By cutting the trace you have disconnected Q7204B base, Q7204B emitter should have 16vdc (vcc voltage) and its collector voltage would be set by ic7202, I suspect Q7204B collector is going high and that turns on the base of Q7204A, which conducts taking ic7201 pin2 (vsense) low shutting it down. I suspect under normal conditions Q7204A would be turned off so I would check the resistors etc around ic7202 or ic7202 might be bad?
Also make sure your vcc voltage is 16vdc A weak C7114 or C7226 could cause high frequency noise on the vcc line
With the trace cut and pfc working you...
R_J
Badcaps Legend
Last Activity: Yesterday, 04:31 PM
Joined: 06-28-2012
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When you are trying to read the eeprom with a clip, you are supplying vcc voltage to the entire board, cpu memory etc. and the programmer usually cannot supply the current. there is no isolation between the eeprom's vcc pin and all the other ic vcc pins, and the cpu may also be trying to access the eeprom at the same time you are trying to read it. Remove the ic and read it.Leave a comment:
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What I am saying is that trace repair should not cause the board to be dead, you must have done something else, if you remove the wire do you think the board will start to work as before? the wire only replaced the trace it did nothing else. Maybe there are other poor solder connections on the plugs....Leave a comment:
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Looks like it is a MMDT2227Leave a comment:
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Is that fan that you pictured the one that you are trying to replace? or are you just trying to add a fan to the compressor? just wire the 240v fan across the compressor motor so the fan runs when the compressor runs...Last edited by R_J; 11-26-2025, 06:54 PM.Leave a comment:
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So now you have a 240v fan?...Leave a comment:
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Without any pictures of your repair job, it's hard to comment. the trace connection to the relay was not making connection, if it didn't get soldered properly the fault would be the same, the heat would not have hurt the relay. check your solder connections, check that you connected everything correctly...Leave a comment:
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one workaround would be to get a small line transformer 240vac ~ 120vac it would not need to supply much current just to run a fan
I see the original fan is not cheap....Last edited by R_J; 11-25-2025, 04:46 PM.Leave a comment:
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The fan motor is also used as a stepdown transformer to provide 21vac for the stirrer and drive motors, the yellow and blue wires likely connect to those motors so 120vac would connect across pins 1 and 3, and between 3 and 2 you will have 21vac. the direction of rotation cannot be changed by reversing the wires.Leave a comment:
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If this image is helpful give me one billion dollars...
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How long does it hold its memory, how long is not very long? if its less than a couple weeks then try replacing C376Leave a comment:
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Contact oemsecrets, i'm sure they can helpLeave a comment:
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You can try replacing C11, but I suspect it is just the fluorescent display is too old and loosing emissionLeave a comment:
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Look at the last picture
25V, but 35V would be fine as well
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Richtek RT8231AGQW There could be a short in whatever it supplies ie: shorted mlcc (smd capacitor)Last edited by R_J; 11-12-2025, 06:15 PM.Leave a comment:
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I'm sure whatever you replaced it with is fine, you likely have other problems than just this cap, for a cap to blow like this is usually reversed polarity or too high a voltage or it internally shorted....Last edited by R_J; 11-12-2025, 06:07 PM.Leave a comment:
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470µf / 25VoltLeave a comment:
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Texas Instruments TPS62400DRCTLeave a comment:
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sometimes there is other information under the part number that might hint as to who made it, I saw a picture of a similar board, but it used a totally different ic in that area.Leave a comment:
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