Sys11B blowing fuse

I have fixed a few issues, but if one of the techs jumps in, they will be better help. At least I can bump your thread up if nothing else.

#5 4 years ago

LAG

Nihonmasa

Oups yeah good point sorry!
J5-11 on the interconnect board

I followed it and J5-11 goes from the interconnect to J12-11 of the auxiliary power driver board.
If I reconnect J5 and disconnect J12, it is also ok, no fuse blown.

Issue with a rectifying bridge? Diod?

#6 4 years ago

TOM

Tomass

Pinside member

I would test the bridge rectifiers, the diodes on the aux power supply and the a/c relay until someone can give better pointers.

#7 4 years ago

DEC

GRUMPY

Pinside member

OP
Quoted from Nihonmasa:
Don't get what's behind it. A&C 50V?

One of these 3 solenoids is blowing the fuse.

pf (resized).PNG

#8 4 years ago

TOM

Tomass

Pinside member

Now you have some advice you can bank on!

#9 4 years ago

LAG

Nihonmasa

Thx tomass

Grumpy: disconnected one end of each, retried: still a blown fuse.
Must be something else.

#10 4 years ago

DEC

GRUMPY

Pinside member

OP
Quoted from Nihonmasa:
disconnected one end of each, retried: still a blown fuse.

Disconnected how?

#11 4 years ago

LAG

Nihonmasa

Quoted from GRUMPY:
Disconnected how?

Unsoldered the wire for each of them

#12 4 years ago

LAG

Nihonmasa

#13 4 years ago

TOM

Tomass

Pinside member

Until GRUMPY gets back to you, maybe check the ohms on each coil and the diode associated with those coils. He will get back to you though. He has helped me more times than I can remember and is the reason I have SOME tech knowledge at all.

#14 4 years ago

LAG

Nihonmasa

Yep, that was the first thing I did, and I changed the ones that seemed even a bit out of specs
I have come to think that it was either a dead short or an issue on the board itself.
But found no short
I plan on swapping the rectifiers and capacitors tomorrow as I luckily have them.

#15 4 years ago

DEC

GRUMPY

Pinside member

OP
Quoted from Nihonmasa:
Unsoldered the wire for each of them

Put these back on. I found a error in the manual.
Unhook the purple/yellow wire from both kickers. Then retest.

#16 4 years ago

LAG

Nihonmasa

Done, fuse blown
Changed bridges and capacitor: same

I followed traces and it goes to relay K1, could it be the culprit?

#17 4 years ago

ZAZ

zaza

Pinside+ Frequent

10y 92,650 3,269

If I'm reading the schematics correct, Fuse 4 on AUX-board protects solenoid 3a, 4a, 6a, 7a, 18, 20
The 4 solenoids on 'a'-side are also going through the tip36c on AUX-board. check these 4 Q's as well

picture:

police force solenoids fuse4aux.jpg

#18 4 years ago

DEC

GRUMPY

Pinside member

This is why you shouldn't look at schematics on a phone. I thought the second power wire went to j-11 but it really goes to j-12.

Quoted from zaza:
If I'm reading the schematics correct

1 week later

#19 4 years ago

LAG

Nihonmasa

Tried with a known good aux board => same issue
Any idea where to look?

#20 4 years ago

DEC

GRUMPY

Pinside member

Quoted from zaza:
solenoid 3a, 4a, 6a, 7a,

Did you check these 4 coils?

#21 4 years ago

LAG

Nihonmasa

Diverter coil is indeed blown.
Ordered a replacement and will check if something else arises
Thanks!

#22 4 years ago

DEC

GRUMPY

Pinside member