Electronics > Repair
Fluke 289 not quite sorted.
ElecSeb:
Update from my side:
This afternoon I have finished my analysis from all SOT23 elements. All seem to be fine.
However last time I was playing with it I massively f&ckedup and created a shortage on U20. This now results in having a short between L1 and ground |O
Initially the unit did not work and I broke L1 coil, burned 2 capacitors and removed the super-cap. Also removed burned C27 and C36 (hot air destroyed them)
The issue with my unit is, that when I turn it on, I see a green led for lets say 2 seconds, no screen and no power (unit is really off). Therefore I have checked all SOT23 elements.
I have looked-up up almost all data-sheets to see which IC's are used and next is to figure out why some voltage lines are not comparable with a post earlier in this threat.
Luckily I recently purchased a toneohm 850. 1 problem, I never ever used such a device, so I need to figure out how to trace to the broken component.
I already removed CR9, C79 and C67 (randomly -> goose-chase). But I need to do this more structured -> Toneohm.
I have some questions for here on the board already:
1. What are these components (ideally with link to a data-sheet):
Q12, Q13 -> Code 337 -> FDN337N -> N-Channel Enhanced Mosfet + body diode -> Cannot find any data-sheet
Q20, Q21, Q43 -> Code 338 -> NDS338N -> P-Channel Enhanced Mosfet + body diode -> Cannot find any data-sheet
U11 -> Code S08H -> No Idea (AND port????)
2. What is the difference between VR05 and U04 (why is one name with a "U" and the other "VR"):
VR05 ->Code 8H -> MMBZ5233BLT1G -> Zener Voltage Regulators 225 mW SOT−23 Surface Mount
U04 -> Code R1E -> LM4041 -> LM4041-N-xx Precision Micropower Shunt Voltage Reference
3. Is this part a correct replacement for the white capacitors (high precision) -> C27 and C36
Code 223 KZS -> Kemet SMC F125PP223J100
(Original part is in PL housing, but that seems not for sale, however size is then upgraded to PP, SMC series, 223 matches. However KZ is still unknown in code name) -> Any help would be highly appreciated!
@Nixxon:
If your unit is not doing anything anymore, check if U17 is actually giving juice (even when powered off.
U17 = Code PCYI -> TPS770 -> Power 5V ULTRALOW-POWER 50-mA LOW-DROPOUT LINEAR REGULATORS
Tomorrow I will try to find my shortage with my toneohm and once fixed I will dig into this unit a little further.
ElecSeb:
--- Quote from: ElecSeb on October 23, 2018, 04:49:10 pm ---3. Is this part a correct replacement for the white capacitors (high precision) -> C27 and C36
Code 223 KZS -> Kemet SMC F125PP223J100
(Original part is in PL housing, but that seems not for sale, however size is then upgraded to PP, SMC series, 223 matches. However KZ is still unknown in code name) -> Any help would be highly appreciated!
--- End quote ---
Update from Kemet concerning KZS:
Please find below the explanation about the marking for our SMC series:
* 223 is the tolerance code for 0.022uF
* K is the capacitance tolerance code – +/-10%, but as per our catalog we not manufacture only +/-5%, +/-2.5%, +/-2%,
* Z is the code for the voltage means 50VDC
* S stands for SMC
I suppose that the correct PN would be SMC5.7223(1)50J33(2)
Where:
* 1=J (5% -> which is the only one on Farnell)
* 2=Just packaging -> not important for ordering
SMC5.7223J50J33
ElecSeb:
@Nixxon any progress?
nixxon:
--- Quote from: ElecSeb on October 27, 2018, 06:51:37 am ---@Nixxon any progress?
--- End quote ---
Not yet. I am figuring out how stuff works by studying the Fluke 27 Service Manual. That manual includes schematic diagrams as well.
I am also studying how graphical LCDs work, possibly gaining useful knowledge by reading links like:
https://www.microcontroller-project.com/128x64-graphical-lcd.html this one has a 20-pin connector as does the 287/289 320X240 pixel LCD display. I wonder how similar the pinout is.
And why do some graphical LCD's, like the Nokia 84x84 pixel displays, only need 8 pin connectors to work? I will have to read more about this stuff. This could be a start: https://learn.sparkfun.com/tutorials/graphic-lcd-hookup-guide/all
It looks like the LCD flat flex connector traces lead go to the area close to the PCB flip side MC9328MXS chip that includes an LCD controller. I guess I have to study the pinout and do some measurements.
https://www.nxp.com/docs/en/data-sheet/MC9328MXS.pdf
The i.MX Family of applications processors provides a
leap in performance with an ARM9™ microprocessor
core and highly integrated system functions. The i.MX
family specifically addresses the requirements of the
personal, portable product market by providing
intelligent integrated peripherals, an advanced processor
core, and power management capabilities.
The MC9328MXS (i.MXS) processor features the
advanced and power-efficient ARM920T™ core that
operates at speeds up to 100 MHz. Integrated modules,
which include a USB device and an LCD controller,
support a suite of peripherals to enhance portable
products. It is packaged in a 225-contact MAPBGA
package
ElecSeb:
Since I am not that far with my unit I cannot do this (yet).
But why not using your (scope) and test the signals from the connector and sees what comes up?
Furthermore, some posts earlier you mentioned that your device did not power on anymore. Got it fixed?
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