EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: ahebert on January 28, 2023, 06:20:55 am
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I have a BK Precision 9130 that I hooked up backwards to a battery :palm: and now I a want to replace the burnt parts, but I'm having trouble identifying one resistor value on the main analog board. Labeled #3 in the picture below, does anyone know the correct value?
(https://www.eevblog.com/forum/repair/bk-precision-9130-triple-power-supply-resistor-values-for-repair/?action=dlattach;attach=1701649;image)
In another post (https://www.eevblog.com/forum/repair/bk-precision-9130-triple-power-supply-(identify-component)/msg3750955/#msg3750955 (https://www.eevblog.com/forum/repair/bk-precision-9130-triple-power-supply-(identify-component)/msg3750955/#msg3750955)), @jchw4 posted the following picture of the same board from the top view, but I cannot read the resistor colors from that view.
(https://www.eevblog.com/forum/repair/bk-precision-9130-triple-power-supply-resistor-values-for-repair/?action=dlattach;attach=1701643;image)
Does anyone have a schematic?
Or photo of a resistor where the color codes can be seen?
Or other suggestions?
Any help is much appreciated.
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Sorry for missing your post, I was away from the forum for a few days ;)
I don't have specific photos of these resistors, but I attached a few that you could use as a reference. I was focusing on the MOSFETs and rectifiers, so resistors are a bit blurry.
Let me know if you need more. I stuill have it, but disassembly was a bit painful as I remember :-\
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BTW, could you take a photo of the main IC like I did here: https://www.eevblog.com/forum/repair/bk-precision-9130-triple-power-supply-(identify-component)/msg3745804/#msg3745804 (https://www.eevblog.com/forum/repair/bk-precision-9130-triple-power-supply-(identify-component)/msg3745804/#msg3745804) ?
It would be useful to get more photos and finally identify it :)
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Awesome! Thank you so much! Looks like my resistor #3 is 1-ohm, based on your picture. Now I can order the parts and try the repair.
I'll take a pic of the main IC from my unit and post it later tonight.
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I managed to get a clear shot of the IC, and this one isn't obscured as thoroughly. See attached.
Looks to be an SST89E516RD2 https://ww1.microchip.com/downloads/en/DeviceDoc/25093B.pdf (https://ww1.microchip.com/downloads/en/DeviceDoc/25093B.pdf).
The markings on the bottom-left of your IC photo look distinctly different than this chip. I suspect they are different parts, but since this is an 8051-compatible MCU, I'm guessing that there are a bunch of interchangeable models from different manufacturers.
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Awesome! Thank you so much! Looks like my resistor #3 is 1-ohm, based on your picture. Now I can order the parts and try the repair.
"Brown" "Grey" "Black" "Black" "Brown" - seems more like 180 Ohm to me. :-//
You are probably right, it looks more like "Silver"
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I managed to get a clear shot of the IC, and this one isn't obscured as thoroughly. See attached.
Looks to be an SST89E516RD2 https://ww1.microchip.com/downloads/en/DeviceDoc/25093B.pdf (https://ww1.microchip.com/downloads/en/DeviceDoc/25093B.pdf).
The markings on the bottom-left of your IC photo look distinctly different than this chip. I suspect they are different parts, but since this is an 8051-compatible MCU, I'm guessing that there are a bunch of interchangeable models from different manufacturers.
Thank you very mich! This is interesting.