PeakTech 9035 (power meter) - Page 1
Forum section: electronics / repair

author: Srbel
author_rank: Frequent Contributor
timestamp: November 17, 2015, 07:59:12 am
content: This is it:http://www.peaktech.de/productdetail/kategorie/engergiemessgeraet/produkt/p-9035.htmlLast time I have used it, it was working just fine. Then it just sat for a few months until I wanted to use it yesterday to found that it is no longer working.It turns on automatically when plugged into mains socket.Display is working. Time counter works. And it shows briefly mains voltage as 150Vac, then after a second around 50 Vac, and then after a second or so, 0V. Everything else is also shown as 0.Photographs are made with phone camera, so they are basically useless.There are two ICs, CS5460A-BSZ and HS24C02.CS5460A-BSZ:http://pdf1.alldatasheet.com/datasheet-pdf/view/255584/CIRRUS/CS5460A-BSZ.htmlFor other chip I can not find datasheet. On the chip it says:HS24C02A3AHOThe power meter has NiMh battery (3,6V 40mAh), which is dead (measures about 1,9V).It has two electrolytic caps. Smaller measures fine (with ESR@100Hz about 0,9 ohm), while bigger one while having a spot-on capacitance (220uF) measures ESR@100Hz of around 20 ohm. X2 rated cap seems fine.Diodes and current measuring coil check out fine.I find it a bit strange to have a battery there, because I don't know of any feature of this meter that would require it. I don't think it is for real time clock, because crystal frequency is 2,024 MHz and it is connected to the power meter IC (CS5460A-BSZ), while battery is connected to (HS24C02). Also, HS24C02 has all 4 pins on one side shorted together and connected to - of the battery. Is HS24C02 powered only from the battery, when mains voltage is detected, and that is why it no longer works? But I don't even know what does this chip do.Unfortunately, during work days, I have no time for anything, so I can only try to repair it during weekend. I will replace battery and 220uF cap then, but I was hoping that until then I can get some ideas on what else could be wrong with it.

author: retiredcaps
author_rank: Super Contributor
timestamp: November 17, 2015, 04:55:59 pm
content: Quote from: Srbel on November 17, 2015, 07:59:12 amPossibly serial EEPROM?http://pdf1.alldatasheet.com/datasheet-pdf/view/74863/MICROCHIP/24C02A.html

author: Srbel
author_rank: Frequent Contributor
timestamp: November 17, 2015, 05:31:30 pm
content: Could be. But it's not Microchip (maybe some knock off), it has some diagonal lines as a logo (which from distance at first I actually thought it was Microchip).It has 4 pins on one side all connected to - of battery, and some pins on the other side go to the LCD module.I have bought a replacement battery, and I will replace it tomorrow at work.

author: Srbel
author_rank: Frequent Contributor
timestamp: November 18, 2015, 06:38:29 am
content: Well, I have changed the battery, and it now works again.

author: tec5c
author_rank: Frequent Contributor
timestamp: November 18, 2015, 07:57:51 am
content: Try replacing the battery with a new one.Just kidding. What a nice and easy repair.

author: Srbel
author_rank: Frequent Contributor
timestamp: November 18, 2015, 08:42:12 am
content: Ha ha, yeah. The old one was 40 mAh, the new one is a bit bigger and 60 mAh.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: November 19, 2015, 04:11:51 pm
content: Glad you got it working.An ESR of 20 ohms does sound really high for a 220uF cap, though. Was that measured in circuit, or out of circuit? If in circuit then I wouldn't worry too much, as it is probably some other components.

author: Srbel
author_rank: Frequent Contributor
timestamp: November 20, 2015, 08:18:01 am
content: It was measured in circuit. But it was just a quick test. And DER EE DE-5000 LCR meter has big crocodile terminals and very short leads, so maybe the connection was not very good while measuring.I wanted to change that cap, but I don't have it in stock (50V 220uF).