Piece display PCB discussion

Assembly instructions for the V1 chessboard.
fdastoor
Posts: 44
Joined: Mon Sep 10, 2012 8:49 pm

Re: Piece display PCB discussion

Post by fdastoor »

Tony on Jan 14 in a reply to a message by Sean you asked him to check the voltages across capacitors on the display board. Do I just use a voltmeter to check the voltage across the capacitor - while the display piece is sitting on a board coil that is powered up. What should the voltage be?

I too have a display that will not light up. The diode is oriented correctly there are no visible shorts but I suppose there might be a short UNDER one of the capacitors.

Can you please help me troubleshoot this display piece?

phil
Tony
Site Admin
Posts: 952
Joined: Tue Jul 24, 2012 8:05 pm

Re: Piece display PCB discussion

Post by Tony »

You should see about 50-60V across each capacitor. The usual cause of a dead display is the insulation on the coil wire so check that's connected first. Check all the componets are soldered, sometimes they may look OK but haven't made contact. Is it an engraved PCB piece or the later black resist one?.
fdastoor
Posts: 44
Joined: Mon Sep 10, 2012 8:49 pm

Re: Piece display PCB discussion

Post by fdastoor »

It is the copper engraved pcb. I had removed the enamel from the ends of the copper wire and checked continuity both before and after soldering the wires to the boards.
When you say 50V across the capacitor How do I take the measurement? Do I p;ace the black lead of the voltmeter on the black pole where the board is powered and then the red or positive lead on one end of the capacitor and then the other end?

phil
Tony
Site Admin
Posts: 952
Joined: Tue Jul 24, 2012 8:05 pm

Re: Piece display PCB discussion

Post by Tony »

Both probes on the capacitor, one at each end. Not easy on a tiny SMD part... Use something to stick the piece board in place over the coil or it'll slide all over when you try to take a reading. First easy test though might be between the 2 pins which connect to the nixie, you should see 180+V there unloaded.
fdastoor
Posts: 44
Joined: Mon Sep 10, 2012 8:49 pm

Re: Piece display PCB discussion

Post by fdastoor »

I get 177V across the 2 pins. Next step - check the voltage across capacitors?
Tony
Site Admin
Posts: 952
Joined: Tue Jul 24, 2012 8:05 pm

Re: Piece display PCB discussion

Post by Tony »

Have you tried another nixie?. It sounds like a faulty tube.
fdastoor
Posts: 44
Joined: Mon Sep 10, 2012 8:49 pm

Re: Piece display PCB discussion

Post by fdastoor »

After checking the mounting pins I realised I had appropriate power. I then took a very fine probe and scraped thru all the grooves on the etched copper board. Also under the capacitors as best as I could. Then voila, the nixie started to glow. Must have been a short. Thanks again Tony.
fdastoor
Posts: 44
Joined: Mon Sep 10, 2012 8:49 pm

Re: Piece display PCB discussion

Post by fdastoor »

After a good run have had problems with recent Piece PCB Built. The current one was my fault as I placed one of the transistors and a capacitor in the wrong spot and had to remove them [using ChipQuick]. I replaced the components but something is not right.

1] No power at the pins.

2] Almost no voltage can be measured across the capacitors.

Anything else I can do? Or just remove all components and start all over?
Tony
Site Admin
Posts: 952
Joined: Tue Jul 24, 2012 8:05 pm

Re: Piece display PCB discussion

Post by Tony »

Hopefully my email reply will have helped....
fdastoor
Posts: 44
Joined: Mon Sep 10, 2012 8:49 pm

Re: Piece display PCB discussion

Post by fdastoor »

I did not receive e-mail regards previous post about difficulty with display piece PCB. They are as follows

1] No power at the pins.

2] Almost no voltage can be measured across the capacitors.

Anything else I can do? Or just remove all components and start all over?
Post Reply