A Story About Getting Electronics Repaired Professionally....
It all started with a pile of high-end hi-fi gear that, despite being 7 or more years old, are for the most part still worth fixing.
Except there comes a point when you have to ask: "Should I still keep spending money on it, or get it fixed properly".
Now, I'm not an electronics engineer by trade. Sure, I'll fix a cracked joint, or disconnect through-hole components and test them one at a time if I have to.... but things get a lot more challenging to me when things start using SMD (surface mounted device) componentry that I'm simply not geared up for.
So when I had two AV receivers die, two subwoofers that I've repaired several times (usually swapping capacitors over), and had repaired professionally at least three times each, (when more serious stuff that needs a proper service manual and fancy equipment to fix) So I broke down and took it in to be professionally looked at.
So in the end I took in:
- Marantz SR6005 AV receiver (protection mode, turns itself off).
- Anthem MRX 1120 (protection mode)
- Paradigm Studio Sub 12 (v5) Plate amplifier doesn't turn on.
- Paradigm Studio Sub 15 (v5) Plate Amplifier doesn't turn on.
The professional repair shop experience....
So I took the gear into the shop, got them all checked in and told the people there the symptoms that seem to be plaguing each piece of equipment. I paid the $160 (each item) inspection free, which would get deducted from any repair prices after the fact.
During this time at the shop I asked this exact question:
"I don't want optimistic estimates, how long will it take you to inspect this gear in realistic terms, there's no wrong answer but make sure it's accurate".
The answer was "Four business days per item".
Two full weeks rolled by and I'd heard nothing. So I called them up... "yeah we'll get back to you".
Another two weeks roll by, I've called a couple of times, and Ren's dropped into the shop to check progress since her work takes her past fairly regularly.
"Oh yeah the Marantz is completely unfixable, it needs parts that we can't get".
That's basically a month, and only one item had a report, and it was a very expensive "sorry we can't fix it".
Ok, it had some liquid damage, and it didn't shock me that it had corroded. I wasn't happy about it, but at least I knew where I stood.
Another week and a half goes by, and my Anthem 1120 has finally been checked... the prognosis:
"Yeah we couldn't find anything wrong with it. come pick it up".
Wait, what? You had it for well over a month and couldn't tell me it was working sooner than that?
However, in the week after I dropped all this gear off at the shop, another of my AV receivers developed a problem...
So I basically took the Anthem 1120 back, and dropped the 710 off. Another $160 inspection fee.
So I do that, and the 1120 has stopped malfunctioning... and I'm pleased that it works, but they never found the problem, and it has a couple of quirks that don't inspire long-term confidence.
Another 2 weeks later, I get a call, and they say "We can't fix the 710, can't get parts". So I took it back with no HDMI inputs.. which is hard since that's the only way it will operate 7 discrete channels.
So at this point... they've fixed absolutely nothing so far and we still hadn't heard about what on Earth was going on with the subs. They kept saying "we're making no promises"
Over these months, things looked increasingly grim. I replaced the Marantz receiver with a new one. The 1120 is working, although with some... quirks. The 710's non-HDMI inputs work (so only sound can work), but with an external DAC, I can get 5.1 channels working, which is enough for now. But make no mistake, this is a work-around.
So I had a conversation with Ren, who'd been visiting the store, and I had be chatting over the phone... and we discussed our "confidence level in this repair shop".
The consensus:
It wasn't good. The completely botched time line, the complete failure to inspire any sort of confidence. There's absolutely no real indication that this shop has done anything, no transparency, no photos showing progress or testing..... From my standpoint, I'd just spent $800 on what was effectively... nothing.
Let's say that they do manage to repair my sub amps....
It's a flight of fancy, I'll grant you... This repair, if successful and if history is a guide... I can expect it to work for at least 3 months, then the whine will reappear, and I'll get maybe another 18-26 months of actual use out of it before we're back here.
The lead up to my own solution...
To save my back, I still had the 15" subwoofer at home, still installed in the chassis. I sent the lighter 12" sub in it's entireity to the shop for testing purposes, and because the amps from the 12" and 15" subs are identical, I only sent the 15" sub's plate amplifier with it.
Let's fix the sub here my way, and compare results.
It was about 4am when I decided to do this. It's not normally the best decision-making time (there's a reason late night television has telemarking going on). I wasn't looking for a new amplifier (at least, not yet) but something much more useful.
The immediate problem:
You see Paradigm makes it's own speakers, completely in house, and exclusively for it's own products. There's no publicly-downloadable spec sheet on these proprietary speakers. When amps blow up, sometimes they damage the speakers...
So basically, I had no idea if the speakers were still good, what the normal specifications were if they were good, what the various specs of my subwoofer speaker currently look like, or what sort of amplifier or wiring arrangement would make it work well.
In short, I knew nothing! Except from the promotional materials that Paradigm had for this series, and (despite being highly idealised) I had a ball-park figure of what kind of Wattage this speaker could (theoretically) handle.
Testing needs to be done the right way...
What makes it worse, is that beyond DC resistance checks and literally inspecting/sniffing the speaker... I had no real way to see how signal frequency impacted impedence, I had no idea about the various mechanical/electrical properties of the speaker, other than if I could move it back/forth smoothly enough.
So I bought test equipment that might seem expensive for a one-off task, but it could literally save me thousands from avoiding potential damage.
I ordered a Dayton Audio DATS V3 speaker tester. It was a godsend. I plugged it into my laptop, connected the speaker to the terminals (after calibration of course) and found out the overwhelming majority of those specifications that Paradigm had never shared.
Knowing that the speakers were good, that they had parameters that were "within expected ranges", and having a plotted graph of the entire impedence curve meant that I could now see what sort of amplifier was needed.
Getting advice is always handy...
I reached out to a pro audio technician and asked point blank: "Here's my subwoofer's impedence curve, I'm thinking about getting a replacement amplifier for it, here are the ones I'm thinking about, is these ok? Or, have I gone off the track?"
The tech discouraged the cheaper option due to availability, reliability issues (I don't need any more unreliable amps) and electrical load handling. So I ended up getting a Yamaha (a brand I'm familiar with) amp and the signal booster to connect my receiver to this amp.
Wiring it all up was a breeze, I built a new back plate with speaker terminals, sealed the enclosure as it was, then connected everything up.
I'd spent a total of $1954 (1409 on the amp, $273 on the test gear, $162 on the signal converter, $30 on cabling, and $80 on fancy speaker posts (terminals). Throw in some scrap MDF for the back plate, some heat shrink, solder, thick speaker wire and other crimp connectors. We're still under $2000
It not only works, but works really well!
Best bit of all? That amp can run both subs from the one unit, and includes all mods for the second sub. Converting the second sub is completely free from this point.
....Back to the shop
Fast forward another two weeks from getting the partially working 710 receiver back... and I get a call. They tell me "hey we finally got the manufacturer's service manual, and we'll look at the repair, but we want you to pay $500 additional per unit, and there's no guarantees that we can fix it.
I've paid $800 already, they haven't come up with one single clear solution for any of it. They still haven't told me what's wrong with the subs (they know there's the inspection report part of that the "inspection fee" should include, right?) They want me to pay another $1000 with no guarantees of success, and if there's success the warranty is 60 days long.