BK Precision 885 886 lcr Identify theses masked / buffed ic's ...

[coromonadalix]

I want to repair an "Bk precision 886 lcr meter"  around year 2000-2001 handheld lcr, did not receive full permission to show the full schematic here, (waiting for an answer) but allowed to do some search.

All majors ic's are buffered, no saliva work, and believe me i searched tons of info's/photos/markings on the web

EDIT : Just found out pictures (google will show you theses on a model search) and a manual / schematics and calibration,  possibly / surely converted in jpegs pages

Basically i need to id the chips inside

More photos to come ...  maybe not ?

Identified so far  (Warning : errors may be still possible in the parts identification)

u101  =  Holtek   HT1621b               RAM Mapping 32x4 LCD Controller for I/O MCU
u102  =  HSDL-3610                         IRDA  emitter / receiver
u106  =  HSDL-7001                         IR 3/16 Encode/Decode IC
u107  =  could be an AT89C52         CMOS 8-bit microcomputer                                                                      thks  @fzabkar
u108  =  SN54LS373 / SN74LS373   Octal latch                                                                                               thks  @fzabkar
u109  =  AM39SF010 / AM29C010 /  AM29F010              1 Megabit (131,072 x 8-Bit) CMOS                            thks @shakalnokturn
u110  =  MCM6264C                                                       8K x 8 Bit Fast Static RAM                                          thks  @fzabkar
u111  =  LT1302                                                                                                                                               thks  @fzabkar
u112  =  LM393
u113 =  AIC1117cy    800ma Low Dropout Positive Adjustable Regulator      sot-223 case

u201  =  TMS320C203 or TM320LC203 (100 pins) Digital signal processor                                                      thks  @fzabkar                                     
u202  =  82C55                plcc44 pins                                                                                   
u203  =  74ls138
u204  =  similar to IDT71016S (CMOS Static RAM 1 Meg, 64K x 16-Bit) but with shuffled address bits             thks  @fzabkar
u205  =  AT27C1024 /  AT29C1024
u208  = Maxim MX7524, AD AD7524, TI TLC7524                                                                                              thks @Macboy
u212  =  AD9832    DDS                                                                                                                                     thks  @fzabkar
u215  =  TPS76501D                                                                                                                                          thks @Macboy

u315 = 4051 8:1 analog multiplexer                                                                                                                  thks @turbotom

[coromonadalix]

Still has some intermittant supply problems it seems, maybe cold solders ?

Sorry  wasn't clear enough

[fzabkar]

The pinout of U205 (64K x 16 OTPROM) is similar to an Atmel AT27C4096 (pin 43 differs):

http://ww1.microchip.com/downloads/en/DeviceDoc/doc0311.pdf

Edit: http://ww1.microchip.com/downloads/en/DeviceDoc/doc0019.pdf (AT27C1024, 1Mbit, 64K x 16, pin 43 differs)

U204 is similar to IDT71016S (CMOS Static RAM 1 Meg, 64K x 16-Bit) but with shuffled address bits:
https://www.idt.com/document/dst/71016-data-sheet

I guess it's obvious to all, but U215 is a power supply supervisor IC in an SO-8 package. The FB pin appears to sense the target voltage.

The potential divider would suggest that the FB reference voltage is 1.24V.

165K / (165K + 499K) x 5V = 1.24V

FWIW, if the FB pin were set to trigger when it drops below an internal reference voltage of 1.2V, then the output voltage would need to drop to 4.83V.

(165K + 499K) / 165K x 1.2V = 4.83V

I haven't checked all the pins, but U201 could be a TMS320C209:

http://www.ti.com/lit/ds/symlink/tms320c203.pdf

[coromonadalix]

@joeqsmith   

Nothing signed,  but discussed in email only .....  they told me no parts available ... and please dont show the full schematic, keep it a mystery untill i receive the permission to tell the model ??

The dds chip is already an information giver ...

I asked:  do you have an crossover part list,  response was nada, niet ?

[fzabkar]

@fzabkar   u204    must be in the same family,  the port "A"  pins differs ...  thks  its a good pointer.
                  u 205   too

"Port A" is not a port, AISI. Those are the address bits. In any case, it doesn't matter if you shuffle the address bits. It only matters when you try to make sense of the dump.

[coppercone2]

we had a similar case to this back in the 80's, people started going missing...

[coromonadalix]

@fzabkar   u204    must be in the same family,  the port "A"  pins differs ...  thks  its a good pointer.
                  u 205   too

"Port A" is not a port, AISI. Those are the address bits. In any case, it doesn't matter if you shuffle the address bits. It only matters when you try to make sense of the dump.

Yes  my bad, adress bit     thks


thks  @fzabkar           very good detective work   


EDIT u215 could be in the

TPS7101Q, TPS7133Q, TPS7148Q, TPS7150Q
TPS7101Y, TPS7133Y, TPS7148Y, TPS7150Y

family

[fzabkar]

U108 is an octal latch -- eg 74373, 74374

https://www.onsemi.com/pub/Collateral/SN74LS373-D.PDF

U110 looks like an 8K x 8 static RAM eg 6264.

http://users.ece.utexas.edu/~valvano/Datasheets/MCM6264.pdf

U109 = 128K x 8 SRAM, very similar to V62C5181024, but slight pinout differences.

http://pdf.datasheetcatalog.com/datasheet/mosel/V62C5181024.pdf

U111 appears to be regulating a 5V supply. If so, then the voltage on its FB pin would be ...

56.2K / (56.2K + 169K) x 5V = 1.248

So we need to look for a PWM regulator with an internal 1.25V reference voltage.

U111 looks similar to the LT1305, but it is NOT compatible (it differs in pins 2 and 5, but FB = 1.24V).

https://www.analog.com/media/en/technical-documentation/data-sheets/lt1305.pdf

Edit: U111 could be an LT1302.

https://www.analog.com/media/en/technical-documentation/data-sheets/lt1302.pdf

U113 appears to be a standard 3-terminal regulator. If the voltage differential between its Vout and Adj pins is 1.25V, then it is configured as a 154mA current source, probably to trickle charge the battery.

1.25 Volts / 8.1 Ohms = 154mA

U107 looks very similar to several ICs like this one, but the pin count is different:

https://doc.lagout.org/electronics/doc/ic_various/at89c52.pdf

[fzabkar]

EDIT u215 could be in the

TPS7101Q, TPS7133Q, TPS7148Q, TPS7150Q
TPS7101Y, TPS7133Y, TPS7148Y, TPS7150Y

family

http://www.ti.com/lit/ds/symlink/tps71.pdf

The pinout is wrong, although the pin names are a match, but even so, the device in the circuit diagram appears to have the same input and output voltage (?), so I'm having a hard time believing that it could be a linear regulator of any kind. I was sure that the device had to be a supervisor IC, but now I'm starting to feel stupid.

[shakalnokturn]

For U109 maybe more like a 128k x8 flash "ROM" the "LCC32" points more that way. Code for the DSP?

39SF010
29C010
29F010

[coromonadalix]

EDIT u215 could be in the

TPS7101Q, TPS7133Q, TPS7148Q, TPS7150Q
TPS7101Y, TPS7133Y, TPS7148Y, TPS7150Y

family

http://www.ti.com/lit/ds/symlink/tps71.pdf

The pinout is wrong, although the pin names are a match, but even so, the device in the circuit diagram appears to have the same input and output voltage (?), so I'm having a hard time believing that it could be a linear regulator of any kind. I was sure that the device had to be a supervisor IC, but now I'm starting to feel stupid.

Dont say that,   i just searched app notes for the TMS320 DSP chip,  and theses numbers appeared, they do seem similar, but your first assumtion may be good.

[/quote]
U113 appears to be a standard 3-terminal regulator. If the voltage differential between its Vout and Adj pins is 1.25V, then it is configured as a 154mA current source, probably to trickle charge the battery.

    1.25 Volts / 8.1 Ohms = 154mA[/quote]

A warning has been issued with the switch (s103 dc-dc converter section), if its not in the right position, an ordinary battery can or could ne wrongly chanrged and could burst ?

[fzabkar]

For U109 maybe more like a 128k x8 flash "ROM" the "LCC32" points more that way. Code for the DSP?

39SF010
29C010
29F010

Doh! You're right.

http://noel.feld.cvut.cz/hw/amd/16736f1.pdf

[CJay]

As FZabkar has stated, U107 is some variant of the venerable 80c5x microcontroller.

[coromonadalix]

u113 =  AIC1117cy    800ma Low Dropout Positive Adjustable Regulator      sot-223 case

[coromonadalix]

Managed to get this from a web site with a link to an other one for the images ...


BK Precision 885  886      Originally known as Motech MT 4080A  (100khz version)

And i got an  Part list with calibration procedures AND the schematics ??  seems the same has the one provided to me   year 2001 ...

BUT they are jpegs images and i removed the website markers in the lower right corners images

They did not had any confidential warnings, but they may have been edited prior me


Theses images show on some google image search ...  just checked

My 886 is in the same shape for the buffered chips,  all major ones,  even u101  the holtek display driver.

[TurboTom]

U315 = 4051 8:1 analog multiplexer

[coromonadalix]

thks

that leaves the 2 final ones

u208    supervisor ic or an voltage regulator ..... something  loll
u215    its a dac for sure

[TurboTom]

U215 = TLC7524 multiplying DAC

... I mean U208 of course ...

[CJay]

U208, MAX7253

[macboy]

U215 is a an LDO with enable input and power-good output.
Example is TPS76501D which matches both function and pinout exactly (except for unknown design current or power dissipation).

[macboy]

U208, MAX7253

I think you mean the Maxim MX7523 (note: MX not MAX). This is equivalent to Analog Devices AD7523. But that can't be it, because both pins 12 and 13 are connected, but are N/C on those devices. The 7524 is a match (Pin 13 is /WR and pin 12 is /CS). So it could be Maxim MX7524, AD AD7524, TI TLC7524.

[coromonadalix]

And now the calibration procedures ( thoses aren't restricted )  for the BK Precision 885 886  lcr meter  ... attached photos

Haven't received a response to show the schematics ....


Thks to all the detective(s) work, hope it help   for future calibrations and or repairs if needed

Will upload these image to K04BB


As i see it the 10khz model (885)  and the 100khz (886)   share the same identical design (i dont know for the 100khz info in the 885 lcd ??), must be a firmware restriction,  dont want to damage mine trying to make a firmware dump ... but would have been nice to try a 885 ---> to 886 conversion ??

[coromonadalix]

Everything upped to K04BB   in the Recent uploads

Contains the schematics / calibration  (from a chineese link) / part numbers  and added the first thread part numbers equivalents, no firmware.
   

BK Precision 885 - 886 BK Precision 885 886 lcr meter aka Motech 4080 Service Manual-886 calib31072019.zip      ------  11 megs


thks to all who helped me here.


I think mine is repaired, redone a few solders in the psu section, seems to hold.

[lzqing]

Thank you Coromonadalix!
Nice shareing for the k04bb.
I just want share communication process for serial ports of a working machine here .
By the way, There are a lot of cases seem  firmware locked or damage the flash , anybody have idea for fixed this issue ?

[MarkL]

I wanted to share another version of the schematic for the 885/886, below.

I didn't do a detailed comparison to the schematics that have already been posted to this thread and uploaded to KO4BB, but it appears to be a more recent version.

One thing I did notice is a little section labeled "USB PORT".  I have an 886 and it's not spec'd to have a USB port, but it's there!  It's well hidden under a bar-code sticker, which is on top of a thin gray piece of stick-on plastic that exactly matches the case color, which is on top of a small piece of stick-on rubber.  See photo.

Plugging in the USB, from linux dmesg:

  usb 1-4.1: new full speed USB device number 13 using ehci_hcd
  usb 1-4.1: New USB device found, idVendor=10c4, idProduct=ea60
  usb 1-4.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
  usb 1-4.1: Product: CP2102 USB to UART Bridge Controller
  usb 1-4.1: Manufacturer: Silicon Labs
  usb 1-4.1: SerialNumber: 4080IJ1140
  usb 1-4.1: configuration #1 chosen from 1 choice
  USB Serial support registered for cp210x
  cp210x 1-4.1:1.0: cp210x converter detected
  usb 1-4.1: reset full speed USB device number 13 using ehci_hcd
  usb 1-4.1: cp210x converter now attached to ttyUSB0
  usbcore: registered new interface driver cp210x
  cp210x: v0.09:Silicon Labs CP210x RS232 serial adaptor driver


The USB port works (9600/8/N).  It appears to operate the same as their benchtop version of this meter, the 889B.  You can find the commands and data formats documented in the 889B manual.

I never really thought much about the "Remote" label on the front of the meter.  Maybe there's a problem with USB and they withdrew support for it, or maybe they didn't want it to encroach on 889B sales.  Maybe it's not on all versions of the 886.