Hornby R1075 Class 08 shunter

[gazzavc]

I recently acquired one of these from a 2nd hand model shop here in Los Angeles.

Trying to program it with my MRC Prodigy Express DCC unit has been an exercise in frustration as it doesn’t seem to recognize the chip.

The loco runs fine using DC power but I’d like to get it running on DCC if possible. I did verify that the chip is present in the loco.

Any help would be appreciated 🙏🏻🙏🏻

[RDS]

Hi

Please post a picture of the chip installation.

[Bulleidboy]

Hi

As this is DCC Fitted, I would assume it would have been fitted with either the R8215 or the R8249 decoder which was the replacement for the R8215. The R8215 was the first decoder Hornby introduced, and until very recently was the decoder I had fitted into my Class 08 - it ran well. I am not sure if the R8215 was NMRA compliant - the R8249 was.

[Going Spare]

Coming from set R1075, this loco should have the factory-fitted 4-pin decoder which I believe carried part number X9659 and may be the same as what is now offered as R7274.

[Fishmanoz]

I agree with Going Spare in all respects. I have the set, my first purchase this century.

[ColinB]

I think I had this issue with one of the early Hornby decoders, someone on this site identified that there were issues with these early decoders. I think in the end I binned it, converted it to six pin and used a Zimo decoder.

[gazzavc]

Hi

Please post a picture of the chip installation.

 

 

 

 

[RDS]

That's a very good picture. Can anyone confirm the chip and offer any advice.

[Going Spare]

Yes, as expected it is the Hornby factory-fit 4-pin X9659/possibly R7274.

[96RAF]

Compare

[Going Spare]

So, although the images are of one top and one bottom surface of the two decoders judging by the cable connections, it looks as if X9659 and R7274 are not physically the same (do they act differently?) and the OP's decoder giving him compatibility problems is the X9659. Over to those with the DCC know-how.

[Bulleidboy]

Sorry, I was not aware that some factory fitted loco's came with four pin decoders.

[Brew Man]

Yes, back in th' olden days.

[96RAF]

So, although the images are of one top and one bottom surface of the two decoders judging by the cable connections, it looks as if X9659 and R7274 are not physically the same (do they act differently?) and the OP's decoder giving him compatibility problems is the X9659. Over to those with the DCC know-how.

 

 

The X number was simply the spare part designation on the service sheet. The R number being the retail packaging SKU. No difference twixt the two operationally. The only physical difference may be the colour of some components as production rolled along.

[Fishmanoz]

That picture is not original if my memory serves me correctly. The decoder should be direct plug not harness.

No matter though, they are all 8249 variants.

[ColinB]

Either way whether it is "Plug in" or on a harness it should program that is something to do with the electronics. I must admit I rewired anything with 4 pin because it is Hornby unique, but looking at the photo the outer wires are supply, the inner wires motor. So basically you can plug it in upside down and it should still work it will just drive backwards. As I said in my first post it is a replacement fix. Personally I would rewire it as a six pin if your skills are up to that, then your choice of replacements improves dramatically. The easiest way I have found to do it is buy a Pecket DCC socket which is 6 pin and the PCB is a decent improvement to the loco.

[Howbi]

gazzavc.....have you tried resetting the decoder by writing value 8 to CV8. This will reset to default with an address of 03.