I really dunno, Arnold but I would guess that MTH would have skipped the fan and saved the expense if it was not necessary for the long run.

I'd get it fixed if it were mine

Thanks, John.

One more thing about the old Z4000. Whenever there's a derailment, the red light goes on and everything shuts down immediately so I guess the circuit breaker is fine.

I kickstart mine with a toothpick through the rear vent when I turn it on...that is when I remember.

John's comment is almost verbatim what I was going to write.  However, Bob is like you in that the Z4000 still provides the necessary output.  If you put it under heavy load (draw more amps) then you could have an overheating problem leading to fire or an internal short circuit.  Since you refer to yourself as an amateur, I would take it to an MTH service technician to repair.  I haven't had mine open to know if the fan plugs into a board or if the wires are soldered.  Since you now have the new Z4000, it is an excellent time to get some maintenance done on the original, and it should outlive you and me.

If its actually 25 years old its a first edition Z4000. The boards may NLA or if available very expensive. Good idea to change the fan before you lose a board. Removing the 7 allen screws from the underside will let you remove the top cover.  You should be able to see the fan after the cover is removed. I don't recall if the wires are soldered to a board or go through connectors. In any event you could just cut the wires off the old fan and splice them to the new fan without having to mess with a board. Any competent electronic tech should be able to do this. No need for an MTH guy to do it.

Pete

Thanks guys for your very helpful advice. I will mull it over and then make my decision. Arnold

@taycotrains posted:

I kickstart mine with a toothpick through the rear vent when I turn it on...that is when I remember.

Bob, I tried your idea of kickstarting my Z4000 fan with a toothpick, but it did not work.  I love Rube Goldberg fixes like that.

I also thought of another possible Rube Goldberg fix: having a fan blow in the direction of the transformer where the vent and transformer fan are.

I certainly have no complaints about this transformer which has given me 25 years of excellent service and continues to do so. 

Arnold,

I replaced my fan a while back on my first issue Z4000 because I thought it was too loud (did not make a difference). The fan is connected with a plug but it took some wrangling to get in place.

Looking at the picture you can see the white plug on the lower right. If I can find the old fan your welcome to it. 

Frank

Arnold,

I did find the fan unit but I was thinking maybe your connection plug is loose? The fan is yours if you want it.

Frank

It's there to keep the new age electronics cool when pushed hard.

It just a standard computer fan. I've had old PlayStation 3 fans die often, usually in the drive circuit.... good luck with that repair. They really need it too, crashing from heat protection circuits.   I got tired of disassembling and mounting them.   My solution is a slightly bigger computer fan run on a wallwart, and set in right in front of the unit's vents(or cover off and set right on the fan housing itself for one really hot runner (modified processing/a hot rod)

If it keeps those cool enough to stay on, I think it could easily vent a transformer without any apparent excess heat issues to begin with. 

I wouldn't ignore it though. As noted, it's a lot of wasted money by MTH for not really being needed. 

The price is likely well under $20 for a good generic computer fan and wallwart (12v dc. An ac fan can be had too. and some of those can really move some CFM and normally last longer in my experience too.

The first gen Z4k fans were crap, I had two fail within a few months. The mth replacement part is much better. 2 pin plug, simple plug n play stuff. Or you can find a generic replacement at any computer parts store.

For day to day light running you probly wouldn't notice not having a fan for say an hour or so at a time. But that doesn't make it the right thing to do. You should replace it. It's too bad mth didn't design the fan with a pwm controller, to increase speed at higher loads. Like computers have been using for decades now. Or at least a thermostatic switch so it would stay off until needed. But that would have cost a few cents more of course.

Years ago I did some full load (400 watt) output testing of an early z4k just for fun. I found that after a few minutes at full load the rise in air temp was about 20 deg F, and stable, as I recall. So at heavy loadings the fan definitely does something. But full load represents both track outputs at 18v and 10 amps each, plus another 40 watts loading on the accessory outputs. This is not likely a loading that would be sustained on a home layout for any length of time, especially these days with mostly led lit passenger cars. YMMV!

Rod

When I buy replacement fans I usually go to Digikey, search on DC fans, select the size, and voltage but also check off ball bearing type. These will last longer than plain bearing which cost less. Some give the db noise level. Noise and CFMs usually go hand in hand so more air means a noisier fan.

Pete

Did the original fan use a bushing or ball bearing ?

Generally speaking, an equivalent spec ball-bearing fan should be quieter. 

Looks like Norton beat me to it ! 

Arnold - co-incidentally the fan in my Z-4000 quit working yesterday.... which bummed me out   I'm delighted to see your thread with so many helpful replies.   I hope your resolve your issue soon.  Got to keep your railroad running!

Here is my scenario:  Yesterday afternoon I decided to go upstairs to my train room.  Since I do not have central air conditioning I use a window ac unit ( a 20 year old unit which does not put out cool like it used to ... ( soon to be replaced ) ... so it does take a while to cool the room down.   Of course the temperatures outdoors yesterday were in the mid 90's and upon entering, the train room the temp certainly felt about the same if not more, due to the door being closed.  

 I fired up the ac unit and the layout simultaneously.   i was running trains on the two lower main lines which are controlled by the Z -4000.  After a minute or two of operation, the locomotives of each main line began erratically  blowing their horns ( as if " little person" engineers were inside LOL ).   One line was running at 14 volts and the other 17 volts, both powering MTH engines.  ( There are no accessories running off the other two channels.)   I had never experienced this behavior from this Z-4000 before ( and it is an earlier model Z-4000 ).   I checked wire connection to the transformer to  make sure no wires were touching between negative or positive binding posts.  There were not.  I next turned off the ac unit so I could listen to the Z-4000 and this is when I noticed the fan was not working. I also checked the circuit breakers but they had not been tripped.  After this brief inspection and reading the z-4000 Owner's Manual ( which was of no help),  I turned the ac unit back on and let the room cool a bit more before turning the Z-4000 on again.   Once I began running the same locomotives again at the same voltage levels,  the erratic horn blowing ceased to exist.  I'm not a technical wizard by any stretch of the imagination, however, my hypothesis is that  the train room's exorbitant temperature  combined with extra heat produced in the first couple minutes of operation caused the fan to fail.  It's quite possible the fan was on it's last legs anyway.  The fan was replaced by MTH about 5 years ago.   Any of you guys have any thoughts about this particular occurrence?  

I allowed trains to run at same voltage levels ( 14 & 17 v ) for about 5 minutes before I shut them down, turning off the Z-4000.   After being shut down for about 15 minutes, I turned the Z -4000 back on and ran trains another 5 minutes.  There was no erratic horn blowing during either 5 minute interval.   I didn't want to take any chances of overheating the Z-4000 so I haven't run trains since.   I will probably run them at 5 - 10 minute intervals until I can get the Z to a repair shop.  

I will probably take to an MTH repair person rather than try to install a new fan myself.  Thanks to all of you who posted information and good to know that computer fans can to the job.  I'm so grateful for the OGR Forum and all of you folks who post.   With MTH closing next year, it's good to know there are other ways to solve issues with their products.   

Btw - This Z-4000 has given me years of great service.  

If you run high current post war engines or outside shows, it might be necessary. Otherwise it’s noisy and probably not needed operating today’s low I items in an AC environment.

@franktrain posted:

Arnold,

I did find the fan unit but I was thinking maybe your connection plug is loose? The fan is yours if you want it.

Frank

 

I appreciate your very generous offer, Frank, but I will send mine to an MTH expert to repair and service it. In the meantime, I bought another brand new Z4000 because I want to have 2 of them hooked up to the layout and the 3rd (the old one after its serviced) will be my spare for the long term. Arnold

That plan works, Arnold!  Buy what you think you may need while you are still working, and you should have a happy retirement when the time comes!! 

@Mark Boyce posted:

That plan works, Arnold!  Buy what you think you may need while you are still working, and you should have a happy retirement when the time comes!! 

Mark, you are a fountain of kindness and compassion, with a kind word for everyone. IMO, that is a very good way to be. Arnold

@Arnold D. Cribari posted:

Mark, you are a fountain of kindness and compassion, with a kind word for everyone. IMO, that is a very good way to be. Arnold

Thank you, Arnold.  I just try to help.

That brings up an interesting side topic for those of us that use the Z4K to power our layouts.

With MTH potentially closing up shop, would it be wise to invest in a second Z4k now as a back-up for the future in the event the primary one should fail in the years to come ?

Seems like that is what Arnold has essentially done.

Its my understanding the folks who have taken over DCS will continue to offer the Z4000. Its a good transformer. For me the ability to reprogram MTH engines is its primary attraction. Otherwise I would just go with a basic transformer and multiple fast breakers like the DCC PSX-AC.

Pete

@Richie C. posted:

That brings up an interesting side topic for those of us that use the Z4K to power our layouts.

With MTH potentially closing up shop, would it be wise to invest in a second Z4k now as a back-up for the future in the event the primary one should fail in the years to come ?

Seems like that is what Arnold has essentially done.

Exactly.

Arnold

@Norton posted:

Its my understanding the folks who have taken over DCS will continue to offer the Z4000. .......................................................

Pete

Interesting Pete - who did you hear this from?

Any other insider tidbits you can share?

Actually I believe a forum member is one of principals taking over DCS and has mentioned it here. They plan to continue DCS and even make improvements.

https://ogrforum.com/...proto-sound-lives-on

Pete

Arnold, you may be even happier than you thought you were to have a back-up!  Regarding the future of the Z-4000...

The following announcement was included in yesterday's MTH weekly email to their dealers.  I was surprised that someone hasn't posted this here on the Forum yet.  I highlighted the reason why MTH claims it will no longer be produced.

Uh oh...or maybe, "OH NO, say it ain't so!!"  I love the Z-4000!  So now I have to decide if I should purchase another one (I already own two...this would be my 3rd) to put away for future back-up use...or stay clear of it altogether.  Hmmm...

Z-4000 Transformer To Be Discontinued in 2021, Last Production Run This Fall

July 21, 2020 - M.T.H. Electric Trains' Z-4000 transformer will be produced for the last time this Fall with delivery slated for late 2020/early 2021. Future productions of the venerable transformer will not be possible due to a discontinuation of the unit's microprocessor and lack of suitable replacement in the secondary electronics marketplace.

Conventional or Command Control operators have chosen the Z-4000 transformer as their go-to transformer for nearly 20 years. The industry's most powerful UL listed transformer, the Z-4000 delivers 400 watts of continuous power at just over a $1.00 per watt. There simply is no better, affordable power supply for AC model railroads than the M.T.H. Z-4000.

Equipped with two smooth-operating, wide-range 10amp throttles to let you power two different tracks, the Z-4000 lays down up to 22 volts AC onto each track it controls. Bright LED displays monitor voltage and amperage outputs for each channel while the fast-acting resettable circuit breakers protect your trains and accessories from damaging voltage spikes.

A built-in cooling fan keeps the unit's internal circuits running at max capacity for hours of continuous operation making the Z-4000 a great choice for club layouts, public displays, and home layouts alike. Two separate accessory outputs are included making it easy to provide 10 - 14 volts continuous AC output for trackside accessories, switches, lighting, and more.

Simply put, a single Z-4000 will power a lot of layout!

Now is the time to order the Z-4000 (Item No. 40-4000) and avoid missing out on the last run. Direct accounts can order via the M.T.H. Dealer Portal by selecting the 2020 Volume 2 Order Form while indirect accounts should see their favorite M.T.H. Authorized Distributor.

Yikes - what a great time for some Forum sponsors to put on a sale 

@Richie C. posted:

Yikes - what a great time for some Forum sponsors to put on a sale 

You want to buy something that no longer can be supported!?  And I have been a BIG MTH supporter since the early 90's and now will not buy anything MTH beyond rolling stock!

Ron

I spoke to Midge of MTH today, and she told me MTH no longer has the Z4000 fan, so I probably need to get a computer fan from a place like DigiKey.

Reviewing this thread, it looks like the specifications for the fan include 12 volts, 0.15 amps, and it's a rotary DC brushless fan, although an AC fan can also work.

Do you agree?

Also, what is the correct size (diameter) of the fan, and what is the wattage?

Arnold

Have you tried blowing some "canned air" against the fan to get it spinning free? (IIRC it blows out so a taped on the case fan should pull hot air out.)

Arnold; Here is the fan MTH sold as a replacement. The 12vdc 1.2 watts suggests its 0.1 amp. That's all you need. You can get more powerful fans but they will be noisy. Fan size is 60 x 60 x 15 mm. You must use 12 vdc; not ac. A computer parts house will be able to sell you a generic replacement that will work fine.

Rod

Arnold,

The big A has a ball bearing fan that looks to be the correct size and electrical specs for $10 and is claimed to be good for 50,000 hours of usage which might outlast us all.

Just look at the plug and make sure it is the right fit for the Z.

Amazon.com: Wathai DC Exhaust Cooler Fan 60mm x 60mm x 15mm 12V 2Pin Brushless Cooling Fan: Computers & Accessories

The specs that really count are the size. Outside edge and thickness plus 12v DC. If you go to the digikey site you will see many with those specs. Then look for one with ball bearings. The will be slightly more expensive but last much longer. Digikey will also list CFM rating (airflow) plus sound level in db. As Rod points out more airflow will usually mean higher db rating. Power rating in watts is less important. All will be draw little enough power that the transformer will handle any of them.

edit, I see Richie is also a fan of ball bearings.

Pete

I helped a friend of mine replace his with a 12 vdc, 1.7 watts computer fan we lifted from an old machine. This works out to almost .15 amps like the original fan.  I guess it really doesn't matter that much, since, as Rod points out above, they offered him a lower watt replacement. It was a very easy swap out, Arnold so you should have no problems doing it, but don't wait another year! Get 'er done!