Lionel Legacy GP-7 marker boards melting and sound issues

Since you mentioned Z4000, and the lights (number boards) melting, did you do something like raise the Z4000 handle to max- around 21-22V on the track, meanwhile Lionel manuals warn and as a rule don't go above 18-19V maximum????

Easily explains them getting super hot.

I usually keep the throttle at 17V being cautious with the electronics (and always watching the amp meter too)

The high pitch sound is there even 12-15V when loco powered off.

Thanks for the suggestion!

I'd change the number boards to be lit using LED's, then if the numbers are screwed up, buy a pair of these and just remove the existing numbers and replace them with the correct ones.  The original number boards for your engine are not available, so you have to ad-lib.

Honestly sorry you are having problems.

Being a 6-28xxxx series engine is early legacy, modular, meaning the modular style of boards. But to check and know that-just look at the parts listing and diagram https://www.lionelsupport.com/...P7-Diesel-21-6-28361

Right off the bat, a few things- this has the smoke regulator which could fail- and that could be feeding the smoke fan motor- which could be one source of the noise. But catch22 "AC REGULATOR (S03 CODE) /OBSOLETE "

Otherwise, i would begin to suspect the railsounds power board, since it's job is to make and regulate clean DC 5V power for the sound card, and it could be failing and thus another possible source.

Lionel parts sale is coming up,

@Vernon Barry posted:

Lionel parts sale is coming up,

cs-6208361116-p

LIGHTING BOARD (LONG HOOD) GP-7

23

$12.50

and

cs-6208361117-p

LIGHTING BOARD (SHORT HOOD) GP-7

24

$12.50

I doubt there's anything wrong with the lighting boards, the problem is the incandescent bulbs get too hot and melt the number boards, it's a fairly common issue.  That's why the suggestion to convert to LED's for the number boards.

@gunrunnerjohn posted:

I doubt there's anything wrong with the lighting boards, the problem is the incandescent bulbs get too hot and melt the number boards, it's a fairly common issue.  That's why the suggestion to convert to LED's for the number boards.

As GRJ says, this is a pretty common issue. I recall that melting number boards because of this were a particular issue with the Lionel no. 14536 Santa Fe F3, Lionel's first Santa Fe scale F unit, when it came out way back in 2002. Later issues of the engine corrected this. The OP's engine was from 2011, so it would seem prudent to examine any engine from this era (at least) and move the bulbs back from the number boards if they appear too close (if a person doesn't want to go through installation of LED replacements). Those little bulbs can generate a lot of heat. I almost burned my fingers once handling some grain of wheat cab illumination bulbs on an F3!

I'd certainly move them back if they're too close, no argument there!   However, the real fix is to generate less heat, an LED with a 1K resistor in place of the bulb is the ticket.  I use diffused LED's that spread the light better than the clear ones.