Kitchen Aid Superba KUDS series, installed 2001, similar/identical to Whirlpool -- live, but no Start and no response to button-press.
The reset sequence of pressing two buttons multiple times did not work, either. Cycled power, no go.
Power off, remove six screws (torx 7 heads) examine circuit board: Saw two 63V/100uf caps, two more 10V caps, all appeared normal. Mutiple color-coded wires to board,
got all disconnected, dismounted board from housing. ESR test showed that 63V caps had failed.
Jamicon 105 C TK series, 8D x 12. Replaced both with equivalent ...
magistertc
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Last Activity: 04-17-2024, 05:19 AM
Joined: 02-11-2006
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Kitchen AId dishwasher unresponsive
Starts04-17-2024Ends04-17-2024LocationKansas USA -
Well, JPJ,
This post will not address your issues directly. (and has nothing to do with caps or electric heat). But....
Virtually every locale requires a permit to build, followed by inspections. Then add a rider to your insurance, not insuring may be a costly error.
Determine locale. Easiest is outdoors, if you have a safe area separated from other buildings. Indoors is doable, with different caveats.
Outdoors, you can generally use a wood stove designed for sauna, or cobble up something according to requirements
Indoors, it will be electrical,... -
Re: First oscilloscope thoughts
Look at the readme -- author has a point about unsuitability of USB, though ver 3 USB is somewhat faster. I used this paralllel port interface to sort out some timing issues in an MCU set up for matrix switching. With all possible services stopped, the only interference was from the PC clock signal, which I had to occasionally work around. I don't know what jitter would be like unless your signal is introducing it.
IMHO a cheap USB logic analyzer is probably wasted.Leave a comment:
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Re: First oscilloscope thoughts
Digital Logic Analyzer - FREE
ElmüSoft is a freeware app that uses a parallel port to manage TTL logic for up to 17 channels. If necessary you can install a cheap parallel port in your computer to suit. Use level shifting to manage non-TTL signals.
I have used this for several projects, 3-4 channels up to about 50MHz on a P4 machine.. It takes some practice and experience to get good results, but certainly worth a try. And you can't beat the price.
Diagrams and explanations here:
[url]https://www.codep...Leave a comment:
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Re: Interesting Failure
Actually, I believe this PS was overloaded, the plastic around the mounting hole looks scorched. Crack in case, path to ground for 300V pulses, metal eroded. Mini-flashover.
I used a mica insulator with the new switcher, runs ok at about 150W, possibly good to 200-250. Not suitable for newer systems with heavy 12V load, it's going to become a bench supply, keeping the load under 150.
Leave a comment:
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Interesting Failure
This Enermax is pretty old ... for P4 systems. Dead when I got it, blows fuses. I tried several times to troubleshoot, no joy, probably in switcher circuit?
So, getting ready to part it out, I removed the mosfet switcher with the heat sink and then FINALLY took it off the heat sink. Surprise!
This thing had passed ok when tested, but that was only with~5V diode test on DMM. Seems like it was overloaded some time in the past, but cleverly kept its condition hidden until now.
TC... -
Re: Samsung 940N No Backlight - BN400121A Analog Board
Nope -- just that this model is probably 10 years old and by now there are not too many in use. The one I worked on went back to the owner so I do not have access to it.Leave a comment:
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Re: Samsung 940N No Backlight - BN400121A Analog Board
@C152Heavy
I'm inclined to agree with you. I did not find those AUK datasheets, which do match the Q301/302 (RA4/RC4) markings. Clearly, a SMD transistor with sufficient mA capacity would work in that circuit. Replacing Q302 with a MOSFET out of my junk box solved my problem, so I stopped searching at that point.
TomLeave a comment:
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Re: Samsung 940N No Backlight - BN400121A Analog Board
My daughter board is marked 'PowerNet PWI1704'
I researched RA4/RC4 a bit, decided they might be MOSFETS (I might be wrong!) and found some possible substitutes:
Q301, RC4, N-chan?: Si2304 or BSS138
Q302, RA4, P-chan?: Si2303 or BSS84
If you have diode test option on your multimeter, you can do a basic mosfet test, negative lead to source, touch positive lead to gate, then switch to drain to check whether it is switched 'on'
Touch finger to source and gate simultaneously,...Leave a comment:
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Re: Samsung 940N No Backlight - BN400121A Analog Board
I fixed a 941BW which was flat dead -- would not respond at all.
You will need to remove the daughter board to replace an SMD component.
First, look at my very rough drawing, marking the test points. Check for +15v at Vcc and signal at ENA. If those are good, check Q302D for voltage. Controller is OZ960SN, check the test point on top foil side near the connection marked 'BT.' If that is good, the problem is further along in the circuit.
In my case I believe that Q302 was not adequate for...Leave a comment:
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Re: Building an ESR meter, some help and someone to check my PCB layout
Oops, post # 18, that R11 should be 3K3 = 3300 ohms = 3.3K ........Leave a comment:
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Re: Building an ESR meter, some help and someone to check my PCB layout
@Garry:
I built this a while back, used with a Simpson model 313 meter which has 100uA input. I increased R11 on the transistor to 3R3 and added 0.1uF cap parallel to R12. Substituted a 5K pot (instead of 25K) in series with the meter. Bought the IC, rest of the parts came from my spares bin. Resolution is good above 100uF and good enough down to 2uF to spot a high-ESR cap.Leave a comment:
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Re: Hp compaq cq60 keyboard and touchpad not working
Had this problem last year, built-in keyboard and touchpad would not work and could not re-install the drivers. BUT it would work with USB keyboard and touchpad. IIRC it was an Acer laptop....
Ran SFC /scannow and dug through the log - found possible corruption error for one obscure file (wdf01000.sys in this case). I got a copy from another machine, had to futz with the permissions to do the replacement, and that took care of it.
/* edit Built-in keyboard would work during boot, just not with windows...Leave a comment:
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Re: LG Flatron L1732TQ -Display "out of range"
Older LCD monitors were often limited to 60Hz refresh rate. Some newer ones will work up to 85Hz, but you might check (maybe with a different monitor) that you are set to 60.Leave a comment:
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Re: Samsung Syncmaster 940BX backlight problem - Need help please.
Hotdig,
Good of you to grab the datasheet - it is not the IC that I expected, however.
Please check the voltage on OLP pin 1. Note that it should start somewhere around 2.2v (per datasheet) and it if drops to ~1.5v the chip shuts down the inverter. That might give you a clue as to where to look next. Keep us posted
MLeave a comment:
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Re: Samsung Syncmaster 940BX backlight problem - Need help please.
hotdig,
See if you can get the ID off the chip on the bottom - 16 lead surface mount. And if you feel skillful enough, try to read the voltages, particularly on pins 6, 7 and 8. I had a Samsung with a bad resistor on the overvoltage ref pin and it took me most of a day to figure it out. Worth pursuing before you do anything drastic.Leave a comment:
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Re: AL1916W: backlight goes deed after 5s
Bookworm,
Check also OVPT, pin 7, of the 16 pin IC on the 'green' solder-side of the board (looks like an OZ---- part, but I cannot read the p/n or ID in the service manual) - that ref voltage should be somewhere around +2.5V. I fixed a monitor where one of the divider resistors had gone open and the voltage on was too low, IC would shut down the inverter when it detected normal operating voltage on pin 6 (Vsens). See post #58 here:
[url]https://www.badcaps.net/forum/showthread.php?t=6930&page=3[/url]Re: AL1916W: backlight...Last edited by magistertc; 10-04-2009, 03:46 AM.Leave a comment:
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Re: Samsung Syncmaster 225BW
Sorry, I did not bookmark the datasheet URL but I did print some of it.
Had to shrink the jpeg a bit to get it attached here.
pinout:
1 + 15 inverter driver outputs
2 - Vdd +5V
3 - timer - RC constant for shutdown when problems detected
4 - dim - usually external voltage 1-2v to set brightness
5 - isen - current sensing on return side of ccfl tubes
6 - vsens - proportional to inverter output
7 - ovpt - overvoltage ref signal, somewhere arount 2.5v (AFAIK)
8 - 9 - no connection...Last edited by magistertc; 09-14-2009, 10:34 AM.Leave a comment:
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Re: Samsung Syncmaster 225BW
I just spent a wonderful afternoon with a Samsung 920BW. Caps ok, power ok, backlight comes on for a second or two and then off - video ok.
On the back of the power/backlight circuit board, I finally was able to read the TINY, TINY p/n on the inverter controller chip. OZ9938. Got a datasheet, comes with reference application circuit. Pin 7 is overvoltage protection, in case a CCFL is dead or not working right. A reference voltage is set there, and when Vsens signal on pin 6 rises above that, the controller shuts off (after about a second)....Leave a comment:
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Cleaning holes in m/b
I have not worked my way through all the tips - but this is one I learned back in the 80's, replacing ICs that were soldered in place. If somebody has already presented it, my apologies.
Unsolder and remove caps using your preferred method - carefully, of course.
Get a few round toothpicks. Take one, dip the end in water, just so it is not totally dry.
It helps to have steady hands and good eye coordination, and occasionally an assistant when handling the iron around critical, sensitive parts.
Use the soldering iron to heat a component...
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