Can a newer ZW add on voltmeter be repaired?

I wonder if the meter battery is bad or low. The manual says to charge the battery set one of the handles above 9 volts for a few hours with no engines or cars on the track.

I did what you suggested Gweedo and still the same issue. I must say I am not very happy but then again it is my fault. <grumble>

Any other suggestions?

No If it's not the battery I don't know where to go next.

Hi Jeff,  If the 7 segment displays light at power up, that means the BCD to 7-segment decoder driver IC's are working.  The fault must be at the input stages of the circuit.

Hello Marty,

Here are two pictures with one and the initial power up and then one with no trains running but my accessories are powered up on the b and c channels. Where do I go from here? I appreciate you help on this!

Thanks again,

I'm no help with the gauges, but your garage is looking pretty good

Steve

I am really looking forward to seeing some more of your magic done on it! Thanks!

Dale M. has been thru one of these...forgive me Dale if you don't need any more projects. But maybe if you email him, Jeff, for info on what he thinks about the issues. The most difficult thing about a repair might be availability of the parts.

I thought you said that all of the segments light on power up. I see one segment not lighting in your first power-up photo. It's the same one that isn't lighting on the number "2". My guess is that the display is bad and that if it's all in one piece, it has to be replaced

I suggest you just use it the way it is as I have found the ammeters to not be very good indicators of what is happening on individual tracks.  I have one I have used for over ten years and find that 99 percent of the time, I am only looking at the volt meters.

Just a thought.

Good luck and happy railroading,

Don

True...the ammeter pickups are not isolated as to the 4 individual circuits. BUT, it would drive me nuts to have some part of it broken and the ammeters are at least indicating a change. Just offhand, you could total the readings for some meaningful data.

Carl has it right I think. The segment is out in both pics. This is one of the things I did in my past electronics career. The display itself is likely bad.They cannot be repaired if the readout is a one piece sealed unit.

Rob

Isn't that the same one that works for the old ZWs?

Either way, I'd say carefully crack it open and look for water damage...also see how everything is attached in there. If the single LED readout is bad it should be available...getting to it and replacing it may not be so easy.

I saw one of those at the last train show and the guy said it worked but it was under water for 2 days...passed even at $40 for it.  

Yes Carl has it right.  That segment is out in test mode and use mode.  Transformer output A, the current signal, has no reading.  That may be just a Shunt Resistor.

Looks the same...mount an all. I have both but they are two different part numbers. I wondered what the difference was, but never checked the insides.

As regards the "Likeness" of the two ZW meters:  The "New ZW" meter has a button that is used to "Calibrate" the ZW unit, the meter covers this hole on the ZW, so an extension is provided in the meter to access this button on the  "New ZW"; the "Old ZW" meter has a hole where the button would be, but there is no button, as it is not needed. I do not know if there is any other Electrical differences between the units based on the electronics of the two types of ZW's.  Hope this helps. Dennis M.

Yes, Open the unit and draw a schematic yourself.  I earlier mentioned a shunt resistor for the current signals,  maybe they are using current transformers.  You have to look inside.  

Here are some pictures and some info...

http://www.trainfacts.com/trainfacts/?p=378

Check continuity through the output leads and the current sensing resistors (shunts), the four large black resistors.   You may resolve that one missing current signal.