Hornby R2648X Class 56 DCC Chipped?

[Damo666]

I bought a Hornby Class 56 from a bricks & mortar auction house some time ago, marketed as DCC Ready.

 

Model R2648X, 56059 in EWS.

 

Ran it on the rolling road at the weekend and it runs smoothly, so took off the body to install a DCC chip and found this.

 

Can anyone confirm if this is an 8 pin DCC Chip Decoder and not some convoluted blanking plate please?

Did a search on ModelRail Database https://www.modelraildatabase.com/locomotives/details/1930/ but the ‘X’ version didn’t come up with any search results.

 

And just as a reminder for myself, as I keep getting confused on this:

Can you run a DCC chipped loco on DC without damaging the loco motor? (If this is correct, then this explains why my Loco ran on the rolling road without damage or unintended smoke)

Can you run a non chipped loco on DCC without damaging the loco motor?

 

Thanks

 

Edited March 13, 2023 by Damo666
Completed missing sentence, Corrected nomenclature

[WIMorrison]

What value do you get in CV8 when you read it? That will identify the make of the decoder, if not the actual decoder.

[melmerby]

That's a Hornby R8249 decoder. The bog standard one.

 

You can run a DCC equipped loco on DC if the correct bit is set in the decoder, not ideal but it does work.

You should not run a DC loco on DCC without a decoder. Theoretically there is an address zero mode on some DCC systems which allow a DC loco to run on DCC but it is not recommended and is not good for the motor.

Edited March 13, 2023 by melmerby
banana fingers

[PeterStiles]

The model number "Model R2648X" has the "X" on the end. This normally means "DCC Fitted" in Hornby's world.

 

Looks like a DCC chip; the model number is that of a DCC fitted. Consider it a bargain. Or not if you don't like the chip...

[WIMorrison]

Why do people call it a 'chip' - the pictures show that there are seven chips on the visible side of the decoder, and possibly more underneath. 

[PeterStiles]

because we're too lazy to type "deco..."

[NIK]

Hi,

 

Strictly, chip is reference to an integrated circuit (a circuit on a semiconductor substrate with multiple semiconductor structures). I can see 7 ICs across the two sides of the PCB. The other packages are single diodes, resistors and capacitors.

 

With DCC decoders in short supply and at high cost you seem to have got your self a bonus.

The R8249 retails for £26.75 at the moment from Hornby.

Note that the R8249 is fairly simple and that its continuous current rating is at the low end being only 0.5 Amps.

 

Under some circumstances some OO locos can draw more than that. I tried a R8249 in a OO Heljan Class 33 and it only ran for a minute and then the loco went to and stayed at a slow crawl as the decoder had overheated.

 

Do you have a meter for measuring the DC current a loco draws when running on DC?. This can be useful for selecting decoders that will suit a particular loco.

 

Regards

 

Nik

[andyman7]

The X suffix models (including R2648X) are non-sound DCC Decoder fitted and use the R8249 installed in the 8 pin socket, factory fitted. Auction houses are not always expert and they clearly did not understand this when doing the description, as with all conventional auctions it is 'caveat emptor/buyer beware'. In this case it works in your favour, even if you want to change the decoder.

 

[melmerby]

3 hours ago, WIMorrison said:

Why do people call it a 'chip' - the pictures show that there are seven chips on the visible side of the decoder, and possibly more underneath. 

Hi Iain I think you will find most are transistor arrays.

The large one with a white splash is the PIC

 

(both sides are shown)

 

EDIT

Deciphering SMDs seems to be a dark art as often several different devices can have the same code.

Edited March 13, 2023 by melmerby

[WIMorrison]

Thanks Keith, I had missed the fact that both sides are shown 😒, doesn't alter the statement that it isn't just a 'chip' providing the control, it is a complex assembly of electronic components which is correctly called a decoder 😁

[NIK]

3 hours ago, andyman7 said:

The X suffix models (including R2648X) are non-sound DCC Decoder fitted and use the R8249 installed in the 8 pin socket, factory fitted. Auction houses are not always expert and they clearly did not understand this when doing the description, as with all conventional auctions it is 'caveat emptor/buyer beware'. In this case it works in your favour, even if you want to change the decoder.

 

Hi,

 

Except for those models that don't have 8 pin sockets but come prefitted with a DCC decoder - Pendolino?.

 

A trader bought a second hand loco assuming it had a DCC decoder in it but it just had a blanking plate. Didn't make the profit he'd planned when he had to sell it as DCC ready.

 

Regards

 

Nick

[andyman7]

1 hour ago, NIK said:

Hi,

 

Except for those models that don't have 8 pin sockets but come prefitted with a DCC decoder - Pendolino?.

 

A trader bought a second hand loco assuming it had a DCC decoder in it but it just had a blanking plate. Didn't make the profit he'd planned when he had to sell it as DCC ready.

 

Regards

 

Nick

The Pendolino was unique in that arrangement; also the 'XS' suffix sound fitted locos are different (I believe they actually have 21-pin sockets, this is long before Hornby moved to 21-pin as standard). But all the other X suffix ones just have a standard decoder fitted - of course if the model is bought secondhand it is important to check it hasn't been taken out! 

[NIK]

14 minutes ago, andyman7 said:

The Pendolino was unique in that arrangement; also the 'XS' suffix sound fitted locos are different (I believe they actually have 21-pin sockets, this is long before Hornby moved to 21-pin as standard). But all the other X suffix ones just have a standard decoder fitted - of course if the model is bought secondhand it is important to check it hasn't been taken out! 

Hi,

 

Re checking things out the prospective buyer saw the loco at a show and asked for it to be tested on a DCC layout of the right gauge at the show and it just sat there and buzzed.

 

I wonder if a small, cheap battery powered DCC loco tester could be done as a DIY project?.

 

Whenever I've bought second hand Bachmann EMUs that have DCC decoders in them they have turned out to have early Bachmann decoders in them that were a bit limited (no advanced consisting if I recall) which means I may have to swap them for new decoders.

 

I was told this weekend that a quick DCC conversion for old Bachmann Class 166 3 car DMUs with the motor in the middle car and DC bidirectional lights in the end cars is to use a cheap TCS motor driver decoder in the end cars. The light modules require bidirectional drive which can be provided by the motor drive from a decoder. I was told a CV has to be set (Vmin?) so that the decoder always produces max volts regardless of the speed step sent to the decoder.

I think the TCS decoders have a motor control from Function key facility so the lights can be turned on an off.

 

Regards

 

Nick

[Damo666]

7 hours ago, WIMorrison said:

What value do you get in CV8 when you read it? That will identify the make of the decoder, if not the actual decoder.

Thanks Iain,

 

Didn't want to put it on the DCC track until I knew it was OK, hence the second part to my questions about putting a loco with no decoder on DCC track.

[Damo666]

6 hours ago, andyman7 said:

The X suffix models (including R2648X) are non-sound DCC Decoder fitted and use the R8249 installed in the 8 pin socket, factory fitted. Auction houses are not always expert and they clearly did not understand this when doing the description, as with all conventional auctions it is 'caveat emptor/buyer beware'. In this case it works in your favour, even if you want to change the decoder.

 

Indeed.

And a second purchase from the same auction house was a basic Bachmann Class 66 with a poor attempt at renumbering it. Poor condition which is why it didn't sell for much. When I tested it, it has a sound chip with speaker, so well happy.

[Damo666]

7 hours ago, melmerby said:

That's a Hornby R8249 decoder. The bog standard one.

 

Wonder if I were to swap it over to a 'Rails' 8 pin decoder would I get any extra benefit, like smoother running at slower speeds?

[WIMorrison]

If you swap it for a Zimo decoder you will, not so sure about the rebadged offerings.

[RAF96]

Pendo factory fitted decoder was a unique 7-pin decoder variant ov the R8249. Pendo DCC-Ready was the standard 8-pin socket.

XS suffix models were Hornby sound files loaded to 21-pin ESU decoders v30, 3.5 and 4.0. These files are still available for download on ESU site.

Rails decoder maybe be either a LiaisDCC or DCC Concepts rebadge from memory.

Edited March 17, 2023 by RAF96

[Damo666]

Well, everything seemed to be fine on my NCE system until I tried to change the decoder address from 3 to 5609.

 

Tried to Programme on Track, selected 1 STD and the loco raced for ½ second, then I get the message that it cannot read the CV. I hit enter again for Manu info, the loco races one way and then back for a very short period, and the display says cannot read CV. No response to throttle input.

 

Tried to Programme on Main, selected 1 STD and entered in new long address, but loco wouldn’t respond. Then selected loco address 3 and this too wouldn’t respond.

 

Reset the decoder (Programme on Track – 7 Recovery Programme), loco motor moved in steps as it counted dup the CV numbers, and reset back to address 3. Throttle input of 1 and the loco races for a few seconds and stops. Won’t do anything.

 

Any ideas as to what would cause this strange behaviour? Faulty decoder? If so, why as it was working perfectly earlier and the only thing I tried to do was change the address.

 

As usual, appreciate any help.

[RAF96]

Early R8215 decoders as factory fitted to many locos did not support long addressing and some did not support read back.  You can recognise them by either a white or red spot on the MCU.

They were replaced by the better R8249 basic decoder. These have a blue spot or no spot.

Edited March 19, 2023 by RAF96

[melmerby]

13 hours ago, RAF96 said:

Early R8215 decoders as factory fitted to many locos did not support long addressing and some did not support read back.  You can recognise them by either a white or red spot on the MCU.

They were replaced by the better R8249 basic decoder. These have a blue spot or no spot.

I'd forgotten about the truly awful R8215, as far as I can tell they are probably the same decoders with different firmware in the MCU.

A brand new loco I bought wouldn't even run on the dealer's basic Bachmann EZ DCC setup..

 

If you bought a new loco with an R8215 fitted and complained to Hornby you couldn't operate it on your DCC system, they would send you a R8249 FOC (which I did)

 

 

[Damo666]

On 19/03/2023 at 22:09, RAF96 said:

Early R8215 decoders as factory fitted to many locos did not support long addressing and some did not support read back.  You can recognise them by either a white or red spot on the MCU.

They were replaced by the better R8249 basic decoder. These have a blue spot or no spot.

The decoder has a white spot (my picture on the OP). This explains clearly why I wasn't able to enter a 4 digit long address.

Thanks (I'm still learning....)

[Damo666]

On 20/03/2023 at 12:09, melmerby said:

I'd forgotten about the truly awful R8215, as far as I can tell they are probably the same decoders with different firmware in the MCU.

A brand new loco I bought wouldn't even run on the dealer's basic Bachmann EZ DCC setup..

 

If you bought a new loco with an R8215 fitted and complained to Hornby you couldn't operate it on your DCC system, they would send you a R8249 FOC (which I did)

 

I'll contact Hornby and see what they say. Thank you for the suggestion.