Neff Warming drawer failures

[Nick0207]

Neff sell a warming drawer to match their hide and slide oven range. They are surprisingly useful and work well (for a time). The model is Neff N17HH11NOB (140mm high) and the larger N17HH20NOB (290mm high).
Mine failed after 3 years and was going to cost probably around £150+ to repair by Neff (£99 labour/call out plus parts on top). There seem to be many owners who suffer from a similar failure, Neff's own website does not make good reading , have a look N17HH11N0B

The problem with mine was that the red light kept flashing when the drawer was closed and only a small area of the hot plate (rear right hand side) got at all warm (by the fan heater which is in the side of the unit). The fault turned out to be with the power connector at the rear of the pull out drawer which was failing. It's basically a kettle connector for cordless kettles. The control module will not connect power to the drawer unless it detects it's closed. When the connector begins to fail the hot plate will not get warm as the power controller thinks the drawer is open.

Replacements are available from here 00612218 or ebay Bosch Neff Siemens Coupling 612218 | eBay

Relatively easy to fit but do not attempt unless you are competent. The whole device has to be removed as both parts of the power connector need replacing. The drawer itself is easy to remove, just remove the two screws from inside the drawer (one each side) and the drawer can be lifted out.
On the main unit the connector is fitted inside the panel on the rear (two screws).

 

[Rob GU10]

This is very helpful Nick.

I have the same problem with a three year old Neff N21H40N3GB. I slid it out from under a C67M70N3GB oven/microwave and discovered the oven/microwave was left hanging by its front two screws. The front top panel bent as a consequence - but I bent it back more or less. It rattles a bit now! So its worth pointing out to anyone with this set up that the warming drawer is built to have the oven/microwave sit on top - no kitchen panel supports it. My ignorance. Remove the item above before sliding out the warming drawer.

I haven't bought the spares yet. I removed the metal panel at the back of the warming drawer, revealing the white plastic sensor. I didn't go further at this stage but am not sure the best way to access the 'kettle connectors'. Most of the box is riveted rather than screwed. Do you have any advice here? I suppose a service manual is unavailable anywhere.

I'm not prepared to request a NEFF engineer yet - it will cost half the price of the drawer and if they fail every three years or so this could be costly. I had the oven/microwave inverter replaced when it was just over two years old at a cost of £150. The engineer switched it on after replacement and discovered the fuse had blown. At that point I wondered whether the fuse had been the only problem in the first place - who knows?

Overall, I'm disappointed with the reliability of these items. I have also read your microwave thread - keep up the good work.

 

[Nick0207]

On the combi fuse, it has to be a 16 amp supply. If it has been installed with a 13A socket the fuse will fail eventually. This means (usually) a separate spur from the main fuseboard. If the inverter had failed it might have blown the main fuse as well though?

It isn't necessary to remove any rivets to replace the connectors on the warming drawer on the model I've got. The only tricky part is removing the plastic ring that holds one of the parts in (have a look at the ebay link for a picture of both halves). It is possible to remove the ring by rotating it after prising up the retaining clips but you get a new one in any event. The other half of the connector is held in by two screws. The model you have is different from mine although looking the pictures of it on the Neff site it looks the same fundamentally. Just photograph everything before you start dismantling. The actual drawer itself can be lifted off the telescopic sliders once the two screws inside (visible once the drawer is opened) have been removed. The plastic panel on the back of the drawer has two screws to allow removal to access one half of the connector. On the main unit there is a stainless steel box on the back which needs to be unscrewed to remove it to access the fixed part of the connector.

And yes! depending on the way the drawer is installed in the kitchen unit, it is essential to remove the combi above it first if it sits on top of the drawer.

 

[HitchcockSmith]

Hi @Nick0207 and @Rob GU10 , I had the same flashing red light, ordered the electrical coupling from Bosch and replaced it, thanks to the clear guidance above ... same flashing red light exists and now wondering if it's the power control module. Before spending another £100 on one of those I thought I'd give Neff a chance to respond considering all the Neff Warming Drawer failures reported on multiple review sites. Their only offer was an Engineer at £99 plus 30% discount on parts. I'm assuming the Engineer may need to visit more than once so concerned i'd end up spending close to £300 when I could buy a more reliable brand despite having what will look like Dr. Frankenstein's oven.
Very dissapointed with Neff's response considering the high volume of reports of this defect on their own site as well as the same on multiple retailer's review sites. Anyway, any other ideas what the error may be beyond power control unit. I believe it's this part Neff Power Module that I need for the pcu, according to Neff.
Thanks again for the guidance with the first attempt.

 

[Rob GU10]

Sorry to hear this. The ownership of these recurrent design problems by the supposed 'quality' brands is hard-nosed and in no way supports their supposed company values. I'm fed up of fighting consumer battles and gave up.

I can't help. I had the same concerns - that I would replace the coupling and fail to fix the problem. I had already bent the combi panel above, was frustrated, and decided to leave it alone and not use the warming drawer. This weekend we tried the drawer to warm some plates and it worked. The light flashed for a whileand then stayed on. Clearly an intermittent fault - maybe a generous push to the door helped.

We shall the ovens to warm plates if it fails again. The warming drawer will be a cosmetic fixture. Poor show really.

Keep us informed though!

 

[Nick0207]

I'd doubt it's the power module, the alignment of the connectors is important. If you can (and only if you're comfortable handling mains electricity) try bypassing the connector by connecting the drawer directly to the feed wires. This will show if the power module is working or not. The drawer has a 240v supply when activated. If it does work then for some reason the power connector is not aligning correctly.

I recall I did get a flashing light after repair initially but I think the electronics needs resetting by power cycling (leave it unplugged for 60 seconds) and then try again. Push the drawer firmly into the housing after switching it onto position 4. After a few seconds it should stay on.

 

[Nick0207]

Well ironically, my warming drawer (N17HH11N0B) has just failed again with a flashing red light!! I thought it might be the connector again although it isn't long since i fitted a new one but this time it turned out to be the heating element in the pull out drawer (the connector feeds power to this when the drawer is pushed in). Easy to check with an ohm meter (should read about 120 ohms) or just (safely!) directly connect the drawer wires (once the connector has been removed to the 240v mains to see if it heats up. Mine doesn't.....
Replacements are about £180 incl vat (part number Neff 00772151 if the drawer has a handle or 00772150 if it doesn't) and is an easy item to replace as the drawer can be removed without taking the whole thing out of it's kitchen unit. Might be worth looking out for a second hand unit for spares though as they appear quite frequently on eBay.

 

[DevonChris66]

I also have the Neff N21H40N3GB and like Rob it has failed AND we've had the inverter in the combi replaced. Thanks for the tip on supporting the combi but here is my question. I have sourced an ex-demo replacement and wish to swap out the sliding draw only. The draw sits in a surround which I can see might support the combi, but removing the two screws from the draw and taking the draw off the slider surely would leave the supporting draw structure in place?

 

[Nick0207]

Yes, you can just remove the drawer by taking out the two screws that secure it to the runners and lifting it up and out without any problem for the unit above. it's only if you take the whole chassis out that whatever unit is above it would need removing unless it is on it's own shelf.
Yours is not the same model as mine so there may be some differences with my description though.
It's fairly easy to test the heating element continuity once removed to see if there is a failure of the element. There should be a plastic plate on the back of the drawer, remove the two screws and push the plate down to release it if you need to get to the connector.
I've just replaced my drawer and it's now working again (until the next thing fails)!

 

[DevonChris66]

Thanks, I'm hoping to swap the new drawer for the old and solve the issue.

 

[MrFixIt123]

I also own a Neff Warming Draw (N17HH11N0B/02). The unit was purchased late 2016 but did not get used until early 2017 due to a delayed kitchen installation. Even then it has been infrequently used which makes its failure so early very disappointing for the £352 outlay. It failed early 2019, and because is now out of warrantee and I have some electrical/mechanical skills decided to investigate the cause of failure myself rather than pay the engineer callout costs.

The failure symptoms are when turned on by the rotary switch the unit gives the flashing red light even with the draw closed, but strangely sometimes when switched on the red light does not flash immediately even with the draw closed, but eventually does flash. In all cases the Hot Plate does not get hot, but on switch setting 4 the fan heater (left hand side behind the switch) does work, then after a while red light starts flashing.

I removed and dismantled the unit, first inspecting the spring-loaded Coupling (NEFF Part No 00612218, £31.34) at back of the Hot Plate draw. All was fine, no burning or signs of mechanical / alignment damage so this is not why the Hot Plate is not working.

I disconnected the Hot Plate terminals, and checked its resistance with a multimeter. I got a reading of 125 Ohms so decided to connect 240vAC directly, bypassing the units Power Module, to see if it get hot. Yes, it did, so it’s not a failed Hot Plate or the spring-loaded Coupling causing the problem.

I then checked the voltage being supplied by the Power Module (NEFF Part No 12025294, £102.26) to the Hot Plate and found it was 5vDC, it should be 240vAC. I traced the cables back to the Power Module which had two Omron Relays (Omron Part Nos G5LA-1, 10A / 277vAC) pin mounted on the Printed Circuit Board (PCB). One is being used to switch the Hot Plate the second the Heater/Fan.

5vDC is probably PCB’s/relays control voltage, therefore it seemed to me the Hot Plate relay has failed causing the fault. This theory was backed up by the second relay working and supplying the Fan Heater with 240vAC on rotary switch setting 4.

An equivalent replacement relay is £2.72 from RS Components (Part No 793-3768), but to remove the old relay would probably damage the delicate Power Module as the relay is pin mounted to the PCB and is surrounded by delicate surface mounted components, but I had a go anyway. Yes, you guessed it, removing the relay did damage some of the PCB’s power tracks because the relay pins were tightly fitted and soldered to the PCB. Also, heat has probably damaged some surface mounted components as well due to discoloration. So, I admitted defeat ordering and fitting new NEFF Power Module which has fixed the fault. I can hear the relays clicking on/off and the Hot Plate gets hot, until the next time it fails.

£102.26 is expensive for a simple circuit board but much cheaper than a service engineer callout plus parts, or buying a new unit. Can’t say I’m impressed with how long the Warming Draw has lasted considering its limited use, and the NEFF website reviews tell the same story, I’ll be adding comments myself. Hope my experience has been useful.

 

[philip44]

Many thanks to MrFixIt123 for the useful and in-depth guidance. I also own a warming drawer, but mine is a Bosch (same model as the Neff, that came out of a different door in the same factory with a different badge!) Mine was vintage 2015, but used quite regularly, and had the same fault.
Like MrFixIt123, I traced the fault to the circuit board, as the drawer had good continuity, and connection to the "kettle" plug/socket.
The relays are 12vdc and not 5vdc. They are marked on the top, and coil resistance was similar to what RS had on the website for a 12vdc coil relay. The 5vdc coil had a very low resistance in the comparison on the website. Well done to RS.
I think (without the knowledge of someone from Bosch/Neff) that the 5vdc that was seen at the "kettle" socket may possibly be a "monitor/sensor" voltage to show when the tray is open/closed - hence possibly the delay in operation, and the circuit board operation voltage??
I changed both relays for RS 793-3777 ("Finder 36 Series" SPDT Non-Latching Relay PCB Mount, 12V dc Coil, 10A) 12vdc relays (Omron relay G5LA-1 is not available (obsolete) but there is a G5LA-14, although the dimensions are different). Removal of the relays was done using a Portasol gas soldering iron on it's hottest setting, and a solder sucker. I used the gas soldering iron instead of an electrical one, so that there was no earthing problems. The reason for the hottest setting of the soldering iron was so that the solder melted quickly before transferring any heat to adjacent components. After all the solder was removed (as much as possible), I used a small screwdriver to gradually lift the relay while heating one leg at a time.
I don't know if the circuit board has connections both sides of the relay, and maybe sandwiched in-between, but I allowed a few seconds longer for the solder to run, in case there were connections both sides of the board and maybe in-between.
Success - the drawer now heats up on heat 1 to 3 and the fan comes on at 4.
Now to get the oven out again, and put the drawer in, with the oven going on top of it!!

 

[Boiler10]

Big thanks to MrFixIt123 and Philip44 for pointing me in the right direction to get an economical fix. I have a Siemens warming drawer Model BI630CNS1B/02 with the same symptoms, flashing blue light and warming plate only getting slightly warm in the back right corner on setting 4.

Reading this thread I jumped in a bit too quick and ordered the “kettle” connector assembly before taking it apart as it seemed like a plausible issue. Both ends of the assembly are easy to replace but I measured the resistance through the old and new connector and there wasn’t much difference so no surprise when it didn’t fix the problem. I also tested the resistance of the hot plate which was about 120 Ohms so I knew that was OK.

Reading MrFixIt123 and Philip44 post got me looking at the Power control module behind the control knob. I found that the second relay had an in circuit resistance of about 4 Ohms across it’s Normally Closed contacts! The RS Spec sheet says it should be less than 0.1 Ohms so something not correct here. The NC contacts also appear to be in use as they go to the PCB connectors.

The fitted Omron relay is obsolete and the nearest Omron equivalents (and some others) are physically too large at 22mm not 19mm so be careful what you select. The coil voltage for the relays on mine was 12VDC (NOT 5V) and I liked the look of an HF device HF3FF/012-1ZST. I found these on eBay 4 for £3.03. I only replaced the defective relay (if it isn’t broken don’t fix it) and used solder wick to remove all the solder so I could see the pins in the hole. It then just took a little jiggling to pull the relay out. (I’d say if you don’t do much soldering give this bit to a friend who does. I managed to get the relay out without any damage to the tracks or surrounding area).

New relay in and back together it all works. Hot plate on 1-3 and Fan and heat on 4. As mentioned, I also suspect the NC contacts are used to detect if the drawer is closed and the high resistance relay fault fools the control unit into thinking the drawer is open. Hope this helps someone else.

 

[Steve Dando Knight]

I had the same problem with flashing red light and the drawer element not getting hot. I arranged a £99 service call. The Power Module (material number: 12025294) needed replacing - They did however discount the part by 50% as the unit was onlly three years old. Total cost was £150.13 including VAT.

Very disappointed that a really very simple "Quality" product should fail so quickly.

 

[philip44]

If anyone else has this problem and can change the relays themselves, then an upgrade is possible with this 15A current contacts relay from Radio Spares - and maybe other outlets.

This is RS Stock 134-8400, a Relpol SPDT Non-Latching Relay PCB Mount, 12Vdc Coil, 15A current contacts - £3.05.

Dimensions are the same as for the 10A Finder 36's I fitted. Omron's are too long to fit in-line.

 

[Niksles]

Probably not the most technical repair.
Had the same issue with the Neff Warming Drawer N17HH20N0B/02, all readings as MrFixit123 had with my meter; i.e. only 5v DC at the drawer connector.
Opened all relevant panels and removed the Control Module completely, gave the relays a couple of sharp wacks with my screwdriver handle and wired it all up again to find it now works (240v AC at the drawer connector) with hot plate heating and fan running on position 4.
Worth a try before ordering a pricey part, although I expect this will not be a permanent solution!
Oh, many thanks to all above for the advice/information.

 

[Robertofrog]

Ok, so I'm also trying to fix my Neff N17HH20N0B/02 drawer with the flashling light.

Like others here, on setting 4 the back right side of the plate was warming marginally, which I'm assuming is the fan. There was no warming on settings 1 to 3.

Taking out the draw, and testing the resistance across the two outer elements of the connector I got approx. 120 ohms, which is correct, so I'm deducing that a faulty drawer was not my issue (I managed to figure out that the central pin on the coupling is earth).

Then switching the drawer on, instead of 240v across the outer pins of the rear coupling I was getting 5vdc. (I'm now assuming this is a signal voltage, and 240v ac is applied only when the drawer is closed and the coupling is made, but having read all of the above posts that wasn't clear, and I concluded that I needed to replace the control module). I'm not confident to be messing about with soldering etc, and it's a relatively simple replacement - just a couple of screws and 2 connectors.

The PCB photos one the website matched mine exactly but when the replacement part arrived it seems to have a very slightly different chipset components/configuration than the original. The paperwork with it though had photos of the old chipset configuration (matching my original) and on checking the supplier assured me it will work for this model.

So I'm guessing that it is a slightly newer PCB design. Interestingly it has instructions for calibration of the drawer based on ambient temperature. (I couldn't get to flip into service mode though).

Anyway, long story short it still doesn't work - still the flashing light, and not even a fan now. I'm guessing this is due to the new pcb design - no draw closure, no play.

So now I'm turning my focus on kettle coupling assembly after all. I can't see what else it could be. I tried bending a pin on it out slightly to see if I could generate a contact, but have ended up mashing that pin. So next step is a £30 replacement. I don't fancy mains wiring the drawer itself, and the coupling looks simple to replace so I'll try that next. It's not unaffordable.

Kind of wishing I'd tried that in the first place now, before paying for the replacement power/control module.

The thing I think I've learnt, to add to all of the earlier posts, is that even if the problem is simply the kettle connector/coupling, then you may only get 5vdc across the rear connector terminals until the drawer is closed and the coupling circuit is made successfully. Rushing to replace the control module may be costly and unnecessary. I'll update when I know more.

 

[Boiler10]

Ok, so I'm also trying to fix my Neff N17HH20N0B/02 drawer with the flashling light.

Like others here, on setting 4 the back right side of the plate was warming marginally, which I'm assuming is the fan. There was no warming on settings 1 to 3.

Taking out the draw, and testing the resistance across the two outer elements of the connector I got approx. 120 ohms, which is correct, so I'm deducing that a faulty drawer was not my issue (I managed to figure out that the central pin on the coupling is earth).

Then switching the drawer on, instead of 240v across the outer pins of the rear coupling I was getting 5vdc. (I'm now assuming this is a signal voltage, and 240v ac is applied only when the drawer is closed and the coupling is made, but having read all of the above posts that wasn't clear, and I concluded that I needed to replace the control module). I'm not confident to be messing about with soldering etc, and it's a relatively simple replacement - just a couple of screws and 2 connectors.

The PCB photos one the website matched mine exactly but when the replacement part arrived it seems to have a very slightly different chipset components/configuration than the original. The paperwork with it though had photos of the old chipset configuration (matching my original) and on checking the supplier assured me it will work for this model.

So I'm guessing that it is a slightly newer PCB design. Interestingly it has instructions for calibration of the drawer based on ambient temperature. (I couldn't get to flip into service mode though).

Anyway, long story short it still doesn't work - still the flashing light, and not even a fan now. I'm guessing this is due to the new pcb design - no draw closure, no play.

So now I'm turning my focus on kettle coupling assembly after all. I can't see what else it could be. I tried bending a pin on it out slightly to see if I could generate a contact, but have ended up mashing that pin. So next step is a £30 replacement. I don't fancy mains wiring the drawer itself, and the coupling looks simple to replace so I'll try that next. It's not unaffordable.

Kind of wishing I'd tried that in the first place now, before paying for the replacement power/control module.

The thing I think I've learnt, to add to all of the earlier posts, is that even if the problem is simply the kettle connector/coupling, then you may only get 5vdc across the rear connector terminals until the drawer is closed and the coupling circuit is made successfully. Rushing to replace the control module may be costly and unnecessary. I'll update when I know more.

Hi Robertofrog, you may not wish to try desoldering/soldering but you could measure the resistance across the relay pins. You can compare the two identical relays. If you have my issue with the faulty relay you will see a difference across the NC normally closed pins of the two relays. It sould be an almost dead short. You can measure this in circuit, with the board removed of course. Might narrow the issue down. Good luck

 

[Robertofrog]

Hi Robertofrog, you may not wish to try desoldering/soldering but you could measure the resistance across the relay pins. You can compare the two identical relays. If you have my issue with the faulty relay you will see a difference across the NC normally closed pins of the two relays. It sould be an almost dead short. You can measure this in circuit, with the board removed of course. Might narrow the issue down. Good luck

Wow, great. Many thanks for this. That's a good idea. I have the brand new pcb now, so I need to try the kettle connector next (also because I damaged it). Failing that, I'll go back to the old pcb and have a go. This will definitely be good advice for others here looking to diagnose.

 

[Nick0207]

Really useful info on the relay problems with the control unit, thanks guys. As I have already replaced in the past on my unit, the drawer (kettle) coupler and, after a second problem, the actual drawer unit, I suspect it's only a matter of time before the power control module fails!
The drawer element/hot plate on mine had failed prob because it had not been stuck to the drawer glass properly. It's similar to a flexible stick on heated car window demister and on mine it had peeled up at several places and where it was creased the element had failed. No alternative but to get a replacement drawer unit although I was lucky enough to find an unused spare on ebay for £80

From my experience with these warming drawers, the best test sequence if you get the dreaded flashing red light is first to measure the resistance of the drawer hotplate after removing it from the unit (very easy to do as only two screws and can be removed without taking out the whole unit). If this reads about 125 ohms then the drawer and heater element is ok and hence the fault is upstream. For a further test of the drawer, connect the drawer wires directly to a 240v supply via a 3 amp fuse and it should heat up.

If not then:

Secondly, after removing the whole unit ( if you have an oven located above, the oven MUST be removed first as it sits on the warming drawer! Do not allow the oven to hang on it's mounting screws without the warming drawer in place..) Bypass the kettle connector completely by connecting the wiring connections directly to the drawer wires. Note- only do this is you are competent handling 240v live mains connections. This will test the kettle connector and the control sense circuit that detects the drawer is closed. If the drawer base heats up on position 4 then the connector is the problem and will need replacing. If the hot place doesn't heat up then it is likely to be the control module relay.

 

[Steve Dando Knight]

Ok, so I'm also trying to fix my Neff N17HH20N0B/02 drawer with the flashling light.

Like others here, on setting 4 the back right side of the plate was warming marginally, which I'm assuming is the fan. There was no warming on settings 1 to 3.

Taking out the draw, and testing the resistance across the two outer elements of the connector I got approx. 120 ohms, which is correct, so I'm deducing that a faulty drawer was not my issue (I managed to figure out that the central pin on the coupling is earth).

Then switching the drawer on, instead of 240v across the outer pins of the rear coupling I was getting 5vdc. (I'm now assuming this is a signal voltage, and 240v ac is applied only when the drawer is closed and the coupling is made, but having read all of the above posts that wasn't clear, and I concluded that I needed to replace the control module). I'm not confident to be messing about with soldering etc, and it's a relatively simple replacement - just a couple of screws and 2 connectors.

The PCB photos one the website matched mine exactly but when the replacement part arrived it seems to have a very slightly different chipset components/configuration than the original. The paperwork with it though had photos of the old chipset configuration (matching my original) and on checking the supplier assured me it will work for this model.

So I'm guessing that it is a slightly newer PCB design. Interestingly it has instructions for calibration of the drawer based on ambient temperature. (I couldn't get to flip into service mode though).

Anyway, long story short it still doesn't work - still the flashing light, and not even a fan now. I'm guessing this is due to the new pcb design - no draw closure, no play.

So now I'm turning my focus on kettle coupling assembly after all. I can't see what else it could be. I tried bending a pin on it out slightly to see if I could generate a contact, but have ended up mashing that pin. So next step is a £30 replacement. I don't fancy mains wiring the drawer itself, and the coupling looks simple to replace so I'll try that next. It's not unaffordable.

Kind of wishing I'd tried that in the first place now, before paying for the replacement power/control module.

The thing I think I've learnt, to add to all of the earlier posts, is that even if the problem is simply the kettle connector/coupling, then you may only get 5vdc across the rear connector terminals until the drawer is closed and the coupling circuit is made successfully. Rushing to replace the control module may be costly and unnecessary. I'll update when I know more.

The bottom line is that the drawer should never have failed in the first place - NOT what we expect when buying a so called "quality" product. I paid for A NEF engineer to come out and fix ours - not sure I will be buying NEF again!

 

[vlad158]

Not any assistance but just recording another failure, really don't think these are anything like the quality they should be for £400+ - ours failed after 5 years so we were lucky, but on getting an engineer out have discovered it never worked properly - apparently setting 4 should have started an internal fan - hot air blower (it has never worked), always thought it was a bit feeble heating just via the element at the bottom of the drawer.

 

[Robertofrog]

Ok, so I'm also trying to fix my Neff N17HH20N0B/02 drawer with the flashling light.

Like others here, on setting 4 the back right side of the plate was warming marginally, which I'm assuming is the fan. There was no warming on settings 1 to 3.

Taking out the draw, and testing the resistance across the two outer elements of the connector I got approx. 120 ohms, which is correct, so I'm deducing that a faulty drawer was not my issue (I managed to figure out that the central pin on the coupling is earth).

Then switching the drawer on, instead of 240v across the outer pins of the rear coupling I was getting 5vdc. (I'm now assuming this is a signal voltage, and 240v ac is applied only when the drawer is closed and the coupling is made, but having read all of the above posts that wasn't clear, and I concluded that I needed to replace the control module). I'm not confident to be messing about with soldering etc, and it's a relatively simple replacement - just a couple of screws and 2 connectors.

The PCB photos one the website matched mine exactly but when the replacement part arrived it seems to have a very slightly different chipset components/configuration than the original. The paperwork with it though had photos of the old chipset configuration (matching my original) and on checking the supplier assured me it will work for this model.

So I'm guessing that it is a slightly newer PCB design. Interestingly it has instructions for calibration of the drawer based on ambient temperature. (I couldn't get to flip into service mode though).

Anyway, long story short it still doesn't work - still the flashing light, and not even a fan now. I'm guessing this is due to the new pcb design - no draw closure, no play.

So now I'm turning my focus on kettle coupling assembly after all. I can't see what else it could be. I tried bending a pin on it out slightly to see if I could generate a contact, but have ended up mashing that pin. So next step is a £30 replacement. I don't fancy mains wiring the drawer itself, and the coupling looks simple to replace so I'll try that next. It's not unaffordable.

Kind of wishing I'd tried that in the first place now, before paying for the replacement power/control module.

The thing I think I've learnt, to add to all of the earlier posts, is that even if the problem is simply the kettle connector/coupling, then you may only get 5vdc across the rear connector terminals until the drawer is closed and the coupling circuit is made successfully. Rushing to replace the control module may be costly and unnecessary. I'll update when I know more.

UPDATE:
Ok, so I have now replaced the kettle connector, as well as the power/control module and guess what - still the red flashing light. Aargh!

I have 118 ohms on the drawer unit, so I didn't think it was that, but now I'm out of other ideas. Apart from the drawer, the only thing I haven't replaced is the fan. I have noticed that it is silent though, on setting 4, so I'm wondering if that has failed.

Alternatively, whether I need to go through the initialisation/calibration service mode sequence that the new power control design seems to have. It's a really complicated sequence though, and you only get one second to complete each step otherwise it stops.

Really, really fed up. May have to admit failure and get a Neff guy in. %(

 

[Boiler10]

If IRC the fan doesn't work (on setting 4) when in failure mode I.e. the light is flashing. So I don't think the fan will be faulty. Are you sure they sent you the correct power control module no one else has mentioned the calibration routine.

 

[Stereomike9000]

Probably not the most technical repair.
Had the same issue with the Neff Warming Drawer N17HH20N0B/02, all readings as MrFixit123 had with my meter; i.e. only 5v DC at the drawer connector.
Opened all relevant panels and removed the Control Module completely, gave the relays a couple of sharp wacks with my screwdriver handle and wired it all up again to find it now works (240v AC at the drawer connector) with hot plate heating and fan running on position 4.
Worth a try before ordering a pricey part, although I expect this will not be a permanent solution!
Oh, many thanks to all above for the advice/information.

I had exactly the same issue with the flashing light on the Neff N17HH20N0B/02.
I'd replaced the power connector on the draw with no luck (the warming draw stayed cold but the side heater came on intermittently).
I tested resistance of the draw and got 120 ohms so was happy that the draw itself was not the issue.
Finally I took Niksles advice and decided to remove the pcb and give the relays a tap.
Thank you Niksles, my warming draw is now working perfectly!