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TZ Advice Needed Please - GND. Short Row 1 Is Stuck Closed.

John Taylor

John Taylor

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10 Years
Joined
Oct 15, 2013
Messages
102
After 6 years in storage I have powered up my TZ at the weekend..... had this for 20 years and apart from a clock failure this is the first issue I have had with it.

I have the following error message, can anyone give me a starter on where to start looking / diagnosing please ?

After boot up the GI is on and the display animations playing, inserts not illuminated. A number of coils fire for a short while, gumball and launch ball (I think)

Many Thanks



upload_2018-5-8_12-2-19.png
 
First thing I'd do is reseat all the connectors. And have the batteries leaked all over the boards or did you have the sense to take them out before putting in storage?
 
Thanks.... already re seated all of the connectors... of my 6 machines in storage I took the batteries out of all of them except the TZ, which I thought was the issue. Amazingly the batteries have not leaked and there's no evidence on the batteries or boards of any leakage.
 
Try disconnecting the switch matrix connectors - J206/207 and J208/209. With those disconnected try powering on. If you still get the message then you know the issue is on the board (and I'd still suspect battery damage). If the issue goes away then it's a legitimate ground short somewhere on the playfield wiring.
 
I had the same issue/error with my TAF recently, loose wire. I'd disturbed an earlier fix by replacing the Thing Hand (which had its nails painted by a previous owner!). Anyway, I've not had the issue again and it's gone away after I'd moved the machine.
 
Thanks for the advice, will try the connectors... hoping its just playfield issue
 
There's a specific message for that, "Slam Switch Stuck Closed", which I once had to contend with on a week-old Harley-Davidson.
 
Usually see that message when something has worked loose on the flipper mech such as the eos. I'd look there first. Then I'd look more closely at the area underneath and around the batteries.
 
Thanks for all the help....

Had a quick look last night in the backbox and unplugged the connectors as suggested, GND error message did not display after this, have a message to check fuses F114 and F115.

Pretty sure there is no battery damage, picture of board attached.

I will lift the playfield tonight and check the wiring and areas suggested.

Thanks again John
 

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John Taylor said:
Thanks for all the help....

Had a quick look last night in the backbox and unplugged the connectors as suggested, GND error message did not display after this, have a message to check fuses F114 and F115.

Pretty sure there is no battery damage, picture of board attached.

I will lift the playfield tonight and check the wiring and areas suggested.

Thanks again John
Click to expand...

Looks like a lot of furring under the batteries, which I suspect is not a good sign. But I am no expert!


Sent from my iPad using Tapatalk
 
Is the switch matrix totally disconnected when the message about fuses is showing? If the cabinet section of the switch matrix, using J 212, is still connected you shouldn't have that message - the 'Always Closed' test switch, # 2-4, is connected via J 212. If it's not seen by the program, the assumption is made that the switch matrix isn't working, and that message is displayed

The original error message seems a bit odd to me; I'dve thought that the 'Gnd Short Row 1' should be followed by the wire colour rather than 'Is Stuck Closed'
 
Thanks for the help.

Just had another inspection of the battery area (removed the new batteries), the legs back to the board are pretty shiny with 'furry' deposits just under where the batteries sit. The batteries I tool out look fully intact so I do not think that this is the issue.

Removed 206 and 208 and then the message goes and I get the fuse message.

J212 still gives the fuse message whether connected or not.

I will check row 1 tomorrow and see if I can find the fault.... there's a few posts on pinside with the same issue but at first glance all seem to have different root causes.

Thanks again

John
 
I suspect it will be the cpu also it’s had 2 chips already replaced that control the switch matrix have a look on the back of the cpu could be a nasty repair
 
Get into switch test. Remove the switch matrix connectors. Choose a row pin. Short it in turn to each of the column pins. Move to the next row and repeat for each row.

Each connection should give ONE switch closure. If any give multiple closures then the cpu is faulty. Replace that socketed 2803 chip and test again.

If all the shorts give single closures then cpu is ok, and fault is in the machine.
 
Thanks for all the previous help... one year later I am now looking at this again. I have removed the CPU board to have a closer inspection. I guess it has suffered from historic damage as the CPU board has had two chips socketed and there is a jumper from one of the pins on the 2803 chip to the replaced resistor (see in the picture). I have had pin for 20+ years (my first pinball) so this is a very old repair.

I get the GND short unless I unplug J206, then I get the fuse message.

The service switches do not work at all so I cannot get into switch test mode.

I am thinking that I may buy a replacement CPU board but ideally would like to be certain its not a machine fault first.

Any help would be appreciated, thanks

John
 
Again, thanks for the help, I have replaced the IC and get the same issue.

I have done a little more diagnostics...

CPU LED sequence is OK

When I unplug J206 on the CPU board for the switches the message goes and I get check F114 and F115....

I have checked the playfield cabling for shorts on Row 1 and all looks OK, for the ones I can see, I am assuming the lower right magnet switch is the opto that is under a ramp

F115 is OK but F114 keeps blowing

LED 1 (12v) and LED 6 (18v) is off on the power driver board

Reading Pinside there has been similar issues and point to replacing BR1

Anyone help appreciated...

Many Thanks
 
Look at J206 I bet there is alkaline in there I had same problem once drove me mad.
The connector not board, look into it where it mates.
 
Just q quick update, all working now. It was a power driver board power issue, LED's 1 and 6 were off. This caused the ground short error message. Thanks to Phil at Pinball Heaven for a super quick repair to the driver board for me. Purchased a few bits to 'bling' it up also, pop bumper rings look great !. Thanks for all the help.
 
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