Check F114 F115 on TZ

http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Check_fuses_F114_and_F115_message

Hi,

I was adjusting my pop bumpers switches when suddenly several coils activated. I was in the test switches menu and nothing was responding anymore and the display was stuck on "Gumball Test".

I power cycled the pin and I got the message "Check F114 F115".
I checked and I could not find any shortcut anywhere.

The F114 is fine, only the F115 keeps blowing.
When I replace it and reboot, the coils are activated in sequence, then the F115 blows again and I see the message "Check F114 F115".

I've seen several post about the U20/U14 on the CPU board, how can I diagnose them to be sure they work or not ?

I think I've made a shortcut when I was adjusting the leaf switches, but do you have any idea what could have happened and how to solve it now?

thanks.

#2 8 years ago

DLS

bigd1979

Pinside member

Hagerstown, MD

10y 137K 14,191 8 78

Sounds liike you shorted the high voltage .lesson learned tho and sld do that with the power off . Definitely cld be that chip but also maybe some other damage

#3 8 years ago

SMK

TheLaw

Pinside+ Addict

Ann Arbor, MI

12y 162K 48,071 19 30 1

Uff...pita right there. Could have blown a Lm337EDIT LM339 or whatever it is.

#4 8 years ago

TOX

ChrisHibler

U20 (a ULN2803) on the MPU or an LM339. Refer to the PinWiki article, above.
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#5 8 years ago

DLS

bigd1979

Pinside member

Hagerstown, MD

10y 137K 14,191 8 78

U20 Failure Analysis.Another way to determine if there is a short to power on the switch matrix is to remove U20 and power the game on. With all the switch connectors installed on the CPU board, use a DMM and check U20 socket pins 18 to 11 (switch columns 1 to 8 respectively) for any voltage greater than 12 volts DC. In a working game, with U20 removed, socket pins 11 to 18 should show 12 volts DC. If higher voltage is seen, there is a short on that switch column on the playfield, or some other wiring problem. The flashlamp circuit could be shorted to the switch matrix, or the solenoid power, or even the 6.3 volt AC general illumination."...Then a useful bit about testing the U20 you just replaced with a DMM to check if it's still good. Do the above before moving on to suspect U14.Although, yes it's possible that U14 failed. Just not that often.

#6 8 years ago

LIO

Leo13

Pinside member

According to the wiki page, it seems the culprit is on the MPU. I started several times the game with the J210 disconnected and the F115 does not blow anymore.

I have another WPC (Indiana Jones), what is the risk to take its MPU and install it in my TZ ? Is there a chance I damage this MPU ?
Before using the desoldering iron and remove the U20 to test the voltage, I would like to try the easiest way.

#7 8 years ago

LIO

Leo13

Pinside member

Quoted from ChrisHibler:
U20 (a ULN2803) on the MPU or an LM339. Refer to the PinWiki article, above.
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

DO you lnow how many LM339 or U20 equivalent could blow in this case ?

#8 8 years ago

ZAZ

zaza

Pinside+ Frequent

10y 92,650 3,269

OP
Quoted from Leo13:
I would like to try the easiest way.

Cut leg U20-10 and find out if fuse still blows on machine powerup
Could disconnect J206,207,208,209,212 if not sure that there is still a short in playfield switch-matrix.

Also, with this leg cut, it is possible to measure resistance between pin 9 and 10 of U20. Likely close to zero Ohm.
cut leg 10.jpg

#9 8 years ago

TOX

ChrisHibler

OP
Quoted from Leo13:
DO you lnow how many LM339 or U20 equivalent could blow in this case ?

It's impossible to say. You might be able to identify HARD failed LM339s with a meter, but I've never tried. If you get continuity between the chips ground connection and any other leg, I'd call it hard failed (shorted).

BTW, getting the ULN2803 and possibly LM339s out without damaging the board is not simple and not for the novice. If you haven't done it before you might be better served sending the board to a pro.
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#10 8 years ago

LIO

Leo13

Pinside member

Thanks for the tip ! I'll try it.

#11 8 years ago

LIO

Leo13

Pinside member

Quoted from ChrisHibler:
It's impossible to say. You might be able to identify HARD failed LM339s with a meter, but I've never tried. If you get continuity between the chips ground connection and any other leg, I'd call it hard failed (shorted).
BTW, getting the ULN2803 and possibly LM339s out without damaging the board is not simple and not for the novice. If you haven't done it before you might be better served sending the board to a pro.
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

I have a desoldering gun with pump, isnt it easier to work with ?

#12 8 years ago

TOX

ChrisHibler

OP
Quoted from Leo13:
I have a desoldering gun with pump, isnt it easier to work with ?

Yes, that makes the job a lot easier.
Add some solder to each solder joint (on the solder side) before trying to desolder.
This helps heat the joint better for easier removal.
--
Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

#13 8 years ago

SMK

TheLaw

Pinside+ Addict

Ann Arbor, MI

12y 162K 48,071 19 30 1

OP
Quoted from Leo13:
I have a desoldering gun with pump, isnt it easier to work with ?

Needed

2 weeks later

#14 8 years ago

LIO

Leo13

Pinside member

I would like to thank you for your help. Today, I'm really proud of myself and I replaced successfully the ULN2803 on the MPU, and it fixed the problem !
My TZ is now working like a charm !

Again, thank you all !

#15 8 years ago

TOX

ChrisHibler