Oh dear.
Do your indicators still work? Does your 5 change lanes of it’s own accord?
Does it pull out of junctions without warning?
Does it head straight for M & S disabled parking spaces?
My stereotypical image of Scottishfiver as he typed the stereotypical comment above;
A yes…steriotyping…
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Hi guys,
Seems that I am in the same boat here. Currently own a MK3 with an NH61-66-920 amp.
When we originally bought it from the dealer about 5 months ago, assumed that this was simply the head unit and that it would just need replacing, was unaware of the amp being this common problem.
So in the process of contacting the Bose Repair guys in Edin. I thought it would be helpful simply to document and cover my experience with this for anyone in the future.
In the car I can get sound from the stereo, but it often just clips or drops like a CD skipping. The whole actual head unit is brand new I decided to replace out the existing default set for a clean new setup.
Previously it was not working at all no sound, we decided to just give the amp itself a little tap, and this started the sound up but its clearly still having issues so will let you know future results.
As I guessed would happen, the daughters amp has been sitting on the top shelf of my cupboard since I removed it 4 months ago.
I’m not paying to have it repaired as I’ll never see my money back.
So last night, I decided to open it up and take a peek inside, where I found 3 capacitors, one of which is ever so slightly bulging.
My electronics knowledge isn’t scientific, but I do know that a tell tale sign of a failing capictor will be noticable with a bulge.
I identified the caps as Nichicon RZ(M) type, (URZ1E222MHD1TN) so set about trying to find some, which eventually lead me to a web site in German, and guess what it was discussing…
The Bose/Mazda amp. https://www.motor-talk.de/forum/bose-sound-system-ausfall-nach-5-6-jahren-t4996052.html
Google translate would indicate that the poster is talking about the cause of the issue being the Nichicon capacitors os a common failure and that they are hard to come by, so he replaced them with Panasonic ones, and it’s been working ever since.
I now have 3 x Panasonic capacitors on order, and will report back my findings.
£3.50 for 3 capacitors is cheaper than £160 for a repair.
Interesting link. Looking a little closer at the German link it’s important to make sure you get replacement capacitors that physically fit. They say there is 23mm of clearance so don’t fit anything taller than 20mm. In practice a common size is 13mm diameter and 21mm high. These should be fine.
The capacitors originally fitted are 2200uF, 25v, 20%. Perfectly acceptable to fit a higher voltage but higher voltage ones will probably be physically bigger. The 20% figure indicates that the value may vary by up to plus or minus 20% from the stated value. Anything less just indicates better quality and less variation.
So to recap here is what you need.
Value 2200uF
Voltage 25v or higher
Tolerance 20% or lower
Height under 23mm
They are so cheap that even if only one is showing bulging best to replace all three in one go.
Make sure you know which is the positive and negative on the existing ones before removal and check the markings on the board. They will work if installed the wrong way round but won’t last five minutes. It’s not unknown for them to be incorrectly fitted by manufacturers but wouldn’t expect that with Bose. Stranger things have happened though.
I was already aware of the polarity, but better to mention it in case anyone else attempts a repair.
I measured inside the casing and also found 23mm space, The Nichicon capacitors are only 15mm, the Panasonic ones I found are 20mm, so will just fit.
and I agree on replacing all three, it makes sense while its apart.
Update:
The capacitors were fitted on Sunday evening, with the amp refitted last night.
It worked when I fitted it, however, i’m not yet counting this as a complete success, as the fault was a little intermittant to start with.
Maybe a few weeks will tell.
Nicely done - you are a braver and handier man than me
Fingers crossed that you have a permanent fix there; ours popped and banged intermittently, then gave up the ghost permanently.
what did you do, as if my fix works, then it’s really cheap and not difficult to do.
As per earlier in this thread, the previous owner had Bose Repair Experts in Edinburgh undertake a repair in July 2016. Despite their warranty Ts & Cs stating that the lifetime warranty for their repairs are not transferable, the company honoured the warranty and fixed it FOC. The previous repair was in completed in a period where (according to their Facebook feed and what the chap told me when I attended their shop) they suffered a number of failed repairs caused by a batch of sub-standard components and so had completed a number of warranty repairs on work originally done in mid-2016.
If you consider your work to be a permanent repair you should complete a write-up and post it on here. I for one would be interested to read it; I considered it to be a major technical achievement to unplug and unbolt the amplifier without the car bursting into flames; as far as I am concerned electronics is magic with diagrams…
I might just do a write up, although I’m not sure where the amp is in an MX5, ours was a Mazda 3, where it’s under the seat.
And I won’t be opening it back up again to photograph, so I’d probably pinch a few google pictures.
I wonder if the repair company used the genuine Nichicon capacitors.
I assume as they state they reverse engineered it, that they fitted some other size or manufacturer.
The fault re-ocurred 
I just wanted to add an update on my situation from what I posted a month ago -
I was basically very busy and had not got around to finding time to take the amp out, and get it sent. Also it was basically working to a relative degree, with just the odd times where sound
would drop out or it sounded like a bad connection but it was tolerable. That changed this week when I went to get in the car turned the ignition and immediately was blasted with a loud repeated popping sound through the speakers, extremely loud you couldn’t possibly drive with it, turning off the stereo in the head unit itself did nothing so I had no choice but to disconnect the amp.
I am basically at a situation now where it has to be sent off as I had wanted to do anyway - so today its been arranged for collection. Spoke to the guys at Edin. Bose repairs and they said
they’d be able to fix it over the Xmas period obviously with days allowing for holiday as per.
So that’s where I’m at right now, will be interesting to see when I get it back considering this is over the Xmas period.
Will update as and when it’s returned
Okay so to update - the contact I had with https://boserepairexperts.eu/ was very good. Contacted them briefly prior to shipping to ensure they had the order etc
all confirmed clearly - UPS collected the unit on the 21st December - the guy at BRE said if it arrived they may be able to work on it around the xmas period. However there was a delay not with BRE but with UPS no surprise.
So they basically attempted and were simultaneously unable to deliver the unit until the 3rd of Jan, I called BRE on the 3rd - to ensure they had received delivery - was informed they would work on the unit on the Friday - test it and send for delivery today Monday.
Well here it is arrived on Monday - straight back into the car - all working perfectly.
Great service apart from UPS - tested the unit for about an hour no issues - will update if anything changes but right now seems sorted.
Hiya, Just wondering if you got this resolved at all? As you’ve probably guessed, my Bose amp has gone on the blink. Really loud gunfire type noise and cutting in and out intermiittently, Sunday morning and it gave up completely! I may just have to send it off for the full repair but was wondering about getting a trio of capacitors that have been mentioned.
Barrie
I replaced the capicitors in ours, but it made no difference, so I put the old ones back in.
It’s still sitting in a carrier bag on the top of my wardrobe, it’s obviously not a prioirity to her, and I’m not funding the repair.
I can’t imagine it will ever get fixed.
I’ve heard been good results from the company in Scotland
Hi and thankyou for the prompt reply Yes, it looks like the Bose repair guys next. Everything I’ve read about them is positive so after the hols, I’ll be taking the amp out and sending it on to them I think. Had a search around but all the 2nd hand units I’ve found are two plug from the earlier models, after the first facelift, they’re 3 plug and non available
Barrie