Micronta 22-167 help?

[subdude17349]

Folks, I posted on an old thread in test equipment, but maybe I'll have better luck here in repair. I have an old Micronta 22-167 that has burned out a resistor. I'm hoping someone may have one of these meters laying around and would be willing to look and see what value R21 is.

Thanks!

Jim

[drussell]

According to the parts list, it is a 4.99 , 0.5%, 1 watt, wirewound:

220-0167       AUTO RANGING W/BARGRAPH               Faxback Doc. # 30486

To order parts call 1-800-843-7422 or visit your local RadioShack store.

Reference #             Cat.No.   Description                NP Part #
------------------------------------------------------------------------
                        11318615                             1N4148     
                        11332301                             2SC2500   
                        10526770  REPLACED BY 2SC2500        2TR0456   
BZ                      10553493  BUZZER,PIEZO BL-20B        BC0066     
X-TAL                   10595692  CRYSTAL,32.768KHZ          CX1144     
MOV1                    10621084  DIODE VARISTOR G220 METAL  DV0037     
                        10621084                             DV0037     
MOV2                    10621159  DIODE VARISTOR G390 METAL  DV0053     
                        10623528  REPLACED BY 1S2473         DX0684     
ZD1                     10630473  DIODE CA5010GN 1.2 VOLTS   DX3094     
                        10630473                             DX3094     
24                      10656098  CASE,BATTERY BLACK         HB0957     
                        10656098  HOLDER                     HB0957     
S2 S3 S4                10686434  RUBBER,SWITCH GRAY         HC6080     
                        10686434  RUBBER CONTACT             HC6080     
10                      10686442  COVER,BACK DARK BROWN      HC6081     
30                      10686459  COVER,LCD ACRYLIC          HC6082     
                        10696151  PKG OF 5                   HF0072     
                        10698512  5X20MM W/O PIGTAILS        HF1265     
18                      10768596  KNOB,ROTARY DARK BROWN     K2902     
25                      10768604  KNOB,POWER SWITCH RED      K2903     
28                      10800845  LCD,CG461                  LB0130     
                        10800845                             LB0130     
                        10824209  MANUAL,SERVICE 22-167      MS2200167 
                        10846418  XEROXCOPY                  MU2200167 
                        10913473  SURFACE MOUNT LARGE SCALE  MX7917     
HIC                     10934172  IC,HYBRID KD32 7 PIN SIP   MXP0901   
                        10934172  SINGLE IN LINE PACKAGE     MXP0901   
R22                     10939163  10    5%    2W    WWD RES  N0063EHH   
R5                      10944676  1.11M .5%   1/2W  MTF RES  N0579AFE   
R21                     10945392  4.99  .5%   1W    WWD RES  N0902AGH   
                        10955268  COEFFICIENT                NF0019     
VR-1                    10963122  POT,SEMI-FIXD 5K PT6KV     P0570     
                        10963122  HORIZONAL                  P0570     
VR-2                    10963130  POT,SEMI-FIXD 200K PT6KV   P0571     
                        10963130  HORIZONAL                  P0571     
VR-3                    10963148  POT,SEMI-FIXD 500 PT6KV    P0572     
                        10963148  HORIZONAL                  P0572     
2                       11849593  PLATE,RANGE                RA90034   
                        11849593  FOR FRONT PANEL            RA90034   
P S1                    11074754  SWITCH,PUSH POWER          SD0249     
                        11074754                             SD0249     
19                      11078755  SWITCH,CONTACT ROTATOR     SF0221     
                        11078755  ACETAL                     SF0221     
PAIR                    11107364  LEAD,TEST PAIR RED/BLACK   W0167     
                        11150752  PCB ASSEMBLY,MAIN          XB3703     
                        11150778  PCB ASSEMBLY,SUB           XB3705     
                        11200359  HOLSTER,RUBBER DARK BROWN  Z4483     
3                       11200649  PANEL,FRONT DARK BROWN     Z4540     
14                      11200656  STAND,DARK BROWN TILT      Z4541

[mzacharias]

If the "4.99 ohms" value is correct, you can parallel two 10 ohm resistors. Analog meters of this type simply aren't that critical. I don't know the history of this meter but since it obviously has been abused by burning out a current shunt, I wouldn't rule out other problems as well.

[subdude17349]

Great info, thanks very much!

I'm not ruling out other problems, but R21 was obviously smoked. And I can tell you with certainty that it hasn't been abused, I bought it new in 93 or so. Most of it's life has been spent verifying dc voltage or continuity. And BTW, it's not analog.

I have other meters, but just wanted to see if I could resurrect this one.

Again, thanks!

Jim

[mzacharias]

Great info, thanks very much!

I'm not ruling out other problems, but R21 was obviously smoked. And I can tell you with certainty that it hasn't been abused, I bought it new in 93 or so. Most of it's life has been spent verifying dc voltage or continuity. And BTW, it's not analog.

I have other meters, but just wanted to see if I could resurrect this one.

Again, thanks!

Jim

Well, at some time or another, it was touched to a voltage source while in mA mode, or the resistor wouldn't have burned. The good news is, it's not some eBay deal with an unknown history and possible multiple problems. Outlook is hopeful.