Service manuals, schematics, eproms for electrical technicians
COMARK 1905 INSULATION METER 1971 SM
Type: 
(PDF)
(PDF)Size
376.5 KB
376.5 KB
Page
2
2
Category
METER
SERVICE MANUAL
METER
SERVICE MANUAL
If you get stuck in repairing a defective appliance download this repair information for help. See below.
Good luck to the repair!
Please do not offer the downloaded file for sell only use it for personal usage!
Looking for similar comark manual?
Good luck to the repair!
Please do not offer the downloaded file for sell only use it for personal usage!
Looking for similar comark manual?
Advertisements
Document preview [1st page]
Click on the link for free download!
Document preview [2nd page]
Click on the link for free download!
Advertisements
Please tick the box below to get download link:
- Also known:
COMARK METER 1905 INSULATION 1971
- If you have any question about repairing write your question to the Message board. For this no need registration.
- If the site has helped you and you also want to help others, please Upload a manual, circuit diagram or eeprom that is not yet available on the site.
Have a nice Day! - See related repair forum topics below. May be help you to repair.
Warning!
If you are not familiar with electronics, do not attempt to repair!
You could suffer a fatal electrical shock! Instead, contact your nearest service center!
Note! To open downloaded files you need acrobat reader or similar pdf reader program. In addition,
some files are archived,If you are not familiar with electronics, do not attempt to repair!
You could suffer a fatal electrical shock! Instead, contact your nearest service center!
so you need WinZip or WinRar to open that files. Also some files are djvu so you need djvu viewer to open them.
These free programs can be found on this page: needed progs
If you use opera you have to disable opera turbo function to download file!
If you cannot download this file, try it with CHROME or FIREFOX browser.
Translate this page:
Relevant METER forum topics:
Sziasztok Kollégák!
Kis segítséget kérnék a fenti műszer javításához..
Egy hűtőgépes ismerősömé és szeretnék segíteni rajta...
A lényeg,hogy sípol kb.5másodperc alatt 15-öt,a piros led világít.
Ezután felgyorsul a sípolás és a led a sípolás ütemében villog.
Gondolom ilyenkor érzékeli a szivárgást?!
Ez mitől lehet?És egyáltalán hogy és mit érzekel ez a cucc?:-)
Elnézést,ha pongyolán fogalmaztam.Remélem azért érthető volt..
Köszönöm a figyelmet.
Üdv Tomi
http://granat-e.ru/tif-xl-1.html
In my case the display of the ScopeMeter was frozen and the keyboard did not respond any more exept the on/off key. This happened always after the ScopeMeter has been switched on for a while. To find the temperature effect, I heated up the different parts of the Digital A1 board with a hair dryer. At some point, the device display stopped working completely and only the backlight was working. This effect was steady and irreversible.
To repair the device, you need the "fluke_92b_96b_99b_105b_servicemanual" provided here in the service manual area.
On page 272 in Figure 9.2b (Digital A1 circuit diagram, part b) the display contrast circuit schematic shows the NPN Transistor V1432 of type BC848C (see also the attached picture). Measuring the Base/Emitter diode showed a low resistance of 100 Ohms in both directions. Replacing that transistor by a NPN transistor of type BC847C solved the problem and the device was working correctly again.
The reason for choosing the BC847C instead of the BC848C are the Vcbo and Vceo of only 30 V of the BC848x series. The BC847x series has a Vcbo of 50 V and a Vceo of 45 V respectively and offers therefore a greater margin. The V1432 is placed between TP431 (LCDPWR, +5 V) and the -30 V connection from Analog Board A2. These conditions are too close to the absolute maximum ratings of the BC848x and are especially for higher temperatures critical.
To repair the device, you need the "fluke_92b_96b_99b_105b_servicemanual" provided here in the service manual area.
On page 272 in Figure 9.2b (Digital A1 circuit diagram, part b) the display contrast circuit schematic shows the NPN Transistor V1432 of type BC848C (see also the attached picture). Measuring the Base/Emitter diode showed a low resistance of 100 Ohms in both directions. Replacing that transistor by a NPN transistor of type BC847C solved the problem and the device was working correctly again.
The reason for choosing the BC847C instead of the BC848C are the Vcbo and Vceo of only 30 V of the BC848x series. The BC847x series has a Vcbo of 50 V and a Vceo of 45 V respectively and offers therefore a greater margin. The V1432 is placed between TP431 (LCDPWR, +5 V) and the -30 V connection from Analog Board A2. These conditions are too close to the absolute maximum ratings of the BC848x and are especially for higher temperatures critical.
Üdv mindenkinek!
Vettem egyik kollégától egy, a fennti cimben megadott tipusú, pc oszcilloszkópot.
A készülék müködik, miután nagy nehezen sikerült feltelepitenem win xp alá (eredtileg win95-ösre készült).
Ám van vele egy kis gond: az ábrázolt jel nem stabil, van egy lassú vizszintes remegése. A belső tápban a kondikat ellenőriztem és jók (ESR).
Valahogyan az az érzésem, hogy ez nem programhiba, hanem a szkóp, szinkron áramkörének hibája, mert ha igy lenne, akkor nincs más mód, igy fogom használni, mert a javitás szóba sem jöhet kapcs. rajz nélkül, ugyanis ilyesmit nem találtam a neten.
Ha valakinek lenne véleménye vagy tapasztalata e témában, kérem segitsen.
Elöre is köszi.
Becze Zsolt.
Sziasztok mesterek!Velemenyeket szeretnek kapni evvel a szkoppal kapcsolatban TR-4655/2A 50MHz,meg szeretnem vasarolni,az egyeduli baja hogy a jel nem tolti ki a telyes kepernyot,vagyis ketoldalt (jobbrol es balrol megjelenik 2 cm ures sav,szeretnem tudni ha orvosolhato-e es megeri vele foglalkozni,(elnezest az ekezeteket nem tudom kiirni a billentyuzet miatt) koszonom elore!!!