- HP54825A Infinium scope - 1 Update
- Odd wiring in tube ampmschematics - 8 Updates
- Fine pitch trace repair - 7 Updates
| Fox's Mercantile <jdangus@att.net>: Dec 08 09:33AM -0600 The motherboard in the 54825 died, so I bought a 54845A as a replacement. I'd forgotten what a cluster fuck it was dealing with Windows 98. After a bit of the usual flailing around, I upgraded to Windows 98 Second Edition and upgraded the USB drivers, nice, I can mount an external USB hard drive now. I also installed the drivers for an HP LaserJet 1200 printer so I can click the print button on the screen. Next trick is to use this: <https://www.ebay.com/itm/271563447023> to mount the 8 Gig SSD in a Dell PC chassis so I can load Windows XP on it, then do the HP Infiniium XP upgrade. <https://docplayer.net/6691001-Infiniium-upgrade-and-recovery-guide.html> Yes, I'm having too much fun with this. Here's a fun YouTube video of a guy working on a 54835A on the workbench. His has Windows 95 as the operating system. <https://www.youtube.com/watch?v=GbKfZ4WWt4k> -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Dec 07 09:15AM -0800 On Friday, December 7, 2018 at 8:47:44 AM UTC-5, Look165 wrote: > The neutral is easy to check ; around 5-10VAC betweent neutral and > ground (a water pipe for instance or a heater in case of collective > heating). If you are seeing an actual 5 - 10 VAC on the meter between neutral and ground in a household system, and the wiring is otherwise to-code (US NEC), something is wrong. Peter Wieck Melrose Park, PA |
| Fox's Mercantile <jdangus@att.net>: Dec 07 11:48AM -0600 > If you are seeing an actual 5 - 10 VAC on the meter between > neutral and ground in a household system, and the wiring is > otherwise to-code (US NEC), something is wrong. Probably under sized wiring, or a bad connection somewhere along the neutral line. A couple of volts is normal due to the normal voltage drop in a conductor. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Dec 07 10:13AM -0800 On Friday, December 7, 2018 at 12:49:02 PM UTC-5, Fox's Mercantile wrote: > along the neutral line. > A couple of volts is normal due to the normal voltage drop in > a conductor. Maybe so. But that is enough to play havoc with such unimportant items as pacemakers, not to mention what it might do to audio and video equipment. Peter Wieck Melrose Park, PA |
| tabbypurr@gmail.com: Dec 07 11:49AM -0800 > Maybe so. But that is enough to play havoc with such unimportant items as pacemakers, not to mention what it might do to audio and video equipment. > Peter Wieck > Melrose Park, PA how would a couple of volts mains drop have an effect on pacemakers? NT |
| jurb6006@gmail.com: Dec 07 07:53PM -0800 >"If you are seeing an actual 5 - 10 VAC on the meter between neutral and ground in a household system, and the wiring is otherwise to-code (US NEC), something is wrong. " Not true. If one side is loaded heavily that's what happens. One house, window AC units, for example had 25 volts on the neutral because all the A/C units were on one side of the line. In that house it was because the job wasn't planned right. It was code but a shit job. And nothing wrong. This can also happen in some older houses when the main neutral coming in is a smaller gauge than the hots. Even if not. If you put too much load on one side it happens. Then if you blow the neutral fuse, which should not be there logically, it can throw 240 volts into everything on the lightly loaded side. Many houses around here are older. They did not anticipate all the load we have these days. I have had to change the lead in from the meter more than once, otherwise I would have had to put in like a 50 amp main or the job wouldn't be code. I got them ready for the service upgrade to 100 amps. Actually 100 amps is not all that much these days. Not enough if you have a hot tub/jacuzzi or an electric furnace. If you have both, double it to 200 amps. (then they will probably put in a peak load meter to pick your pocket more effectively) |
| jurb6006@gmail.com: Dec 07 07:57PM -0800 >"how would a couple of volts mains drop have an effect on pacemakers? " It won't. It also should not affect any audio or other equipment that is designed right. The only POSSIBLE problem might be turntable hum but even then... |
| tabbypurr@gmail.com: Dec 07 10:31PM -0800 > >"how would a couple of volts mains drop have an effect on pacemakers? " > It won't. It also should not affect any audio or other equipment that is designed right. The only POSSIBLE problem might be turntable hum but even then... All domestic mains current loads are balanced, ie live & neutral carry the same & opposite current, resulting in nearly zero magnetic field. Pacemakers, like any life-critical medical equipment, are designed & tested to meet harsh real-world conditions & keep going. NT |
| Phil Allison <pallison49@gmail.com>: Dec 08 02:49AM -0800 Ralph Mowery wrote: > Several of us were discussing this the other day, but none of us knew > for sure which should come first, switch or fuse in the 3 wire 120 vac > equipment. ** I would opt for switch first, then fuse. This is for the benefit of silly owners who like to swap back panel AC fuses while the item is plugged in - relying on the switch to isolate both ends contacts on the fuse holder. Something that needs to be checked, cos only some fuse holders do this. |
| Look165 <look165@numericable.fr>: Dec 08 12:53AM +0100 Just putting side by side a Scotch for masking. Remove the adhesive immediately before the conductive ink dries. And then repeat with the next track. (Wait at least 1 day). John-Del a écrit : |
| John-Del <ohger1s@gmail.com>: Dec 07 04:07PM -0800 On Friday, December 7, 2018 at 6:53:17 PM UTC-5, Look165 wrote: > Just putting side by side a Scotch for masking. > Remove the adhesive immediately before the conductive ink dries. > And then repeat with the next track. (Wait at least 1 day). Why make things so difficult??? Even dried, there's an even chance the tape will lift the conductive solution, and that stuff doesn't flow out very evenly so even if it's made to be electrically connected, it will look like crap at that fine a pitch. That board can be repaired in 5 minutes or less using fine stranded wire, flux, and flux cleaner - and it will last a lifetime. |
| Jeff Liebermann <jeffl@cruzio.com>: Dec 07 06:56PM -0800 >traces running between the processor and VRAM. Result is corrupted >display output/won't switch into high-resolution modes. The ram is BGA >and the GPU likewise and Common problem with motherboards and steel computer cases with sharp edges. >under a small heat-sink so hard to test >continuity, plus the trace width is very small, looks like perhaps 4 mil: Ummm... 4mil (0.004in) is roughly #38 AWG solid wire. <https://www.calmont.com/wp-content/uploads/calmont-eng-wire-gauge.pdf> Looking further down the chart, you should be able to find stranded wire using something in 2 or 3 mil range. ><https://www.dropbox.com/s/ig9h3vjze5omlie/2018-12-3%2018-11-20.jpg?dl=0> Nicely gouged. >Any suggestions for mending a break on a trace like this? Yep. Dave Platt has the right idea. I'll add a few details. Find some thin plated wire and tin it. Sometimes, I get fancy and flatten the round wire but that's not really necessary. Carefully scrape of the solder mask from over the PCB traces and tin those. Liquid flux helps. Solder one end of the wire, lay the remaining wire across the gap, solder the other end, and CAREFULLY cut off the excess wire. Don't use a knife as you're likely to also cut the PCB trace. Clean off the flux with alcohol, let dry, and test with an ohmmeter. Then, test the PCB. If everything looks good, cover with a little Krylon or other acrylic paint. If you're not sure about the fix, then use some wax, which is easily removable. As Ralph Mowery mentioned, a microscope is very helpful. I use this in the office: <http://www.learnbydestroying.com/jeffl/pics/microscopes/Olympus%20SZ30/slides/SZ30-01.html> and this at home: <http://www.learnbydestroying.com/jeffl/pics/microscopes/Bausch%20and%20Lomb/index.html> I have 6 microscopes, not including parts scopes. Only 3 are suitable for soldering and PCB inspection. I also have a CMOS camera that fits in place of one eyepiece and which can be used for photos and display on an LCD monitor. Notice the use of a microscope, flux, and tinning. However, I disagree with the use of an Xacto knife to cut the wire. QUICK CIRCUIT TRACE REPAIR <https://www.youtube.com/watch?v=a5A61fIu0kk> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| stratus46@yahoo.com: Dec 07 08:55PM -0800 On Friday, December 7, 2018 at 6:56:20 PM UTC-8, Jeff Liebermann wrote: > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060 http://802.11junk.com > Skype: JeffLiebermann AE6KS 831-336-2558 I forgot about the microscope aspect. I'm crosseyed and never learned to see in 3D so stereo scopes have no special value to me. They got me one of these at work. https://www.amazon.com/Opti-Tekscope-Digital-Microscope-Definition-1600x1200/dp/B00PEZ3GMK/ref=as_li_ss_tl?tag=shopperz_origin1-20&ascsubtag=656806266-2-1004874824.1544244057&SubscriptionId=AKIAJO7E5OLQ67NVPFZA I liked it enough that I bought one for home. Looking into the UV window of a 256K EPROM I found the Fujitsu name on the silicon and found that good enough for me. Got mine on eBay several years ago for $45 out the door. Hard to beat that value. G² |
| Jeff Liebermann <jeffl@cruzio.com>: Dec 07 10:04PM -0800 >of a 256K EPROM I found the Fujitsu name on the silicon and found that >good enough for me. Got mine on eBay several years ago for $45 out the door. >Hard to beat that value. Nice for high power close up work, but not suitable for soldering and touch up work. The problem is the objective working distance, which is quite small for your microscope. It's difficult to squeeze a probe or tool between the PCB and the objective lens. Using a smoke belching soldering pencil with such an arrangement will coat the lens with flux. Here's my version of your microscope: <http://www.learnbydestroying.com/jeffl/pics/white-plastic-rot/slides/microscope-setup.html> No room for the PCB or soldering pencil, with a working distance of perhaps 1-4 mm. Meanwhile, my Olympus SZ-3060 biological microscope: <http://www.learnbydestroying.com/jeffl/pics/microscopes/Olympus%20SZ30/slides/SZ30-01.html> has a working distance of 110mm and can be stretched to 400 mm with a 0.25x auxiliary objective lens. See Pg 6 below: http://www.alanwood.net/downloads/olympus-sz30-sz40-sz60-sz11-brochure.pdf Plenty of room for the PCB, tools, soldering pencil. Sorry about the cross eyed problem. Binocular vision (3D) makes working under a microscope much easier. However, I don't know how long that will last for me. I seem to have progressive astigmatism, which is currently causing double vision in both eyes. I forgot to mumble something about lighting. Under a microscope, shadows are a problem. So, a ring light is required. Cheap enough on eBay: <https://www.ebay.com/itm/60-LED-Adjustable-Ring-Light-illuminator-Lamp-For-STEREO-ZOOM-Microscope-US-Ship/271435251906> As for cost, none of my microscopes cost me more than $100. However, all were in need to cleaning, lubrication, alignment, and were missing parts. I've probably spent as much on missing eyepieces, objective lenses, and camera adapters as I have on the microscopes. The real killer was buying the proper Nye NyoGel microscope lube. <https://www.ebay.com/itm/Microscope-Lubricant-Kit-Nye-Rheolube-362HB-NyoGel-767A-NyoGel-795A/292627939054> Oddly, the basic repair tools were quite cheap on eBay. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| bitrex <user@example.net>: Dec 08 01:20AM -0500 On 12/07/2018 09:56 PM, Jeff Liebermann wrote: > disagree with the use of an Xacto knife to cut the wire. > QUICK CIRCUIT TRACE REPAIR > <https://www.youtube.com/watch?v=a5A61fIu0kk> Thanks, I managed to pull it off by scraping away the mask, then lot of flux, tinning, and tiny strand of wire method. Patched up the third trace in from the bottom and video card boots into Windows now and checks out OK, runs shader tests etc. as it should. At age 40 I still test about 20/20 in my right eye, the left was that way too at one time but worse now, but was able to nail the positioning with tweezers and a fine tipped iron freehand, pirate-style this time. I should probably invest in a good microscope, never needed corrective glasses so far in life but check back at 45. |
| stratus46@yahoo.com: Dec 08 01:37AM -0800 The USB scope is used mainly for verifying the solder connections after 'completion'. I use one of these while working. https://www.net32.com/ec/optivisor-magnifier-25x-glass-lenses-fully-adjustable-d-120811?gclid=EAIaIQobChMIktH9o_GP3wIVjwOGCh0DwAAKEAAYAiAAEgKnNPD_BwE The scope has a ring of 8 LEDs around the lens, variable intensity and the focus/zoom can go to infinity. At around 1 cm, 12pt text will fill the screen and is more than sufficient for my use. I use Nye 363 in place of Sony SGL. Great for plastic on plastic or metal. Nye 368AX1 is a heavy grease I use along with NyeOil II. As far as the 3D thing goes, it was a birth problem so I don't know what I'm missing. I was told it's not something to fret over. There were guys flying 747s with my problem. The sad one was when I was working on on an HD telecine design. The customer modified the machine to accept 70mm film and had a 3D transfer that used left and right circular polarization for viewing. I kept telling him I cannot see 3D With binocular vision. Both images were outstanding individually. I CAN see 3D holograms. G² |
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