Hornby Elite output

[Dukedog.]

Hi All I have a Elite with the following problems

track output voltage 9.9vac

program output volts 0.231vac

boost 14.10vac

Aux output 15.22vdc

is this a typical fault

can any one point me in the right direction as to what might be wrong.

thank you

[96RAF]

Track output should be around 15vAC but the value seen on a multimeter depends on the sampling rate.

An RRAMP meter will give an accurate value.

Prog output is only present during actual programming bursts and usually unreadable.

[Rog RJ]

@dukedog

What problem are you having. The voltages on their own don't tell us too much.

[Dukedog.]

Thanks for the reply 96RAF just been and checked the output of my Select with the same multi meter and get 14.86vac so i assume the meter is OK.

thanks again

 

[Dukedog.]

Ok the under lying fault is the loco moves as soon as it is on the track but only stutters there is no control from the dials the same loco is fine with the select controller

[Rog RJ]

Do other locos work ok on the Elite?

[Dukedog.]

No but that said I have only tried one other and just the same, both work OK with the select.

[ColinB]

The Elite uses a separate power supply to power it, it could be that. It could be breaking down on high loads, so there is enough power to drive the display but not enough to drive the locos at full speed.

[Dukedog.]

I am using the same 4amp power brick/supply to power ether the Elite or the Select and voltage checks done with no load on the track

[P-Henny]

Dukedog,

The Elite might possibly have gone into Address Zero mode or some other form of corruption. I suggest you follow the Elite manual instructions regarding performing a factory reset and then test again.

[Dukedog.]

ok thank you will try factory reset

[Dukedog.]

factory reset completed no change

[96RAF]

No one has asked yet but what firmware revision are you running, not that it should affect the output at all. Current version is v1.45.

Try a self test by powering up with the Loco button held down until you see Hornby on screen then release. The screen will populate all pixels and do a memory test reporting pass or fail. You can then press each button and twist both knobs to check they all react. To reset from this mode simply reboot the Elite.

All signs so far unfortunately point to a Track output fault, possibly common mode choke L4 which can be linked past with shorting wires to prove if it is throttling the Track output. Top left of this picture...

[ColinB]

Ok, reading you post again those voltages are reasonable. The programing output only pulses when you program something so unless you are using a peak hold meter, that voltage means nothing. Even the track output means not a lot as it is a sophisticated waveform not easy measure with the multimeter on AC. It could be that the drive to track has issues, if so I doubt there is a lot you can do. As to the Select and Elite working on the same power supply, I doubt the Select draws anywhere near the current of an Elite. Perhaps you have lost an return wire somewhere inside the unit by it becoming detached.

[Fishmanoz]

Noting the last posts from Rob and Colin occurred almost simultaneously, they would each have been unaware of the other’s content when they posted.

Even so, a couple of observations on Colin’s:

• while track output measured with any particular multimeter can be quite unreliable and variable, I think he’s missed Dd’s comparison test on Select and Elite with the same meter? That is significant
• while the Elite can draw more current from the PS than the Select, it will not be doing so if all that you have running with either is the single loco mentioned. Differences in standing current from the devices themselves will be minimal and the loco load the same (assuming only the one loco on the track in each case)

Given the above, I think Colin’s hypotheses yet to be proven and I’d be trying Rob’s self test and L4 short-out first.

[ColinB]

I am not so sure about the difference in current draw will be insignificant the displays are different and I imagine the Elite has far more electronics in it, either way it sounds like a there is very little the person who started the post originally, can fix. I suspect a return to Hornby or some else who can fix it.

[96RAF]

This is a typical common mode choke and the red lines show how to short across each element. Do not short top to bottom or you may make smoke.

For how to access the Elite inside please see my Teardown here http://www.halton96th.org.uk/page12.html

[Dukedog.]

thats great thank you all soldering iron on as we speak hope to report back later today

[Dukedog.]

Ok report back time

The self test came back as a pass and all buttons and knobs fully working.

The L4 choke linked and no difference output voltage still 9.9 ish

[96RAF]

Passed to higher authority for comment.

[Dukedog.]

Thank you 96RAF

[96RAF]

OK - time to get out a multimeter and do spot checks in various places on the motherboard.

A quick check is to bypass the PTC (self resetting fuse) F2 (top right of previous picture), which protects the circuits from the main DC in, past common mode choke L6. The circuit at that point should be 15vDC and it then feeds a pair of voltage regulators that output 12vDC (U4) and 5vDC (U5) to feed other circuits, so you should see these regulated voltages on their pin 3 with respect to ground (their pin 2). If low voltage is seen both sides of F2 then suspect L6, try shorting that out as before.

The danger of bypassing a fuse is you bypass protection and you can damage other components.

PTC F1 protects the Aux output and F3 the Boost output in case you wondered.

If you are getting 15v into the main Track generation circuits then it is likely that the driver mosfets are at fault, given the self test was passed.

I hope this helps.

[Dukedog.]

Thank you 96RAF

ok I have 15.2VDC both sides of L6

On U4 as looked at in the picture the middle leg being ground top leg is at 15Vdc and bottom leg at 12VDC

On U5 again middle leg ground the left leg is at 11.76VDC and the right leg at 5.04VDC

thank you

[Dukedog.]

96RAF just looked at Q4 middle leg at ground top leg at 13.1VDC and bottom leg at 11.6VDC

Q2middle leg ground top leg -2VDC bottom leg .25VDC

so do I assume that Q2 needs replacement?

Thanks again for all you help

[Dukedog.]

just looking at RS and Q2 and Q4 discontinued