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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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