[FIXED] Pls help me repair Advantest R6581 - Page 1
Forum section: electronics / repair

author: chihaxinh
author_rank: Regular Contributor
timestamp: July 14, 2016, 03:10:44 am
content: Hi everyoneI Have one Adavantest R6581 - 8 1/2 DMM i have same problem like deadlylover . But when change battery not help , after calibration battery quick dry out. And after some pow on - pow off ,all config lost.https://www.eevblog.com/forum/repair/advantest-r6581-8-5-digit-dmm-mini-teardownrepair/msg896924/#msg896924All semiconductor it's japanese production like Hitachi - Fujitsu - Toshiba and some part like memory or ROM RAM can't find datasheet.DMM have 2 transformer . And in bottom it's are of baterry and part like ram . I think some short like cap leak and diode short make battery quick dry out.Many thank your help !Best RegardsNam.

author: deadlylover
author_rank: Frequent Contributor
timestamp: July 14, 2016, 04:22:15 am
content: Have you tried probing around yet? There should only be a few components relating to the battery backup so it shouldn't be too hard, let us know what you find.I can take my unit apart mid/late next week if you need me to check some component values.

author: chihaxinh
author_rank: Regular Contributor
timestamp: July 14, 2016, 06:35:30 am
content: Quote from: deadlylover on July 14, 2016, 04:22:15 amDear Deadlylover , i haven't try probing around ! i haven't experience about complicated equipment repair . I see IDE cable from module Battery to GPIB inferface so i fear all Ram or like this relative with GPIB Module.To night i take apart and take clear picture !Many thank you !Best RegardsNam.

author: chihaxinh
author_rank: Regular Contributor
timestamp: October 29, 2016, 04:48:01 pm
content: Hi everyoneI have freetime and go back to repair Advantest R6581. When looking around and have some measurement i have some information.When power off, i checked battery using 1.4mA . Battery go to 1k drop resistor , and go to pin 2 - Maxim Max695, controlling battery power to CMOS Statics RAM . And in Output of MAX695 (pin 2 ) go to direct pin 28 of M5M5256DFP - RENESAS CMOS STATIC RAM.So if using mobile battery ( 3.7V 1200maH ) - i caculate have 1200/1.4 = 825 Hour ~ 32 Day.Do you thing MAX695 broken or Bad Statics ram ?Link to datasheet !http://docs-europe.electrocomponents.com/webdocs/12f6/0900766b812f6990.pdfhttp://datasheet.octopart.com/M5M5256DFP-70LL%23T0-Renesas-datasheet-7723.pdfThank you so much !Best regardsNam Nguyen Hai.

author: Kleinstein
author_rank: Super Contributor
timestamp: October 29, 2016, 05:41:27 pm
content: There are only very few parts in the battery powered section. So a broken CMOS ran is a possible candidate. but also the max695 could be bad. I would guess it is easier to remove the max695. IT might be enough to isolate only a power pin to measure the individual current.Other parts to check can be capacitors in that area.1.4 mA is way to much - should be more like 1.4 µA.

author: singapol
author_rank: Frequent Contributor
timestamp: October 30, 2016, 04:16:34 am
content: This might be helpful to know Fix this and figure out things later.QuoteOriginally from:https://www.febo.com/pipermail/volt-nuts/2013-August/002767.html

author: chihaxinh
author_rank: Regular Contributor
timestamp: October 31, 2016, 02:30:01 am
content: Hi everyoneI Checked pcb, very nice and dont have any broken traces . So i will order Max695 and statics ram , it's take about 5-6days .When finish replace , i will inform to everyone final status.Many tksNam.

author: chihaxinh
author_rank: Regular Contributor
timestamp: November 08, 2016, 06:41:08 am
content: Hi everybodyWhen componant part I order arrived . So it’s time to repair DMMIt’s picture on front DMM. I don’t have DSLR Camera so I take picture by mobile phone.When take out cover case . It’s locate battery and memory location.You can see have to ribbon cable from Display Panel to PCB , and have IDE cable go to GPIB ModuleLocation of battery insideWe can see have one big capacitor , 1 big Bridge Rectifier , some smd Bridge Rectifier. All cap good and don’t leak.CloserBack pcbPCB design very good and all track very tiny, about 5mil wide.Very hard to take out ribbon cable, if using hard force, you can break pfc connector and cable . All connector it’s smd connector.When I try three or four time, I finish take out ribbon cable. And complate take out pcbSome picture closer?We can see Xilinx chips, 2 advantest chips, I thing it’s micro processor , beside advantest micro chips it’s statics dram .And here it’s battery are , Max695 beside Cap 470uF , and below it’s 2 statics SRAM M5M56256I hasty replace all Max695 and static ram because i dont want to collapsing again.And bingo , same problem. Memory Function using 1.5mA , same before replace ? This ít’s my mistake don’t double check again.After 30 minute checking again , Battery line go to Epson RTC62421 , and in Pin 17 18 19 of Epson RTC62421 have one short cemramic bypass capacitor.I don’t know value so I replace by 100nF ceramic capacitor.Test check current again and Bingo ? Take 5uA ( Before 1500uA )To night I reassembly in cover and check running state . Hope in repair step don’t make broken other part.All picture you can see in link belowhttp://imgur.com/a/s5dfIMany thank all support !Best RegardsNam Nguyen Hai

author: chihaxinh
author_rank: Regular Contributor
timestamp: November 09, 2016, 01:54:22 am
content: Hi everybodyAfter repair , my DMM working well, take 15min to running internal calibration . Now equipment running very well !Hope DMM running for long time ( arount 2-3 year ). Next maintain cycle we hope need recap only !Many thank all support !Best RegardsNam Nguyen Hai