Can anyone fix a Lexicon RV-8 for audiodon?

Thanks, timmage89. I just sent a message to the seller.

As you may have read in my earlier post(s), I was told by an authorized Lexicon repair person that the power supplies overheat and then fail with the 5VDC supply going very high and taking out chips on multiple boards. He said that no spares are available and that these units are essentially unrepairable.

However, a poster on this thread bought a parts unit and was able to fix his RV-8 by swapping in the main board. Maybe that magic could strike twice.

Thanks for the lead.
 
LexDM3. Did you contact the seller in Minnie? I am having what appears to be the same problem with my RV-8. Just happened three days ago and I thought it was now nothing more than a glorified boat anchor, it's certainly heavy enough to be one. Found this thread and am exited that it may just be possible to resurect my beloved RV-8. I know in the Craigslist ad it mentions cash upon pick up only. If it is really something as simple as replacing the control board that would be fantastic. Now, I just need to locate a control board and then find someone local to me, Southern Ontario, Canada who can install it for me. I would very much love having a working RV-8 again as I find no all in one modern AVR can match it in sound quality. Thanks for this thread and a spark of hope.

P.S. Any idea when or if the recently announced new Lexicon AVR's will be available to purchase?
 
After finishing repairing my RV8 for the God knows how many th time, I can tell you that the posts I've read are barking up the wrong tree. The problem is not electronic with these units, it's mechanical and relates to the poor quality connectors Lexicon used in the units. The ribbon connectors for instance are not terminated at all, and simply press into the slots on the board. Over time tarnishing results in higher resistance and they need to be pulled cleaned and reinserted. Similar with the plastic ones as well which are just the usual computer types and I'm not sure they're designed for 10+ years use without maintenance.

The ones which seem to be most important, and which I go for first are the molex from the SMPS (both ends of this need cleaned) power into the SMPS, and don't forget these connectors are locked with a plastic clip. The black power ones to the amps got a clean this time, and also the long ribbon cable which attaches to the top circuit board which always appears to cause the most issues.

Do not pull all these connectors off at once ! There are a lot of them and you can easily get them mixed up. Also there are connectors which are difficult to access so again don't pull them off unless you know you can get the things back in place again. Once you are familiar with reinserting these it's fairly simple, so pick an easily accessible one to practice on first.

Use a switch cleaner to help remove any tarnish and it's even better if it's a cleaner with lube which will stop it happening as quickly. Alas once these things begin to tarnish it's like a car beginning to rust. Everything should work fine for maybe a couple of years, but you will have to revisit it and do it all again - I can't see a way around this unless you fancy replacing wiring looms connectors and ribbon cables.

Mine would either fail to reach standby constantly cycling with all three LEDs on the front lit, occasionally it would get through the start up and then drop out again, and other times it would frustratingly work for 10 minutes and then fail! After the service above, it's just run playing loud for two hours without any glitch, fingers crossed I'll not have to pull it apart again for another couple of years !
 
Thanks! That's great information. I bought the one from Minnesota a while back. When it arrived, I immediately changed the power supply and to my amazement it came right up and works fine.

I'll try the contact cleaning routine on the other one and I'll clean them on the good one too. I'll be selling at least one of them and both if I can get the first one working so let me know if anyone wants to buy one. They are incredibly good when they're up and running. Don's kids left his turned on 24/7. It was an early version without a PS fan and that caused the PS to fail. I think it will be fine with a new PS and a fan to keep it happy if I get it going.
 
As an update, the switch cleaner brought it all back to life, and I could get maybe 45 minutes out of it before it started to fail again, and would then only recover for a few minutes. The white connector on the SMPS was discoloured brown in places, so I took it off and use a pencil rubber (eraser if you're in the states), it was so tarnished it turned the rubber black, but now it's back working as it should.

I do wonder if the 'failures' of the SMPS are not failures at all, as measuring voltages on the board will be incorrect as a result of the pins going high resistance. A new power supply will appear to fix the problem because it will clean the pins to some extent.
 
Thanks, Flake.

For what it's worth, I'm very sure that there is also a failing power supply issue on these. On the first one I looked at (which still doesn't boot up), the +5V output on the 3 output switching supply was about 3.2V. When I subbed in an external 5V supply, the symptoms remained the same. When I replaced the switching supply with a new one, it still didn't boot up. I suspect that some of the connector problems you found may be contributing to that and I'll check that out. I checked voltages across the boards and they were consistent.

BTW, I pulled the SMPS out of that unit, put a resistive load on each of the outputs calculated to run the supply in the middle of its output ratings and tested it. The +/- 15V outputs were fine, the +5V was still way off. So I have no doubt that the SMPS's are failing and the tech at Pyramid Audio, an authorized Harman/Lexicon service agency, confirmed that. I bought the two new supplies from them.

The second non-working unit I bought came right up after I swapped in a new power supply. I didn't even try it before I swapped supplies since I had a new PS on hand. Based on your findings, I'll clean all of the connections in that one as well.

Thanks again!
 
I originally followed the defective SMPS route the first time it failed, and there is a small electronics / computer shop nearby with facilities to rework surface mount boards. The SMPS checked out fine, but if it hadn't then it is quite an easy board to fix, which given the seeming shortage of replacements might help a few people. I believe the early problems were capacitors leaking rather than the active components, and techs working for Lexicon used to replace them with new ones to keep machines running.
 
FWIW, my one experience with a Lexicon of this vintage led me to believe that they were victims of https://en.wikipedia.org/wiki/Capacitor_plague - at least, my example appeared to be cured by replacing the electrolytics on the P/S board. (I don't recall whether I also re-seated connectors along the way and perhaps cleared up some symptoms just because of that. Could be.)

Cheers,

chazix
 
This has been an incredibly informative thread. I have been tied down with other projects and haven’t been able to get back to Don’s RV-8 that started this thread but I plan to do that soon.

I will be helped considerably by all of your great experience and information. Of course, now having a second and working RV-8 on hand to look at should help too.

Thanks!
 
When I last removed the PowDec SMPS the capacitors were all Rubycon - a decent brand unaffected by the plague, so I do wonder if these have been swapped by a previous owner? It's difficult to see the branding on the data sheets, but were Rubycon the original components?

The Bootrom on the Lexicon says 2003 so it perhaps missed the capacitor plague?
 
since this is one of the few threads I can find about the RV 8, I thought i would post here. I have come across one for sale..."as-is" says it needs a firmware update. it should work even without the update should it not? it is listed a s a final sale from a place that usually gives a 30 day warranty.. I don't care if it has the latest features that may be available through the update. I would be happy using it as a 2 channel if I can get by without the update. I can probably get it for a couple hundred bucks.... should I risk it??
 
Great thread! I recently bought one of these beasts, and it would show an error light after about an hour after turning on. Sound would cut out and fan would turn on erratically. I found the recommendation here to clean and reseat all the ribbon cables. Did it, and now it's working great and sounding fantastic! Much better than a boat anchor :banana:.
 
Hey absolve2525, can you share your method for cleaning and reseating those ribbon cables? I bought the RV-8 today. It is playing now but I am told that there has been an issue with it playing for several hours and then stopping. unplug/turn off and "reset" and then it plays again. hoping it is as simple as cleaning some cables....
 
My cables were actually pretty clean. There are some recommendations in this thread, but I used alcohol to clean them. I think the perhaps one of the cables may have been inserted improperly at some point, which is easy to do with the thin cables and small insert type connectors. Pulling, cleaning, and reinserting the cables carefully so they're all lined up with the connectors, is the first thing I'd try as suggested here. I measured the bias on all channels all afterward, and they were all spot on. Good luck, hopefully it's an easy fix.
 
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Check to see if your "new" RV-8 has a cooling fan on the switching power supply (SPS). It is located on the left side of the unit as you look at it from the front, not too far back along the left side. The early units didn't but they added it somewhere along the line, likely to reduce SPS failures.

You should hear the SPS fan running all the time if it's there and the rear panel power switch is on. The power amp heat sinks also have cooling fans but those shouldn't run unless the unit is active.

If it doesn't have the SPS fan, you might want to add it if you're comfortable doing that. There is a small bracket that bolts to the power supply to attach the fan but you could probably make something like it pretty easily.

Lexicon designed the RV-8 to have the switching supply and a lot of the logic powered up all the time if the the rear panel switch is on. That allows it to respond if you use the remote to turn it on but it also means that the SPS and much of the circuitry runs forever unless you turn off the rear panel switch. Not a great idea in my opinion. I'd be inclined to completely turn the unit off between listening sessions to reduce the "mileage" on the power supply and boards. As you may have read in this thread, replacement boards are no longer available so make 'em last!
 
I will use the rear switch from now on, so it's not drawing power when not in use. Do you have any more details on that that add-on power supply fan, such as where to connect it and what type, and where it should go exactly? A photo would be immensely helpful, if you happen to have one. Thanks!!
 
My unit does have the fan. I can hear it with unit off but rear switch on. I guess I will power down completely from now on in an attempt to prolong this sweet sounding machine.
Dilemma now is whether I should leave it be or have my tech poke around and check caps or if I should attempt that ribbon cable cleaning.
 
The ribbon cables aren't too hard to access. There are a couple tricky ones attached on each side of the amp sections, that are bent to fit at an angle, but not too bad. You'll have to take top and bottom off to access all of the cables. I will have to double check and see if mine has the rear fan. It does have the amp fans.
 
Okkk now I see where there is a power supply fan, after Googling for photos. Here is mine from side view, without the fan. Then there is a Google photo showing overhead view with fan attached on the left. I do have some small computer fans, just not sure where to connect it for power. If anyone can instruct where to hook it up, I'd love to know. Fan blowing towards it or away? Thanks!
 

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