Most Un-repairable device ever! Honda Eu20i inverter module

[sparksflying]

Hello,

I am trying to repair a Honda Eu20i Inverter Generator. The engine runs fine and the alternator seems fine as well (low resistance between windings and 300v between phases when running)

The board also seems to be working to a degree, the "Economy" function works and slows the engine when there is no load. Unplugging the board makes the generator run out of control and bounce off the rev limiter.

When plugging in the alternator to the board, voltage drops from 300v down to 1.7v. Sometime I can't get the generator started with it plugged in (bogs the engine down and wants to stall). So I'm thinking there is something wrong with the rectifier or a mosfet.

The board is completely potted. I've de-potted boards in the past with heat, but this substance is immune to heat. I've had to use Dichloromethane to slowly remove the potting. It only come off in 1mm layers and the potting is about 10mm thick...

I've uncovered some circuitry, but have come to the realization that all the the power components are under the board and somehow attached to the heatsink alloy case. I think manufacturer has screwed all the mosfets and diodes to the case, placed the board, soldered the legs and then potted the whole thing.

Is there any hope for this?

[Ian.M]

Probably not, as you'll never be able to expose the underside of the board without damaging it, (if you can even get down to the board without destroying smaller passives), and Honda are big enough to get custom modules made, so the power semiconductor dies may actually be bonded direct to the heatsink/case, and if so, they would be unrepairable even if you could magically remove the potting compound.

IMHO you are going to have to bite the bullet even though its a >$400 part.

[voltsandjolts]

Yeh, sorry to say that module is destined for the bin. Do they pot them for protection from the rain or from a repair man? Looking on ebay, those Honda inverter modules (and I mean just the electronic module itself) have been selling by the dozen. Looks like there is an issue with those units. So expensive too. 

[BradC]

This is pretty much the predominant failure mode of any make of inverter generator.

Looking at the Honda patent they use an SCR bridge regulator up front and an IGBT or MOSFET sinewave inverter at the other end. Simple and bloody impossible to get at to repair. I've seen a couple of teardowns somewhere that indicates the power semi block is usually custom and die-bonded.

I've toyed for a few years with the idea of making a generic replacement inverter module just to see if I could make it work. The modules for the Honda and Yamaha are generally >$1k, but the replacement modules for the Chonda units are ~$200.

[voltsandjolts]

The OP needs module 31310-Z07-C66 and the cheapest price I see in the UK is around 700GBP!!
At that price, I would buy a new generator with warranty and swap over the modules!

[Ian.M]

Although I have as little sympathy for big corporations selling unreliable crap as any of us, Honda UK don't stock it any more: https://store.honda.co.uk/generators.list
so you'd be shafting an independent dealer. 
Also, as the part carries a laser etched QR code which may well be serialized, even if its *NOT* partially depotted and visibly corroded like the O.P's, you risk trouble if the dealer tries to get a warranty replacement rather than sending off the whole generator to a service center. At best that would go "Refund denied", but if you'd already been refunded, I wouldn't be at all surprised if the dealer  made a police report so they could circulate your details as 'likely to attempt return fraud'.

[kaz911]

I would look for another EU20i as a donor.

In the UK at least you can find the EU20i's for peanuts if they are "for parts" and that includes running ones where only pull start cable is not working.

I have an EU20i that works perfectly - and it has served me incredibly well and have managed to power up clean enough for my solar panels to start producing. Not many generators can pull that off with clean enough sine wave to enable solar part generation.

My EU20 started up as an Australian model - which I have "converted" to a UK model (front panel replacement) as the 230v Aussie connectors kept falling out.

[Marco]

Put it in the solvent in some tupperware and in an ultrasonic cleaner and let it run for a while outside? It will likely get under there eventually.

PS. oh I guess it would destroy the PCB too.

[CaptDon]

I can say I will never buy a Honda generator again. We had poor luck with an Onan opposed twin 4kw unit in a mobile broadcast studio so we spec'd in Hondas in the new mobile studio. Nothing but problems from day one!!! They used nylon or teflon needles valves to control fuel level in the carburetors. These would flex and take on a bent shape and allow the carbs to flood. On newer units the carb overflow is directed into the crankcase thereby diluting the engine oil. The engine oil got so high that the units went nuts with HEAVY smoke. When opening the oil fill to examine the oil level, fuel diluted oil freely poured out by the quarts!!! The local Honda repair center replaced these needle valves several times (in and out of warranty). We had two units, a 6Kw side mounted unit and a 4Kw under the massive hood. Both suffering exactly the same problems. Honda NEVER came out with a sensible 'brass with rubber tip' replacement which Briggs and Stratton has used for about 40 years!!! The final blow was both of these units uncontrollably burning oil because the bores, pistons and rings were shot from being gas washed by the diluted oil. Honda, expensive to buy and expensive to maintain during their relatively short life cycle. Buy something else!!! Something that can survive dumb mistakes and abuse!!

[Renate]

I ran into that on a Yamaha, same deal, same potted module.
There are a lot of things that throw you off.
First, the line voltage indicator is a cheesy neon that even when glowing is never unambiguous.

The electrolytics are a high stress point.
Presuming that, I Dremeled the capacitors out, found the PCB and stuck in my own cap (only one in this circuit).
Unfortunately, I got flummoxed! We started things up with my DVM on the cap. The voltage went to 1000!
I said, "...." and shut it down.
It turns out that my (cheap) DVM was sensitive to ignition noise and *possibly* it was all working.
In any case, try the caps. It's a case of looking under a streetlight because it's easy.

I took the module down to the metal, more from curiousity.
The MOSFETs and diodes are stuck in the casting.
I found no electrical problem with them.

[voltsandjolts]

<...rant...grumpy face...more rant..>

Honda are being a**holes charging that kind of money for the potted module, especially when they seem to be rather frail. If it were a case of me getting totally screwed by them or me screwing Honda, I'd pick the latter. They could still make a healthy profit at half that price. Also, I don't see how an independent dealer would be left to foot the bill of a Honda warranty repair, as you suggest. I'd be interested if you could explain that please.

[Ian.M]

... because Honda can prove its been tampered with so the dealer may have to eat sh!t and like it unless their Honda rep is willing to go to bat for them.

[m3vuv]

have you tried dunking this in paint stripper,i think its methyle chloride?.

[Renate]

Actually, I used a heat gun and picked out the pieces as they became rubbery.
At that point I was only doing a post-mortem out of curiousity.

[voltsandjolts]

... because Honda can prove its been tampered with so the dealer may have to eat sh!t and like it unless their Honda rep is willing to go to bat for them.

This is nonsense of course.

The dealer will contact the mothership to request authorisation before carrying out any warranty repair work. If the mothership approves the claim they will issue a billing reference which the dealer can use to claim the agreed parts and labour costs. This is to avoid any liability for costs on the dealer. The mothership may indeed conduct diligence checks on part serial numbers prior to approving such a claim. Your suggestion that dealers carry out ad-hoc warranty repair work, at their own expense, then say 'hey mothership, you owe me $x for warranty work this month' is frankly laughable.

Honda is charging around half the cost of a new generator for the inverter module alone, a part which seems to be frail and commonly fails. I view this as customer hostile pricing and the danger of that is creating hostile customers. Unfortunately, we are likely to see more of these high parts costs, as manufacturers respond to having the 'right to repair' legislation forced upon them in more jurisdictions.

[Ian.M]

So you must think that Honda owns the tampered with generator at the time of the claim for warranty repair.   Let me set you straight here.  The independent dealer's inventory is either outright owned by the dealer or is held under a floorplan loan, typically secured on the inventory.  The floorplan may be independent or through a lender tied to Honda.

The dealer is down one new generator, worth whatever the dealer cost is, and is further out the labor to prepare the rejected warranty claim, the dealer cost of the module required to fix it and labor to fit it, and once they have it fixed, cant sell it as new.  At best they can sell it as a discounted 'B' grade 'Manager's Special', loosing the premium a new item commands.  They may do the numbers and decide to write it off as a 'parts mule'.

TLDR:  Return fraud is equivalent to shoplifting and just as harmful to the independent dealer's bottom line.

[voltsandjolts]

If the dealer lets the consumer walk out of the shop with a new/repaired genny without warranty approval from the mothership, then they get to pay for an education. The warranty is backed by the oem not the dealership.

The potting compound used here to block repair efforts is like the old fashioned version of modern DRM. You've decided to bark up this tree, little doggy, but this forum is littered with DRM circumnavigation threads, which also dents the margins of manufactures and their dealers. In effect, theft, as you would say. So, you better go for walkies round the forum and get barking

[amyk]

Something is shorted. I wonder if one of those universal input mains inverters might work as a substitute?

[Ian.M]

@sparksflying: I apologize for 'wrestling the pig' in your topic! 

@all,
So 'voltsandjolts' shows no concern that an independent dealer may be left out of pocket for his (proposed) theft by return fraud if they have offered good customer service by refunding/replacing the generator as soon as Honda confirms that that generator serial number is eligible for warranty.  He then resorts to an ad hominem attack. 

I rest my case. 
<PLONK>

Quoted verbatim for evidence:

The OP needs module 31310-Z07-C66 and the cheapest price I see in the UK is around 700GBP!!
At that price, I would buy a new generator with warranty and swap over the modules!

<My reply #5>

<...rant...grumpy face...more rant..>

Honda are being a**holes charging that kind of money for the potted module, especially when they seem to be rather frail. If it were a case of me getting totally screwed by them or me screwing Honda, I'd pick the latter. They could still make a healthy profit at half that price. Also, I don't see how an independent dealer would be left to foot the bill of a Honda warranty repair, as you suggest. I'd be interested if you could explain that please.

<my reply #11>

... because Honda can prove its been tampered with so the dealer may have to eat sh!t and like it unless their Honda rep is willing to go to bat for them.

This is nonsense of course.

The dealer will contact the mothership to request authorisation before carrying out any warranty repair work. If the mothership approves the claim they will issue a billing reference which the dealer can use to claim the agreed parts and labour costs. This is to avoid any liability for costs on the dealer. The mothership may indeed conduct diligence checks on part serial numbers prior to approving such a claim. Your suggestion that dealers carry out ad-hoc warranty repair work, at their own expense, then say 'hey mothership, you owe me $x for warranty work this month' is frankly laughable.

Honda is charging around half the cost of a new generator for the inverter module alone, a part which seems to be frail and commonly fails. I view this as customer hostile pricing and the danger of that is creating hostile customers. Unfortunately, we are likely to see more of these high parts costs, as manufacturers respond to having the 'right to repair' legislation forced upon them in more jurisdictions.

<my reply #15>

If the dealer lets the consumer walk out of the shop with a new/repaired genny without warranty approval from the mothership, then they get to pay for an education. The warranty is backed by the oem not the dealership.

The potting compound used here to block repair efforts is like the old fashioned version of modern DRM. You've decided to bark up this tree, little doggy, but this forum is littered with DRM circumnavigation threads, which also dents the margins of manufactures and their dealers. In effect, theft, as you would say. So, you better go for walkies round the forum and get barking

<this reply>

[voltsandjolts]

@all,
So 'voltsandjolts' ...rant...flogged horsey...more rant...

Wow. Did all the toys get thrown out of your pram? Nothing like the fury of an old dealer scorned, eh? I fail to see how any experienced and diligent independent dealer would be left out of pocket, but if it worries anyone they could simply avoid going to an independent dealer.

Anyway, thanks for taking the time to diligently document my support for 'right to repair' and my anti-extortion stance

[t4796]

Same situation although mine looks damaged in a different way to yours. Did you make any progress?

Investigating replacing the module with one from the kipor honda copy.

[abdulbadii]

need to depot it, might be by acetone/ketone kin such as MEK

might usefull: https://maker.pro/forums/threads/potting-compound-removal.45049/

[RadioActive1983]

I made one back to life.
Extremely difficult job, but not impossible.
Need to use brutal force to extract inverter subboard.

[BradC]

I made one back to life.
Extremely difficult job, but not impossible.
Need to use brutal force to extract inverter subboard.

Wowza! What was the fault?

[RadioActive1983]

Some transistors was burned out.
Removed all of them and installed full set of brand new and most powerfull IGBT's I could find.
Tested with 2KW angle grinder for about 20 minutes.
No problems so far (3 months since repair).

[fmashockie]

have you tried dunking this in paint stripper,i think its methyle chloride?.

methylene chloride and dichloromethane are the same thing

It is also an aggressive carcinogen so please make sure you use proper PPE when using it!