I opened up the 7020, and found a cluster of 4
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1. orientation But the pictures I took before I ever got the solder iron hot show a wire going into the PCB right behind Q614 so I soldered the hookup wire into main PCB position M and listened to sweet music again for several hours last night Your suggestion to set SoftClipping Off led straight to the solution I must have accidentally pulled the wire while rooting around looking at parts and their orientation It may have been a partially bad solder joint since there s no sign of fracture on the end of the hookup wire I certainly didn t see it just hanging around though it must have been tucked behind something more or less out of sight not to be discovered until I removed the SoftClipping PCB I wonder if something like this isn t behind the distortion you see with your 3155 with SoftClipping ON a cold solder joint or a wire almost pulled out Just a thought But the music is best ever out of the 7020 Break in was a bit uncertain a bit too subdued at first but more coherency clarity and texture has emerged in the last three nights it s still very smooth overall I heard a new line in the bass Bach organ prelude that I ve never noticed before Thanks While I probably will go ahead and do the active XO biamp thing sometimes I feel drawn to the relative simplicity of a maxed out 7020 all by itself The music last How much difference in amplifier input sensitivity can the active XO compensate I assume th2. that way I can try a bazillion layouts check for hum etc Once I ve got a layout that I m sure works I ll build it on a 1 2 inch aluminum slab and put it in a ventilated box I m thinking about tucking them behind my speakers 1 5 foot speaker cables and 4 5 5 foot interconnects not too bad If I do that I will keep the AKSA boxes very plain maybe just a flat black box with a grille on the top What s the quietest way to do a power on light From Allen Wright You sent me a 7020 map Suggestions 1 You hi lited the Norm In section I d leave that alone and simply go in via the Lab input That bypasses all the filters but leaves the vital bias network intact But hard wire this connection at the PCB don t use that thick link at the rear panel sockets 2 Put circa 10nF 63V MKP bypass caps across ALL the elkos in the signalpath They will need to be small to fit and not get in the way too much There are LOTS of them so this will make a remarkable change Otherwise change all the coupling elkos to Blackgates but thats like goldplating the engine compartment of a Datsun 3 Biggest change I ever made to old NADs was to short out on the PCB EVERY switch I could find that wasn t ABSOLUTELY essential especially the stupid speaker selecting switches 4 Add lots of extra poweramp capacitance but only use hi freq caps intended for switch mode powersupplies Extra regular elkos loose as much sonics as they add Wire them
3. I think I ll stand them off the board since they are heating in normal use anything wrong with Radio Shack resistors How important is 180 ohms Michael Percy sells several 174 and 187 ohm within 3 3 and 3 9 of 180 resistors that are probably much better than stock All along my alternative to fixing the 7020 has been to put a Foreplay together and buy a power amp I can still do that but I find that I REALLY want to fix the 7020 instead Now that there s possible trouble I m surprised by how strongly I want to fix this little machine and make it sing Audio is irrational and they don t call it the Asylum casually I don t think Last night I replaced all of the busted and possibly busted parts in the right channel even numbered parts The left channel all odd numbered parts have not been changed since the little glow worm incident So after checking everything 72 times I plugged in the headphones and turned it on Both channels alive all functions functional The 7020 is not anywhere near healthy though After listening a few minutes to FM via a dipole I keep at my workbench I thought it sounded a bit fuzzy Before I was often thrilled with the sound of the 7020 with these headphones and this dipole but it might be a bad night for reception I hooked up some old very cheap speakers just to be sure that I wasn t going to fry my good ones and then moved out to the main system After listening 15 seconds to one of my reference CDs
4. in with foil rather than wire doesn t have to be silver and bring it RIGHT to the O P transistor connections 5 Trick diodes are a minot tweak for the reg supply but VITALLY needed to replace the output P S s bridge BD901 KBL02 Schottky s if you can find them otherwise fast soft ones with plenty of current reserves The 3020 7020s are inherently wonderfully musical devices pity they didn t make a really basic version with NO switches tone controls etc etc etc Hi Tweaking a 7020 was my first real audio project and I got lots of help from people on this board The tweaks that made the biggest difference in my system with the music I listen to etc were 1 Power supply diodes There is a large monolithic rectifier bridge by the four power supply caps I replaced that with four FRED diodes now you could use Schottys or Stealth diodes There is also a bridge in the regulated power supply on a seperate board Replacing those with FREDs greatly reduced grit and glare 2 Power supply and coupling caps I used Nichicon Muse and got more high end extension I also doubled the power supply capacitance and did not hear a large effect but I was using 94db efficient speakers at the time 3 I removed the Soft Clipping board You want to get a schematic before you do this because you can t just pull the board and be done with it it s been a while and the details are sketchy but a look at the schematic will make thin
5. it s obvious that I have major levels of distortion now Casual listeners might not notice some would but it s pretty bad nothing like the sound I had before I began the initial work on the 7020 and 10 million miles from where I was before I screwed up I haven t allowed the system to burn in maybe 30 minutes so far but the sound is so bad that full recovery from this would be the burn in story of all time The symptoms 1 Noticable distortion as soon as the music is complex for example when the full orchestra comes in in BOTH CHANNELS I ve tested this via the balance control not by just driving one channel not yet anyway 2 More hum and different hum in the phono section Before there was hum in phono but it was VERY low level Now it is noticably louder still not very loud though and there s an added component like a rapid beat frequency that makes the hum sound a bit like an engine running with a certain throatiness to the sound This leaves me wondering if I ve cooked part of the power supply distortion on both channels not just the one I worked on plus hum in phono Last night I found and fixed the source of the distortion in the 7020 I was looking at some dumb possibilities that lurked in my mind as possible causes things to eliminate before embarking on a full PCB sweep I had used a ton of heatsink grease on the big output transistors was that partially shorting them out I took them out cleaned up th
6. like 4700 2200 4 27600uf I might try the Schottkys I have they re rated at 290 amps nonrepetitive surge They re only 100 volts though I measured 60v across the AC so 60 1 414 85 volts do you think 100v is enough headroom What happens if one of those diodes blows I ordered an AKSA 55w standard issue Have you placed the order for the UG1O0DCT BY Q28E 200 rectifiers yet Just checkin Gotta scoot go home and play some tunes Hi Dave I spent the week listening to the 7020 with the soft clipping board removed the sound was extremely transparent and resolved After a few days I thought it might be too much of a good thing detail surgical and clinical worry worry worry so on Wed night I put the board back in and re wired it Two more days of listening is this more musical or what Nope it s more mushy way more mushy So Friday night I pulled the board again and I m definitely happier this way It s really a huge change I think I m going to pull the speaker switch and replace the speaker binding clips with the Cardas binding posts I bought long time ago I m getting tired of trying to jam all those free copper strands from my speaker wires into the clips I ll put some large spades on and fix that problem and pull some more wire out of the 7020 too I think I ll build the AKSA as monoblocks I ll build one side as a prototype on plywood with an aluminum cookie sheet screwed onto it
7. mods was shorting something anyway stereo FM was restored when I wiggled the front vertical PCB on the right side of the 7020 There are two small vertical boards held in place with a vertical clip that engages the two boards at the top and holds them so that the PCB connectors at the bottom engage The front board towards the front of the 7020 had been pushed out of the clip during all of the chassis flipping I did trying to find the right pads to de solder etc I m giving this to you in some detail so you will know the score if this happens to you In terms of sound things are still evolving First the hiss and hum I talked about last time are REALLY minor maybe I ve got something wrong with the headphone circuit since I did the original listening with phones Listening with my ear against the speaker drivers with the volume at full maximum I hear a slight sizzle from the tweeters a slight hum from the mids and the lows are quiet In the phono position with the volume at max I hear audible hum sounds like a mixture of 60 and some higher overtone 120 180 240 HZ This is definitely not audible at even very loud listening levels So we have fixed the 7020 I probably have less than 15 hours of burn in so the situation is still fluid The 7020 sounds pretty much like it did before after the initial hum had disappeared after warm up It does seem to be a bit cleaner here or there in the occasional passage I hear something a bit bet
8. I opened up the 7020 and found a cluster of 4 large blue caps diam approx inch each height approx 1 inch bundled together with a plastic tie Of the four two look like they have leaked brown stains on the PCB just below The leakers are C911 and C912 John Curl recommendation use Nichicon MUSE caps but I would like to understand the trade offs If I go too high with C what happens besides bigger and more expensive what s the impact on performance only downside is that when you turn the amp on the caps represent a short until they charge up turn on surge too much C and you pop fuses when you turn it on I generally use a 4x as big rule of thumb to avoid having to add circuitry to slow down the start up surge The 70 000 NAD i did was before i learned this but that unit is still chugging 15 years later and has never been a problem I opened up the 7020 last night to get an idea of how much room I have for those power supply caps guess what I found a few more leakers These guys have brown or black crispy crud lying in a puddle on the PCB or collected at the base of the cap It s not solder flux since the only components that have brown crud below them are light purple elelctrolytic caps just like the power supply caps we ve been working on I couldn t tell who the manufacturer is I don t have the viewing angle 4 2200uf 63v caps these will fit and exactly replace the exing caps 4 4700uf 63v
9. at I can put resistors or a pot in the XO for each amplifier from the service manual the input sensitivity for the 7020 high level is 30mv watt for the C270 it s 9 2mv watt Now the C270 advertises variable inputs but that would probably decrease its sensitivity I don t need to resolve this particular example right now but I do want to get an idea of how much difference in input sensitivity between amplifiers I can accommodate After I ve got the amplifier input sensitivities leveled out I still need some adjustment range to play with as I listen I thought I would take 30 mins last night and put in my Schottkys PS board I ll do the unregulated bridge later not so fast Sparkie The leads were too damn big to go through the PCB holes so I made lead extenders from a double run of 24ga copper and the spacing is tight so I used heatshrink in addition to the ceramic spacers to reduce the odds of shorts on and on and on a couple of hours of brain surgery when I d expected 30 minutes of cruising So I listened only for a few minutes last night The Schottkys seem to have provided more edge to the sound possibly at the expense of clarity I let the machine burn in overnight and this morning I listened for a few minutes it may have smoothed out some I m not sure The 7020 is running now and I ll listen more closely tonight should have 16 18 hours of burn in by then I will probably leave the Schottkys in for a month or
10. caps to be added outside of the two fuses mounted to the PCB This will reduce ESR effective series resistance give me flexibility if I need it and boost capacitance to 3 1x original levels DON T DO IT s 1 Here is the bit from David Klien The transistors are 25D733 and 2SB557 They are 30 amp types but their small signal behavior matches the original devices so no circuit changes are necessary I pored through transistor manuals at great length before finding these types They would be a perfect match for your souped up power supply even one Farad per channel won t help you if your output stage is in saturation I see a LOT of ceramic caps in the 7020 at some point I might want to replace most of those My planned potential mods to the 7020 are repair the unit to eliminate hum for all source switch positions beef up caps in power supply and output stages the stuff we ve been talking about for two months upgrade bridge diodes in the power supply Shottkys or FREDs still reading and learning about this replace the captive AC cord build J Risch AC Line Filter and Surge Supressot so all of the additional filtering would be outboard but I d have a 14 ga shielded cord to the 7020 I ll check for the proper line polarity before I solder the cord remove the spring loaded speaker terminals and replace it with good binding posts that take spades possibly replace the female RCAs with good
11. e mess and put them back in Fire up the machine this time with SoftClipping Off Hey sounds pretty good with headphones and FM dipole I think I ll take it out to the main system and listen for a while but let s look around some more With SoftClipping On there s a noticable volume drop and increase in distortion The 7020 didn t behave this way before the big screw up with SoftClipping On the music used to be sweet and clean So I removed the small SoftClipping PCB maybe a fried part on that board I looked at every part on the board for signs of excess heat or other trouble no clear evidence so I put it back and screwed it in place I ll work on this later Hell I can replace every part on the SoftClipping board for less than 10 Time to go test this thing on the main system But there s a big oh shit a 5 inch piece of white hook up wire that comes from the SoftClipping PCB is just hanging out there in space I must have broken it loose The wires coming from the SoftClipping board are letter coded and there are matching letters on the main PCB The free spirit wire comes from position M on the SoftClipping PCB AND there s an empty M location on the main PCB right next to Q614 Actually the empty M position has solder in the bottom of it s PCB hole and it s been that way for a while because I ve noticed the empty hole with solder in the bottom several times while I ve been looking at nearby parts and their
12. ew caps I was just trying to lay good groundwork before I beef up the PS caps so I think this is real not a psychology experiment Date Fri 17 Nov 2000 09 27 11 0600 The 7020 is sounding really really nice To date I ve replaced C911 914 and 95 of the electrolytics on the PS and all of the electrolytics on the phono board All jumpers on these two boards are now copper 22ga magnet wire on the PS board 24g teflon insulated wire on the phono board I ve replaced a few ceramic caps on the phono board with Wima polypropylene and a couple of the ceramics on the PS board with film caps I also replaced a few maybe 5 of the electrolytics in the preamp I had some extra caps the machine was open let s go I will work my way through the preamp and power amp stages over time The first thing I noticed was a significant decrease in graininess and glare in the sound I had never really heard graininess out of the 7020 but now the sound is smoother still I DID hear occasional glare in the upper midrange in the last 3 nights of listening I have heard none at all A few days ago the sound was smooth refined and maybe laid back too much In the last two nights the sound has become just a bit brighter that s good in this case at least so far it is both more detailed AND smoother equally capable of savagery and smooth seduction depending on the music Last night we had some people over and I was playing Keith Jarett s The Ni
13. ght The Music and You Last summer on Music Lane someone posted a question about the sonics of this CD I replied that it was one of my favorites but the sonics are subdued after all what do you expect from a solo piano specially modified for quiet playing played quietly Another poster commented that the sound of the piano on this CD became increasingly vibrant as he improved his system So last night after the people left I m reading the paper stewing about the Florida recount mess three glasses of wine into a very nice evening and NOT thinking about audio but damn that piano sounds WONDERFUL not totally there yet but clear evidence of significant progress I m very happy with the music in my house now and we re only 10 into the project Thanks again I can always tell when a change to my system has had positive sonic impact when a CD I ve listened to for 10 years which has always sounded good as in no complaints suddenly comes alive after a change When I went from straight Beleden 89259 Cardas GRMO interconnects to the Jon Risch recipe slightly modified it was Handel s Water Music and Vivaldi s The Four Seasons suddenly the low strings had bight the character the voice of each of the strings emerged and now I got the point the artistic vision of the composer musicians With this latest round of PS plus a few in the preamp cap upgrades it was my recording of Shubert s Unfinished Symphony that eme
14. gold plated Cardas or Vampire RCAs upgrade all caps in the power supply and along near the signal path Peter C901 470uf can t read the voltage C902 330 uf 35v I had to scrape the crud puddle away to read the number on the PCB for this one Dave Those are the input caps on the hi level power supply regulator board These are on a board sticking up from the main board just beside the power amp supply It You were dead right Last night when I replaced C902 the hum was gone there s still VERY low level hum from the phono section audible with the volume CRANKED and I rarely listen with the volume above the 10 o clock position There s a bit more hiss than I had with the leaky caps definitely not audible at listening volumes but there nontheless And we re not done with the surgery yet I still have four more caps C911 914 to replace I m intending to run color coded 12 ga solid copper wires out from the base of the caps I think it s 911 and 912 but I m at work and can t look to be sure to serve as a bus wire for the additional caps I ll install in a couple of weeks Does that sound OK Right now I m planning on mounting the addtional caps 4x4700uf 30x50mm to the vertical part of the large metal heat sink for the power transistors Sound OK but no stereo on FM what the hell Of course I thought that I might have bridged PCB foils with solder or a long lead I left a few to facilitate the next round of
15. gs clear I still have the 7020 it s in daily use by my wife who absolutely loves that little rig I love it too but she s got it so I ve been forced to build AKSA amps and Orions Peter Posted by PSP A on January 17 2006 at 12 20 37 In Reply to Re NAD 7020 mods posted by bjamesw on January 17 2006 at 11 05 10 I think only the electrolytic capacitors will get old I eventually replaced all of them but I didn t mess with those in the tuner section since I wasn t sure if I d screw up the tuner alignment I used Nichicon Muse very good and not extremely expensive There are a lot of steel jumpers most of them rusty I replaced those with teflon insulated 24awg solid core copper strands from Belden 1585A cat 5 wire I can t say that I heard a huge difference but steel and rust can t IMPROVE the sound You could also try nice film caps if they will fit for the coupling caps in the signal path that was on my tweaking list but my wife asked for the 7020 before I got all of that done The rectifier diodes will last forever unless abused but new technology diodes FREDs Schottkys etc sound very much smoother I noticed a huge difference here I think it was this change that gave me an inkling that tweaking really could bring major sonic improvement Stock the 7020 is very nice tweaked it s nicer still At one point I was using a Foreplay preamp to feed the 7020s amplifier section that was a big improveme
16. ing noises either Last night I cleaned the pins sockets some more with ProGold and things seem fixed for now I ll just have to wait and see for a while If that doesn t do it I wonder what the next step is Over the last 6 weeks or so I put in some Schottkys in the regulated bridge felt that they were super detailed and that there was a layer of grunge maybe newly audible because the Schottky s had removed a different layer of grunge So I put in the Harris FREDs 8A 600v Those sounded a lot nicer much more musical But there s still a grunge layer loss of clarity in complex passages Massed strings get fuzzy at fairly moderate levels And then there s the start up thump with lab in but not with normal in You suggested that I pull the soft clipping board So I worked out the signal traces and the jumper wires checked things out with a VOM and cranked up the solder iron First thing I see is a bad solder joint for jumper I at the main PCB a small crack in the solder source of grunge I don t know I just pulled the damn board soldered in new R701 and 702 sounds very very nice Grunge mostly gone The start up thump is still there though I might start tracking that down by replacing C601 and 602 Next is to upgrade the unregulated bridge I saw a post on AA recommending a filter cap maximum of 10 000uf per 100 amps of surge current capacity in the diodes to cover startup and I want to add something
17. nt For 25 you have done extremely well Tweak slowly listen as you go Some tweaks that everybody recommends will likely have no effect to your ears or sound worse Enjoy the journey Change the volume pot for a good unit like the alps blue I swapped out the vol pot of a 3020 for a conductive plastic type from bournes The result was that the archetypal warm laid back sound disappeared replaced with a full fast clean dynamic one This was a complete suprise as I had no idea that the vol pot was going to have such a huge influance on the sound The smallest cap will also be better at shorting RF noise
18. rged from the haze the smoothness yet with clarity and definition of the sound in this recording is incredible now Now it is emotionally engaging before it was at some level background music I had to work to stay with it now it grabs me Then I put on some Bach organ and got a surprise significantly more and significantly better defined bass WTH I might have expected more clarity from less distortion from upgrading the PS caps but I don t understand where more bass came from so far I have made no changes to the stock circuit just put better caps in Date Wed 22 Nov 2000 08 44 51 0600 Subject Re Schottky shopping lt lt Let it burn in but this is where the previous comment about upsetting the regulator might play gt gt It sounded a lot better last night I will just listen for a few days After Thanksgiving and the parties the kids will have they re home until Sunday night the 7020 will be WELL burned in Next week when it s quiet again I ll listen HARD If there s any doubt I ll remove the added caps for a quick A B test I think the 7020 has become a very fine component smooth and quite resolving it s a delight to listen to It is also becoming increasingly sensitive to getting temporarily screwed up as new parts burn in It will probably be a standard thing the machine will loose focus for a few days after each change When I did the first round of cap fixes and replacements the improvement
19. ruptions blah blah blah I just screwed up because I wouldn t take the time required to figure it out Later in the evening after the smoke had cleared I figured out how I could have done this right I had Q611 to look at the pin configuration is in the schematic pin E is called out on the board and I have photographs that I took before I started you should have seen me studying those photos with a bright light and a magnifying glass like a spook looking at satellite photos of an enemy airbase and after an hour of careful study I figured it out Too damn late though So I put on the headphones plugged it in and turned it on Huge hum and no signal from the right channel apparently OK from the left Power off in less than 5 seconds Then I looked for a solder bridge etc de soldered and cleaned up a potentially offending fillet and tried it again Same story This time I tried a few different sources dumb this is the power supply I m working on and while I was doing that I noticed a glow from the PCB Instant power off the glow dies a wisp of smoke and shit for brains The little glow worm was R646 listed at 180 ohms Its partner R645 is marked brown gray brown gold 181 ohms 5 and by the way the board looks toasted old toast though on this side too I pulled R646 and it measures approx 80 ohms now but has obviously been fried So I ll look for a couple of 180 ohm resistors I ll get 1 2 watt and
20. se on the back of the 7020 chassis too I m going to let these caps burn in for a while then I ll beef up the PS and filter caps as we ve discussed long ago now While these are burning in I think I ll re do the power cord as follows I m going to start with a Volex Belden 14 ga shielded 3 wire cord approx 10 feet long I ll cut off the IEC plug then strip the insulation off somewhere in the middle of the cord and build a Jon Risch AC line filter around the cord The cord then continues into the 7020 where after I figure out the correct polarity I ll solder it in I plan to build this so the AC cord wires are never cut between the 3 prong plug and the 7020 so there s only one connection and that s at the wall a Leviton industrial grade socket I haven t tracked down hospital grade yet I will probably tap off a duplex outlet so I can also filter low power stuff like the powered FM antenna and for now the CDP eventually it will have it s own filter Date Tue 14 Nov 2000 10 51 54 0600 Subject cap questions I m still in early burn in 10 hours for all the electrolytic caps I ve replaced in the power IE so things will continue to evolve My early impressions are that the sound is less grainy now it wasn t very grainy before but I think it s smoother now There s still plenty of shine in the strings and growl in the string bass though By the way I really didn t have any idea WHAT to expect with the n
21. ter than I have before Nothing dramatic but the differences I DO hear are for the better I guess that s what I d expect for getting the machine back to its initial designed parameters albeit with better capacitors in a few key places None of the other similar caps in the 7020 shows similar signs but some are buried too deeply to see well but I wonder if some of the others aren t on shaky ground as well Last night was Power Supply night at our house The 7020 s power supply PCB came out smoothly encouraged a bit for starters with a little prying action using an offset screwdriver long L shaped and perfect under the edge of the PCB I just went slow and looked for small gradual movement The PCB was out in less than a minute There were 4 wires from the harness soldered onto the board so I tagged those and removed them replaced all but two for those I didn t get the right part it was hard to read the values without removing the board of the electrolytic caps with Nichicon muse of equal or higher voltage rating I replaced the steel jumpers with 24 ga teflon insulated copper Belden Cat 5strands replaced two ceramic caps soldered to the foil side of the PCB with metallized polypropylene caps Multicap PPMFX Michael Percy I cleaned the PCB mounting socket pins and receptacles with DeToxit and 5 ProGold I also treated the fuses and fuse holders in the same way I need to remember to treat the main fu
22. two then swap in some Harris FREDS see what I like best The Schottkys I bought from Digi key part no 50SQ 100 ND 100v 5amps in DO 204 package looks like a fat resistor I opened up the 7020 last night The distortion was due to an intermittent disconnection between the PS pcb and the main board Wiggle the PS board and it sounds fine A few weeks ago I was probing around on the back side of the main PCB with a voltmeter looking for the voltage across the unregulated diode bridge When I touched the foils I heard headphones scratching noises and the sound changed character becoming fuller or more thin as I poked around During normal listening I had heard occasional spontaneous crackling I thought that one of my new capacitors might be bad but which one horrible thought Also sometimes the sound was less involving but the fault was hard to put a finger on maybe I m just not in the mood to listen tonight The sound shouldn t change as I probe the board so I probed some more and eventually concluded that the problem lay with the connectors pins between the PS and the main boards I posted at AA looking for suggestions got stony silence the atmosphere there is sometimes a bit rarified for my taste and eventually re soldered all of the pin and socket connections on the two boards Problem apparently solved because the machine now sounded great no matter how much I wiggled the PS board No scratch
23. was so stark that better was obvious parts burned in or not Now I will have to wait to be sure the cost of progress I guess Date Mon 27 Nov 2000 09 07 17 0600 Subject Re eBay 7020 I went back to 1x on C901 902 last night Burn in progress had stalled out and it did not sound good With these caps doubled up there was a loss of clarity most obvious in complex orchestral passages also in multi voiced pipe organ passages the transparency that I had found just 10 days ago was gone It sounded a bit like the 7020 couldn t quite keep up with the music So I pulled the extra caps and sweetness reigns again Last night I was going to replace a lot of crappy steel jumpers etc and I thought I d start by replacing a large stranded white insulated jumper in the absolute northwest corner of the main PCB with 20ga solid copper I de soldered the wrong pad this is only the second time that has happened in the hundreds of leads I ve de soldered by now and I got one of the pads for Q612 Worse a section of the copper foil pad came up with the soldering wick it must have been broken off long ago and held in place by the solder fillet No problem there is an unused hole on the same foil section so I ll just solder it there So I pulled Q612 and screwed up the orientation when I put it back in In my defence it s a dark corner back there and the Q612 pins were pretty twisted so right way was non obvious There were inter
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