Elite burn out

[RDS]

... Any reasonable "Security Screwdriver Bit Set ...

 

I bought the 33 piece Duratool set recently.  Part No D00391, available on eBay. 

Less than £5 incl P&P.

[96RAF]

Tri-wing and triangular are different.

 

Tri-wing are like cross point but 3 slotted rather than four and triangular is exactly that.

 

You can get away with using a hex-key for triangular but not for Tri-wing.

 

Rob

[Chrissaf]

The triangular screw heads are "security screws". Designed to try and prevent consumers from taking products apart. Any reasonable "Security Screwdriver Bit Set" (search Google) should provide a special screwdriver bit to fit these security head designs.

.

or alternatively these

[WilliamDavid]

Does Hornby actually try to fix these things.

'Beyond economic repair' seems to be a cop out.

[pidder]

Absolutely... That was the response I got when I returned mine after a failed update. 

[Crossie]

Possibly due to dried out heat transfer paste twixt component and heat sink

Q2 is IRFR024N and Q4 is IRFR9024N although these may be obsolete by now but a web search should bring up the later items if applicable.

Notice Q4 has a lot of solder flooded on its legs.

PCB looks to be damaged but may be recoverable.

To get at the back of the board pull off the knobs, then remove the nut and washer securing the speed encoders.

Next release the white ribbon cable - clamp flips free and cable slips out, then release the plastic clips at mid board each side and it lifts away, although as you have already got the heat sinks off you have obviously got there already.

Rob

Thanks Rob for the info on the chips... I fried mine..  now I have replaced the 2 mofs.. the elite powers up and works will controls trains..  but Q2 starts getting hot with nothing connected so i shut it down after a minute so as not to fry the new Mof..  So obvisouly there is some other component failure causing a high current draw through Q2..   Has anyone more knowledge on this.

cheers

Crossei

[96RAF]

@crossie

I have a duff Elite with exactly the same problem. It gets smoking hot and if left would no doubt fail just like HB’s original reported failure. That one is sitting in the ‘don’t know’ box at present. You may be able to diagnose if a failed component upstream is causing a high current draw on that Q2.

 

Edit: Maybe R26/27 and R76/77, which are on the ground side And linked to current sensing. I also have a note which talks to flooding the ground tab of Q1-4 on the component side. See the Teardown (link below) ... Resistors are likely to be just to left of cap C3, but can’t be sure as my picture is poor focus. Note solder flooding on U4/5

 

I am assuming you have seen the Elite Teardown article by now.

http://www.halton96th.org.uk/page12.html

I must get round to including the Q1-4 details in the parts table rather than in text as presented. That will have to wait until I get back home next month As I don’t have the files and web authoring software with me on holiday.

 

Rob

 

[james_nelmes]

When I google the 8 pin choke L6 & L4, the Farnell component that comes up looks much taller than the original component. Is that ok or have I got the wrong part?

Regards

Jim

[96RAF]

The quoted part data sheet gives these dimensions.

Compare with the installed item.

3032 is the size code.

[james_nelmes]

So I've looked at the faulty elite and L4 and L6 are much smaller than the replacement part (measured about 4mm x 3mm) but I think the suggested part will fit on the pads.

The issue on the elite is there is no power. I have traced this down to what appears to be a 'short' across the power input where the resistance across the 15v in is reading 2.2 ohms which is just plain wrong (compared to my working elite).

I've done some research and these common mode chokes can often fail short circuit as well as open circuit so my theory is that is what has happened to L6. Is that consistent with other failures of these chokes?

Thanks

Jim

[ColinB]

Ok, I haven't read all the responses, so if I repeat something, my apologies. First one I read was Hornby said it was a Display Buffer error, that is absolute rubbish, the display looks to be similar to the ones I have used in the past. Generally you define a display buffer in software, so unless the micro has died I doubt it is that. So I suspect 96RAF is right probably an error with the display itself. The other error is the inductor going short circuit, have you tried removing the inductor to see if the short disappears and if the unit starts working.

[96RAF]

If you remove the inductor you break the downstream circuit, hence it won’t boot at all. The usual ‘bodge’ for a failed choke is to link a by-pass wire across it.

The display fault was years ago Colin. The recent post is about the footprint of the replacement choke part numbers as quoted in my Teardown, which came from the Elite wiring schematic and RS equivalency tables.

[ColinB]

I did wonder about that, seeing as chokes are normally in series in a circuit, so I did find it hard to believe it is causing a short circuit.

[Fishmanoz]

Colin, if my suggestion to lock old threads in Forum Feedback had already been implemented, James wouldn’t have been able to post his simple parts profile question on the end of 3 year old Elite problem and you wouldn’t have spent time trying to solve the old problem.

This further illustrates that it is usually better to raise a new topic to solve a new problem, and give it a good descriptive title. While Jame’s Elite may be burnt out similar to the original OP, that’s not his problem. His problem is the equivalence of parts to fix it. If he’d raised a new topic, he could have said that in the title.

And this is not a criticism of either James or Colin, what I’m criticising is the forum software not locking old threads and using this topic to illustrate why it’s a problem.

Mod note - @Fishy

The case for locking old threads has been put forward to Hornby, along with your reference back hyperlink suggestion.

[ColinB]

I would agree with you on this one. I must admit I didn't look at the date, I just assumed the latest post was on the same issue. Thankfully I didn't spend much time on figuring out the answer to the display issue, I have used a lot of those displays, so not a problem.

Usually I look at the date but there were so many entries that I just read the text. I have never used them but I suspect someone like Lendons is a better bet for fixing old Elite controllers. I suspect either he, or he knows someone that is in to electronics (retired or young), so they are going to spend more time trying fixing the issue probably for not much money.