Vector display problem

stevelup

New Member
Mar 17, 2019
5
3
3
Chiseldon, UK
I'm not a pinball expert, but looking at that schematic, the zener diode VR1 is a critical component that could cause these symptoms, and it's not a part you can test with conventional test gear. Basically, it will read like a normal diode one way, but then when you apply 140V across it the other way, it will 'break down' and start conducting. You can't properly test it with just a multimeter.

Given that you've changed all the other semiconductors, and tested all the resistors, not sure what else it could be.
 

pinballmania

Well-Known Member
Jul 21, 2011
1,779
1,026
113
Have you checked continuity to the bux 85g. It makes its connection via the nut and bolt.
 

pinballmania

Well-Known Member
Jul 21, 2011
1,779
1,026
113
You can also send it to me for repair if you like. I’ll do it for cost of parts and post only.
 

Vimtoman

Site Supporter
Sep 29, 2018
555
191
43
London
Replaced c27..No change.

I checked the bridge rectifier on the power board feeding the circuit with my fluke meter set on diode. I get no reading in one direction and a continuous beep (But no reading) in the other direction on each diode. Is that normal?

I then checked the diode in the HV section. On cr21 diode I get the same result: no reading in one direction and a continuous beep in the opposite direction. On vr1 I get a slightly different outcome: no reading in one direction and then a continuous beep and reading (0.5) on the meter. Again does it make sense?

My trolling of YouTube videos meant that I was expecting a reading on the diode to be between 400 and 600 in one direction and no reading in the opposite direction. I am not quite getting this.... any words of wisdom?
appx 0.5v with black lead on the cathode and red lead on the anode is correct.
black bar marking on the diode indicates cathode

The reverse should give no reading.

If you have a constant beep with 0.1 then thats a short.
 
OP
OP
domlouis

domlouis

Well-Known Member
May 28, 2014
1,040
474
83
Derby
Have you checked continuity to the bux 85g. It makes its connection via the nut and bolt.
Yes Thanks Andy. I figured that out when i looked at the back of the board and saw the bolt in contact with the tracks. I tested continuity when i was testing the tracks.


You can also send it to me for repair if you like. I’ll do it for cost of parts and post only.
Thanks again Andy and i might have to take you upon the offer if i can't fix it (but i'll pay for your time too - you don't run a charity after all). But i'd like to try replacing the VR1 diode first to see if that cures it. I have replaced most of the other parts (except the resistors) now so i might as well complete the replacement. And if that doesn't fix it, then give up!
 

carl lawrence

Site Supporter
Jul 31, 2011
1,691
658
113
Sandbach
Dom if you want to borrow a working board I will pull the one out off nitro ground shaker and post it to you !! Just PM me your address 👍
 
OP
OP
domlouis

domlouis

Well-Known Member
May 28, 2014
1,040
474
83
Derby
Thanks Carl. Nice offer. I'll pay your postage.
The plan is to replace the diode vr1 first and see if that fixes it.
After that maybe I ought to try your board Carl to see if it is my board that's the problem.
If it is then I can send it to Andy for repair as I will have replaced most components unsuccessfully by then.
If not I'll continue to scratch my head...
 
OP
OP
domlouis

domlouis

Well-Known Member
May 28, 2014
1,040
474
83
Derby
Update: tonight I have replaced the vr1 diode which had arrived in the post this week. Plugged the board back in and .....................................................................
Hurrah! All the displays are back on. Can't believe it. All of them.
So in the end I have replaced transistors, capacitors etc and all it needed was a new diode. Oh well at least that has probably ensured that the board will survive few more years. And on the plus side I have massively increased my soldering skills.

Anyway I have another problem which I had hoped would have been sorted with the higher voltage being available. But it hasn't. If you lock a ball when lock is not lit, the ball is released from the locking hole going back up the playfield. However the mechanism that pushes the ball up is very weak. And unable to release the ball which falls back down in the hole. So it never gets released. Where do I start?
 

stevebm1

Active Member
May 26, 2014
790
171
43
check what coil is on that saucer,it may be the incorrect one,with not enough power,or if you have your back legs cranked right up,the playfield will be very steep and can also cause this problem on vector
 

astyy

Play Flipper Games for Fun and Recreation
Jan 19, 2015
2,193
1,296
113
Basingstoke
Anyway I have another problem which I had hoped would have been sorted with the higher voltage being available. But it hasn't. If you lock a ball when lock is not lit, the ball is released from the locking hole going back up the playfield. However the mechanism that pushes the ball up is very weak. And unable to release the ball which falls back down in the hole. So it never gets released. Where do I start?
That was working then started playing up when the machine was stored here. If memory serves, I released the spring on the 1-way gate to help it kick back through. So the coil and mech is overall correct but as mentioned above probably needs a dismantle, clean, adjust kick out direction.
 
OP
OP
domlouis

domlouis

Well-Known Member
May 28, 2014
1,040
474
83
Derby
Latest update: I had a look and the coil was sticky. Greased the movable part using a small paintbrush and it is back working properly. Good result.
So all in all, vector back working 100%. Quite chuffed.

Just need to start tackling that playfield replacement. Feel that might take a while.
On this subject the paint on the replacement playfield needs a clean and then some protection as it isn't protected at the moment. Any advice on cleaning product and then on a protective layer? Thanks.
Dom
 

stevebm1

Active Member
May 26, 2014
790
171
43
novus and mylar are your best bet,but I believe you can get a full playfield protector from germany,but ive never tried to fit one myself,so not sure if they are a pain in the @rse to fit
 
  • Like
Reactions: domlouis