5V death

Yes, generally first rule is measure and check current when powering a suspect engine. Ideally should be less than 1.5A and taper off. In DCS where the engine just sits there silent should be roughly 0.5-0.8A or so. If it draws no current- that's even worse meaning it burned so badly it's now open circuit. This info comes from the upgrade manual but is just as important when testing any suspect engine. https://mthtrains.com/sites/de...ction/50as15442i.pdf

Second part is, if it passes the current draw startup test, then attempt conventional operation without DCS connected to the track.

Last, since you had it open, check for blown or swollen capacitors and burned smell.

Vernon thanks for your reply.

Vernon I don’t have an easy way to measure the current draw. The battery is in the tender so I haven’t seen the board. I was wondering if this could be anything other than the board. This is the first 5V board to go bad for me. I’ve got my fingers crossed for the others I have.

@GHD posted:

Vernon I don’t have an easy way to measure the current draw.

A worthwhile purchase, useful around any model RR.  The Harbor Freight CEN-TECH 6 Function Mini Clamp Meter

This allows you to measure AC current without breaking any wires, just clamp on one wire to the track or accessory and you can directly read the current.

@GHD posted:

Vernon I don’t have an easy way to measure the current draw. The battery is in the tender so I haven’t seen the board. I was wondering if this could be anything other than the board. This is the first 5V board to go bad for me. I’ve got my fingers crossed for the others I have.

When the 5 volters die, there’s usually no warning, ….the caps can let go just sitting on the shelf, ….you can’t obviously see them, so when you set the engine on the track, nothing,……and it’s curtains, boom boom, out go the lights …..I did have one blow up while running, …..now that’s a sight to see, ……beings a Dreyfuss with the board in the engine, it looked like a boiler explosion,…..all 3 emotions at once, …..scared, mad, & exciting …..the last being only 1.2% …..😉

Pat

@GHD posted:

I took an engine off the shelf that I haven’t run for a long time. It has the 5V board and had a BCR in it. I gave it time to charge. I got no response from the engine. I replaced the BCR with a charged green battery. Still no response from the engine. I assume that the board is dead. Am I missing something? This was using the DCS system.

If a locomotive with a PS2 5V board is placed on the track, whether conventional or DCS, and it will not power up it's dead. No need for further tests. The PS2 5V boards die one of two ways: caps die and there's an open circuit and no response or caps die and there's a short which immediately trips the breaker on your power supply. Either of those happen and there's no need for further tests, the 5V board is dead. 

@Lou1985 posted:

If a locomotive with a PS2 5V board is placed on the track, whether conventional or DCS, and it will not power up it's dead. No need for further tests.

Well, not exactly, though it's a pretty good bet.  I've brought a few back to life, though far more likely that those exhibiting these symptoms are really dead.  It's always good to try them in conventional with a known good battery or BCR to see what's going on.

@Lou1985 posted:

If a locomotive with a PS2 5V board is placed on the track, whether conventional or DCS, and it will not power up it's dead. No need for further tests. The PS2 5V boards die one of two ways: caps die and there's an open circuit and no response or caps die and there's a short which immediately trips the breaker on your power supply. Either of those happen and there's no need for further tests, the 5V board is dead.

Lou, correct me if I’m wrong, but 5 volters have a DNR order stickered on the back side ,…..no??…..😉

Pat

@gunrunnerjohn posted:

Well, not exactly, though it's a pretty good bet.  I've brought a few back to life, though far more likely that those exhibiting these symptoms are really dead.  It's always good to try them in conventional with a known good battery or BCR to see what's going on.

99% of the time it's pointless. Locomotive with a 5V board won't power up or instantly shorts? Dead. Install a PS32 board, TMCC, reverse unit, or rectifier and move on.

@harmonyards posted:

Lou, correct me if I’m wrong, but 5 volters have a DNR order stickered on the back side ,…..no??…..😉

Pat

5V boards aren't worth bothering with beyond ripping them out and throwing them in the trash when they die. So yes, DNR when you see no charge port or a round charge port on the bottom of the locomotive.

Well, if it instantly shorts, and you've verified it's the board, maybe.  However, I've seen shorts in the trucks and interior wiring as well.  Same with no power, sometimes it's not the board.

I don't really care how you deal with them, but I choose not to toss a good board, only to find that a wire came loose from a connector.

Only sure way to see if it's the board, is by taking it out and checked in a PS2 test fixture.

@Joe Allen posted:

Only sure way to see if it's the board, is by taking it out and checked in a PS2 test fixture.

Well, that's exactly what I do with any that fail.  I have 5V boards that have worked perfectly for years, and others that have crapped out on the shelf.  I'm not tossing in the towel until the floor is wet.

Thanks for the discussion John. That’s what I was hoping for. I don’t run this engine and I guess that’s obvious as it was on the shelf for a long time. If I decide to get it fixed the first thing I’ll do is get it to someone that can check the board with the right equipment. Thanks for the suggestion for the meter. I need one of those as all my power comes from ZW’s. I hard wired my meters into my layout when I first started 20 years ago. Yes I have a lot of 10 amp fast acting fuses.

If you get that far, I can toss the board on the test set and see if it's got a chance of living on.

GHD I can tell you from personal experience John is good and a great person to work with I have made the 3 hour drive each several times for him to fix/help me out.

The cap is not always part of the problem. There are PV diodes that short, power FET for controlling the board that short. Processors that just die.

Plenty of late revision boards that do not have the suspect bad caps that die on their own and the caps are perfectly fine.  The whole dead battery is another myth.  Plenty of those trains I see with the original white battery and still running fine.  Even PS-1  G

@GGG posted:

The cap is not always part of the problem. There are PV diodes that short, power FET for controlling the board that short. Processors that just die.

Plenty of late revision boards that do not have the suspect bad caps that die on their own and the caps are perfectly fine.  The whole dead battery is another myth.  Plenty of those trains I see with the original white battery and still running fine.  Even PS-1  G

@GGG,

A dead battery though isn't a myth if it's really dead.  Is what you're saying that often white batteries are not really dead and that we just assume that they are?  How often have you found good ones?

The white batteries in everything I've bought in the last five years have indeed been dead.  PS1 and PS2.

Connected to the MTH wall wart charger for charging.  Read low voltage after 24 hrs of this kind of charging.

Green ones have been fine.

Mike

I suspect George was saying that a dead battery doesn't automatically kill the board.