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| Test Equipment Anonymous (TEA) group therapy thread |
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| mnementh:
--- Quote from: mnementh on July 03, 2022, 01:34:23 am ---WELCOME TO 5000! --- Quote from: factory on July 02, 2022, 07:48:19 pm ---From the Agilent 54654N diagrams, that were linked to recently. The monitor cable has three connections for +15V and ground, six total. Three connections for the intensity pot. Last four connections are half bright, full bright, HS (Hsync?) and VS (Vsync?). Interesting the HS goes through a 74393 to provide the probe compensation signal. HS & VS come from the big Jackal custom IC and the half bright, full bright from a PAL IC. Other relevant pages have been cropped, rotated & added below. This forum post suggest the Hsync is 19.72kHz and the Vsync is 60Hz. https://www-elektronik-si.translate.goog/phpBB2/viewtopic.php?t=30373&postdays=0&postorder=asc&start=30&sid=c8ec2c01726d6cc1ee123fe5ebbe8c3d&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp Guess I need to locate those on my 54615B, to try & narrow down where my intermittent horizontal roll problem is, but it's not the same board. David --- End quote --- Okay, I've traced out the 54621D and the VCC, GND are in the same locations, plus Pin 10 dssig_grd is also tied directly to GND. However the BRIGHTNESS pot is not brought out to this header on the 54621D. VSync HSync My guess is that 13/14 are still the sync signals, and they have repurposed 7, 8, 9, 11, 12 for their greyscale scheme. 54645A agrees; trace 1 is the 54621D, trace 2 is the 54600A. However, pin 8 is a different story; all I'm getting from the 54600A is noise. :wtf: Then the light dawns; the pot isn't connected to the monitor PCB, duh. Then it occurs to me the voltages usually present on a brightness pot, so I connect the cable back in the 54600A and probe the pot. Yup... (-58V) sent out pin 9 to the pot. Without knowing how the 54621D does its greyscale, I'm not too sanguine about connecting that (-58V) back to its mainboard. I think this is probably a good point to call it a night. ;) mnem :-BROKE --- End quote --- Stay tuned. >:D mnem *yawwwwwnnnn* "This will probably be at least a 3-coffees move." |
| mnementh:
--- Quote from: Cerebus on July 09, 2022, 12:45:28 am --- --- Quote from: tautech on July 08, 2022, 11:35:59 pm ---... being their biggest focus rather than staying in their lane and sticking to their knitting ... --- End quote --- Would Sir like his metaphors diced, or scrambled? :) (Only Mickey Spillane is allowed to have his metaphors hard boiled.) --- End quote --- "Please Hammer, don't hurt 'em!!!" mnem *fulminating at the mind again* |
| mnementh:
--- Quote from: mnementh on July 09, 2022, 12:00:58 pm --- *yawwwwwnnnn* "This will probably be at least a 3-coffees move." --- End quote --- Allright... maybe slightly more than 3 coffees... The mouse on my workshop PC has developed a hinky left button, resulting in very random double-clicks and dropouts while highlighting. mnem |
| BU508A:
Repair Shimano EC-E6000 Battery Charger A friend of mine brought me the other day a battery charger from Shimano. Failure description: Doesn't work anymore. Opening was easy, just four screws. First thing I've measured was the fuse. Jep. fuse open. Next step: measuring the conductivitiy between the + and GND rail after the rectifier. Jep, 0.02 Ohms. A closer visual inspection revealed two exploded LCS703H. Ordered a bunch of five at Mouser, they'll arrive next week. And here are some pictures: Plastic case, easy to open: Top and bottom view of the PCB: One of the exploded LCS703: Parts overview and detailed view. Interesting, those LCS703H had a separate plastic case on top. An annoying thing was: they've putted some Loctite on the screws. Had to be very careful to get them out. Edit: Forgot to add the details of the parts: - bridge rectifier: D15XB 60 B1362 - 2x LCS703H - fuse: T6.3AH 250V, 5x20mm Anybody an Idea where to get those fancy caps for the fuse with those legs? I've attached the datasheet of the LCS703H below. |
| bd139:
Ooh explodey. Hope it works afterwards. I love how the fuse goes about 200ms after every semiconductor goes pop in SMPS designs. Fuses are literally just fire prevention these days. Edit: trying not to buy that 3478A I don’t need at the moment :-DD |
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