Loksound 6 pin V4 burn out!

[boxbrownie]

My son has just attempted to fit this sound chip into his GF 108 with a sugar cube speaker, unfortunately as soon as it was fitted he experienced jerky movement and could not get the sound to turn on, after a few minutes of button pressing and attempting to get the thing moving smoothly he ntoiced that the chip was too hot to handle and in fact on close inspection a part of the shrink wrap has melted away!

 

Has anyone else had this happen on a V4 chip? We will of course be sending it back to the supplier after the easter break, I am just interested to hear if any other modellers have had problems with these chips.

 

The model of course runs perfectly with analogue connected, so not a GF circuit board problem we assume.

[Lady_Ava_Hay]

It is becoming evident that the V4 Loksound Micro seems to be experiencing some difficulties as you describe. My only proviso is the 'sugar cube speaker' that you describe. Is that a standard speaker for ESU? What ohm rating is it? Did you buy it with the sound chip? Have you checked all the wiring to ensure that there are no stray wires or pins touching anything? Could you show us a photo of the decoder's wiring or is it wired to a plug in a socket?

 

I will leave the experts to inform as to what these components actually do on this chip which may give some clues as to the nature of the problem, but they are seriously charcoaled and this chip would appear ruined. You can check that by addressing it on the programming track and reporting what the command station says. It may well take CV commands which will again help to pinpoint the problem.

[boxbrownie]

The chip is hard wired as standard to the 6 pin plug, so has not been connected wrongly. Also it uses a 8 ohm speaker bought at the same time as the decoder (at the NEC show) so is also the correct speaker, in fact my son first test ran the chip with the original speaker still connected with the same fault showing, he wondered if it was the speaker at fault and changed it for the sugar cube speaker but to no avail, still no sound and jerky running.

 

It really is frustrating for him as he recently moved to Brighton and had to leave his 4mm layout here at home so is attempting to build a small 2mm layout comprising mainly of just the 108 as running stock, this has taken the wind from his sails really.

[Steven B]

Does the 108 work OK with a standard decoder? The metal strips that hang down from the PCB can touch the chassis if you're not careful. On DCC you're just shorting out a couple of components on the PCB and no harm is done. With a decoder fitted you're connecting the track feed to the motor supply which isn't a good combination!

 

I've had a couple of LokSound Mico v4's go pop whilst testing them on the ESU decoder tester - I've no idea why. I was using the original 6 pin socket and supplied speaker. All I did out of the ordinary was to connect the additional function wires to test them with the LEDs on the decoder tester.

 

Fortunatly the shop took them back and sold me new ones at a much reduced price which, touch wood, appear to be OK. I wonder if there's s duff batch of these decoders?

 

Hopefully you'll get your decoder replaced - I fitted my class 101 with sound on Friday and it sounds great - LokSound Micro v4 with a pair of 8 ohm sugar cube speakers (wired in parallel) mounted where the seating went. Sounds much better than the using a 13mm speaker in the mounting Farish provide.

 

Happy modelling.

 

Steven B.

[boxbrownie]

Did not try it with a standard decoder, but we tried the Loksound decoder plugged in and "hanging free" from the chassis so no possibilty at all of a short or chassis touch condition, I think it appears as you found out that there is indeed a faulty batch of micro decoders.

[Nigelcliffe]

David, I think you misunderstand the shorting issue.

 

If you look carefully at the side of a Farish chassis without decoder, there are two metal prongs which descend from the PCB to the motor brushes. In a few Farish models these prongs can be mis-aligned or lacking enough insulation material and will touch the chassis block material. With DC running this is not a problem, all that has happened is a direct path from pickups (via chassis metal) to motor brushes. But with DCC, this is fatal to decoders as it has shorted pickup wires to motor output.

Further, whilst the short may appear to be absent with body removed, the act of refitting the body can cause some small movements of the PCB or flexing in the Farish chassis and then create the short circuit. (I've seen this, it took hours to diagnose!).

I now fit some thin tape through the slot where these prongs hang to protect against shorts if I'm not replacing the entire PCB.

 

That is not to rule out a faulty decoder; I've had a faulty V4 Micro (different fault) which has been replaced.

 

- Nigel

[boxbrownie]

Aha.....I understand what you mean Nigel, I shall take a very close look at the standard chassis tonight and check with a meter if there is any shorts between chassis and pickup/prongs.

 

Thanks for that info.

[boxbrownie]

Nigel, no shorting....in actual fact it appears GF have acknowledged the fact it could happen and now insulate the prong with a sleeve of plastic material.

 

I guess it is a case of bad decoder.......bummer!

[Nigelcliffe]

The prong has always been insulated by Farish, but it could still be bent in production, insulation a bit short, or otherwise problematic. I can't make out how the prong is touching the motor brush in the photo, or if there is a short behind the brush.

 

- Nigel

[boxbrownie]

OK, well I tested for shorting between CB and the chassis and there was no pathway so I guess the insulation is doing its job this time.

[marist way]

I recently had a Loksound chip fitted to a NRM Flying Scotsman (Hornby).The speaker had to be fitted in the tender. However after only about 20 minutes use the SOUND FAILED and then the Loco stopped altogether. Turns out the whole lot is now Code 225 (255) which means it is dead. £125 for 20 minutes !!!!!!!!!!

Anyone any ideas or had the same experience.

I had the fitting done by a very experienced guy in my local model shop.

[Marty Mc]

Hi

 

My experience is generally those fairly new to DCC make simple mistakes. It happens and it is part of the learning curve.

 

With locos that have failed it is down mainly to one simple thing, when you put the body on thinking you have it well insulated you end up with a partial short. Now Im not saying that is the case here but wire gets compressed, solder points come in contact with the body because when you soldered their was a sharp point on the solder and it cut through the insulation.

 

You are adding sound to a n gauge loco using the manufacturers PCB something I would never consider as you leave yourself open to many problems, I would suggest hard wiring.

 

If I have a failure I assume 99.99% of the time it is down to my workmanship not the manufacturers of decoders.

 

Anyway I hope you get your problem sorted.

 

Martin

[boxbrownie]

Hi

 

My experience is generally those fairly new to DCC make simple mistakes. It happens and it is part of the learning curve.

 

With locos that have failed it is down mainly to one simple thing, when you put the body on thinking you have it well insulated you end up with a partial short. Now Im not saying that is the case here but wire gets compressed, solder points come in contact with the body because when you soldered their was a sharp point on the solder and it cut through the insulation.

 

You are adding sound to a n gauge loco using the manufacturers PCB something I would never consider as you leave yourself open to many problems, I would suggest hard wiring.

 

If I have a failure I assume 99.99% of the time it is down to my workmanship not the manufacturers of decoders.

 

Anyway I hope you get your problem sorted.

 

Martin

 

Marty, this decoder was plugged into the onboard socket and the chassis was on the rollers with the speaker resting away from the unit, no possibility of a short and any other fault condition induced by fat fingers.

 

This really does look like a case of equipment failure.............it happens to the best manufacturers, and would appear the Loksound have a bit of a problem with the Micro V4 according to other threads.

[boxbrownie]

All sorted now, South West Digital swapped it out for a replacement without question........me thinks there might be an aknowledged fault on these little blighters!