spritzer Posted January 25, 2011 Report Posted January 25, 2011 I've never had any issues with removing soldered heat sinks but it is a good idea to just solder one of the pins until you are sure the bloody thing works. Also screws facing in opposite directions is sound advice.
Looser101 Posted January 25, 2011 Report Posted January 25, 2011 Hey Kevin, found these couplers, in case you are still looking. They also have a complete shaft with couplers. Scroll to the bottom of the page... Shaft extensions 1
livewire Posted January 31, 2011 Report Posted January 31, 2011 Mouser repair parts order just arrived. Will this kgsshv psu ever work right again? Stay tuned, progress report manana.
livewire Posted February 2, 2011 Report Posted February 2, 2011 Welp, I promised a progress report, but so far there is no progress. The first time I had originally ordered parts for the kgsshv, there was no BOM. I went off of the board silk drawing. This time I used the latest BOM. I found a mistake after receiving the parts for the repair this time around. The part listed on the BOM as FQP8N80C should read FQPF8N80C. So the regular TO220 with the exposed metal tab were shipped, they should be the all plastic jobbies. Hello Mouser! (again)
livewire Posted February 2, 2011 Report Posted February 2, 2011 I guess that I could use the TO220 sand with my raised heatsink kludge. But KG said "please dont do it that way" so I'm not gonna this time. Gee, I'm a patient guy.
nattonrice Posted February 3, 2011 Report Posted February 3, 2011 (edited) If you angle the pins back a tad you couldn't use the 8n80c's you've got with an Al oxide insulator and nylon bolt (f you have these already)? Edited February 3, 2011 by nattonrice
livewire Posted February 4, 2011 Report Posted February 4, 2011 That thought crossed my mind but I dont have any extra oxide insulators and I wont use plastic screws. Craig Sawyers had a good idea using extra long flanged insulator washers along with stainless screws coupled with the oxide insulator "tombstones". I bought those(oxide plates and long shoulder washers)the last time around to re-do the small kludged (raised) heatsinks that KG didn't approve of. I should have bought extras, but did not. So I am going to reorder again and do it the right way. It's not expensive, so I dont care. Hey Doc, if yer reading this please update the BOM. Thanks!
Craig Sawyers Posted February 4, 2011 Report Posted February 4, 2011 Craig Sawyers had a good idea using extra long flanged insulator washers I can't claim that long bush idea was mine - Inu tracked those down as part of his T2 build. He used plastic screws as well, but the fact that the bush goes almost all the way through the alumina insulator means that steel fasteners work perfectly. Only thing to watch is that although the outer diameter of the bush *should* fit in a TO220 hole, tolerance stack up sometimes means that it is a very tight interference fit. Feel the force, kgsshv buider, feel the force. Believe it will go in and it will.
kevin gilmore Posted February 4, 2011 Author Report Posted February 4, 2011 (edited) updated spreadsheet. if there are any other errors let me know. fqpf8n80c... lots in stock at future electronics. If you want to be fancy about it, on the small heatsinks, remove the pins, use them upside down, thread the area on the other side where the pins used to be, and then drill and tap a new #4-40 hole for the transistor. Use ceramic insulator, bushing and stainless screw. Edited February 4, 2011 by kevin gilmore
livewire Posted February 5, 2011 Report Posted February 5, 2011 (edited) I can't claim that long bush idea was mine - Inu tracked those down as part of his T2 build. He used plastic screws as well, but the fact that the bush goes almost all the way through the alumina insulator means that steel fasteners work perfectly. Only thing to watch is that although the outer diameter of the bush *should* fit in a TO220 hole, tolerance stack up sometimes means that it is a very tight interference fit. Feel the force, kgsshv buider, feel the force. Believe it will go in and it will. They are going in alright, my dremel with a drill rasp saw to that. The interference fit was a bit too tight, no problem chasing the TO-220 mounting holes about ~.002" with a dremel. The extended length shoulder washers* plopped right in the last time around. *Mouser p/n: 532-7721-3PPS Gonna do it again this time, using the ceramic oxide tombstones as Nattonrice suggested. Mouser does not carry the all plastic fqpf80n80c sand. (26 week lead time) So I'll be using the TO-220 sand I have with the exposed metal mounting tab. I've never used future electronics, Mouser is my friend. Edited February 6, 2011 by livewire
livewire Posted February 14, 2011 Report Posted February 14, 2011 Well this really sucks and blows. It seems the Post Office has lost my Mouser repair parts order. It had a tracking number, they say that they delivered it. It sure wasnt delivered to my address unless there is someone in the neighborhood stealing packages out of mailboxes. Am gonna place another duplicate order, this time shipped using another carrier. We'll see. Wait, wait, wait. Just curious. There are at least four other people out there with kgsshv board sets. It would be nice to hear of your progress in building this thing. Seems that I am going nowhere fast, maybe someday I'll hear music from it.
Emooze Posted February 15, 2011 Report Posted February 15, 2011 Did you try calling Mouser? I had one of my orders stolen out of a package and they sent me a replacement at no cost to me. Granted my order was only ~$7 but it's still worth a shot.
livewire Posted February 15, 2011 Report Posted February 15, 2011 No I didnt call them. I guess I could, got nothing more to lose. Mouser does have a disclaimer on their website trying to discourage customers from using the USPS for their shipments due to this type of crap. I wish that they would use "signature confirmation" instead of the "delivery confirmation" option. With the former, they must deliver it to someone and have them sign. With the latter method any mailman can misdeliver it and sign off on it. (what I suspect happened here - my mailman is a demented old puke) UPS or Fedex aint much better, if I'm not home they will leave the parcel on my doorstep in plain view of any dirtbag walking by on the street, ripe for the pickin.
livewire Posted February 28, 2011 Report Posted February 28, 2011 Got the repair parts in from Mouser, so troubleshooting the psu continues. Things still aint right, the negative 450 volt rail is still outputting only 15 volts. The positive rail which was completely dead, now has voltage, but it is off the charts. (at least as far as my 600 volt limited Fluke DMM is concerned.) This much higher than normal voltage is also backfeeding into the filter capacitors. o_O! That's not good! I am not able to read it, so I guess it is time to dust off my old Simpson 260 that is in storage in the garage, which is capable of reading up to 1000 volts. The only (high) voltage that is still normal on the psu board is the 580 volt bias output. At least I didnt blow that up. The 15 volt supply is also working again. What would be nice would be knowing some nominal testpoint voltages so I could test for those. I'm too stupid to figure out what the base/gate voltages should be that are fed in from the rather complex (to me) sub-circuits. (such as the "battery" circuit) Blub, blub, blub. (i'm trying to tread water here!)
livewire Posted March 1, 2011 Report Posted March 1, 2011 Yippee! I got the +450VDC psu rail working again. No more over-voltage issues to deal with. Now with one side good, I can revert to comparitive live testing between the good side and the bad side. Hopefully, I'll get the negative rail back up soon. That is if another parts order to Mouser isnt necessary.
Lil Knight Posted March 1, 2011 Report Posted March 1, 2011 So what's the problem with your positive rail?
livewire Posted March 1, 2011 Report Posted March 1, 2011 (edited) (long version) About a month ago while testing I slipped with the probe and shorted the two pass regulators. (fqpf8n80c) They were toasted along with the 10m90s and 2SC4686A sand in the positive rail. The 24 volt zener popped too. I had replaced them all yesterday and started to test again today. After noting the bar graph on my Fluke shooting past 600 volts and blanking the display, I shut it down. I went back to cold comparitive testing using the resistance scale. It was then noted that one of the devices that I had changed was shorted. (the 10m90s) The new one on the negative rail had an in-circuit reading of ~3K ohms between the gate and the other terminals, the new one on the positive rail was ~28 ohms. So, I guess it was a bad part or that the soldering did a number on it. This time around I bought extra sand. I replaced it a second time and everything is now working fine again on the +450VDC side. Edited March 1, 2011 by livewire
livewire Posted March 1, 2011 Report Posted March 1, 2011 It's back to Mouser again. I think I need another 2SC4686A... I'm ordering a box-full of them as insurance. (the amp boards have a boatload of them too...)
ujamerstand Posted March 1, 2011 Report Posted March 1, 2011 I'll be looking to you for replacements if one or more of my devices blow up. Good Luck.
n3rdling Posted March 1, 2011 Report Posted March 1, 2011 Get this thing working so I can listen to it in San Diego
livewire Posted March 1, 2011 Report Posted March 1, 2011 That's what I am attempting to do. Then it might give you a good reason to go to our nascent meet and make the two hour drive down from LaLaLand.
livewire Posted March 16, 2011 Report Posted March 16, 2011 I'M SOFA KING WE TODD DID. CANT FINGER DIS TING OUT.
mypasswordis Posted March 16, 2011 Report Posted March 16, 2011 What exactly are you having trouble with now? Still the negative rail?
livewire Posted March 16, 2011 Report Posted March 16, 2011 In a word, yes. I've replaced almost everything on the negative side Cross checking against the good +450 volt side is difficult due to the groundplane linking everything when hot. If there were two separate identical 1/2 psu boards instead that were linked like in the schematic, it would be more straightforward for newbie comparison testing. It was working originally, so my goofs created a hole that I must now crawl out of. Knowing some testpoint voltages at the regulators and battery for instance could shed some light on the trouble spot(s). I wanna say "I'm done, stick a fork in me", but i'm not there yet.
mypasswordis Posted March 16, 2011 Report Posted March 16, 2011 Is this the same board that got fried twice? I know you don't want to hear this but if it were me I'd repopulate on a new PCB since it was working before it got fried so that means there shouldn't be any errors in the PCB, pre-fry. And since the positive and negative rails are basically the same, other than deriving the bias from the positive rail, if you can't spot the problem on sight it may take a really long time. If you don't want to go that route, maybe post up some pics?
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