaced it; all good.
More recently, I've had it lock up on me in the middle of a game; or after sitting idle for a bit. Getting a bit more frequent.
- General Illumination remains on
- Displays go dark
- Controlled lamps go dark (any "thousands" score or other indicators)
- Cannot add a credit or start a new game
- Kickouts and flippers don't work
- Cannot go into test mode
- I can restart the game by powering off/on
- I have put it in test mode, and ran through all the solenoids for about 10 minutes
- a while later when sitting idle and solenoid locked on and blew the playfield fuse
- occasionally also locks up on power up, but rarely... it's usually after it's been played or sitting for a while
- assuming it's temperature or noise related
- other posts with similar issues have pointed to Solenoid Driver Board, or possibly power.
- I believe the solenoids occasionally locking up is secondary effect, since it doesn't always happen... assuming the MPU is sending out some random garbage when it hangs, and occasionally locks a solenoid on.
- On startup I get one flash, then 7 flashes, then green LED stays on but with lower visibility than flashes... when locked up, it goes completely dark.
Pictures of circuit boards attached
- MPU is TwoBits after market
- Other boards look original
- I've repaired the Sound Card (separate thread last year)
- I've replaced one of the power connectors (GI pins were cooked)
- compared to other peoples photos, it looks like the big caps on the Solenoid Driver Board may have been replaced?
- One resistor (R34) on the SDB looks like it was cooked and replaced at some time
- lots of harness wires have had electric tape added near connectors where insulation has become worn. I have some shrink tubing to eventually fix that, but up to now, it hasn't really caused me any problems.
Looking for feedback on
- possible root causes, based on symptoms
- opinion on locking solenoids being a secondary effect, or if they could randomly be locking (caps/diodes) and pulling down the MPU as well.
- Do boards look like they've had any "bullet proofing"... if not, point me in the right direction
- any other photos you want to see
- what to check when it's not locked up
- what to check when it is locked up
I'm a firm believer in diagnosing the crap out of an issue, and coming up with possible root causes that address all of the symptoms, before I start changing stuff. Not really a shotgun approach kind of guy for these old boards (and old skills!)
Power Supply (front... never have taken it out)
Solenoid Driver Board with some closeups