MTH QSI ac buzz

[Anonymous]

I just returned from the local shop where I saw a TRO standard gauge 4-4-4 electric loco that is absolutely beautiful!

After helping put a fresh battery in it we gave it a test run. Operation was normal except for a 60 cycle buzz from the speaker. Turning the volume pot full CCW did not eliminate the buzz. Turning the Z1000 off eliminated the buzz and a normal shutdown occurred.

Anyone have any info on this problem? Since there is no MTH warranty on this QS1 consignment loco I hesitate to assemble a nice standard gauge set with a potentionally defective loco. Everything that came in on consignment looks mint in appearance.

Thanks for any help.

Tony

[ChiefEagles]

There is a guy that goes by northern1. If I am not mistaken he is a QSI sales person or was. He is very knowledgable on QSI. Have not seen him around here lately. Might try posting this on Model Train Journal forum. I think he visits there. http://modeltrainjournal.com/phpBB2/viewforum.php?f=2&sid=3e6c2e2fe712a12cd91565a7602af541

[Anonymous]

tonyh,

The problem is usually caused by the voltage regulator on the lower DCRU board. The regulator can be replaced if you're handy with a soldering gun.

There are many of these boards available since the PS2 upgrade kit has replaced them. You can probably buy a used one for about $25-$30.

Hope this helps,

*** Teal

[Anonymous]

Tony,

It may also be the wave form of the Z1000 that is causing the buzz. You might try it with a Z4000 or a post war (not a modern) ZW.