Microwave oven with burnt Paraller resistors at PCB

[CapLeaker]

Re: Microwave oven with burnt Paraller resistors at PCB

RJ is right. You really can't measure the voltage drop, but you did verify that it isn't shorted. So that is a step in the right direction.

As for the other part:
CHN is the manufacturer
D100N is model
H02L power rating
Y1C429 maybe some date code or something.

To test that, I put: D100NH02L into Digikey. It came back it is a N-Channel Mosfet, 24V, 60A. STD100NH02L made by STMicroelectronics.
BTW: is that Mosfet shorted?

[budm]

Re: Microwave oven with burnt Paraller resistors at PCB

"at this relay CHP11-A240S
Multimeter into Pin's no#1 and no#2 gives Ohms: 14,53 or 14,71 depending of my 2 Multimeters, when selector @ 20K
those pin's have the "winding symbol" between them."
14.53K relay coil winding resistance? That cannot be right for 24Vdc (rated at about 1/2W) Power relay coil.

[cagiva4ever]

Re: Microwave oven with burnt Paraller resistors at PCB

.......
To test that, I put: D100NH02L into Digikey. It came back it is a N-Channel Mosfet, 24V, 60A. STD100NH02L made by STMicroelectronics.
BTW: is that Mosfet shorted?

hi !

thanks. for continued help. progress is made.

for the IXO Mosfet, i do not know for sure yet if it is "shorted". i havent taken it of de-soldered it yet from pcb. im not either very "happy" how the soldering looks like at the Mosfet on the pcb, basically it looks like non-complitely reflowed, as it has been hot...

without me googling 1st, may i ask if its possible to Measure it if i take it of the pcb ?

i have never yet had a broken power mosfet in my hands. i think i had 1 in my "Mascot adjustable pwr source", but a friend fixed that for me in the early days of my hobbyes.


tomorrow i see if i get to go to neighbour town component shop. i found out that i do not have used spare after all. buying1 from eBay will take 2~3weeks to arrive. same for MWO power relay if ordered, so a lot of time in hand.

this is what its like to live in a Arctic Circle backforest....

top of this my Washing machine dropped its inner Drum last week. i godda dismantle the complite machine later at Spring time. no washing now for 2months
i found a very good youtube video, so i know what to do with it.




For "budm" :

i measured the bare Relay alone, as is, at table, directly between pin#1 and pin#2.

sorry, did i do something wrong ?

EDIT: i will re-measure it and this time with the Correct Ohms range chosen from m-meter. sorry i was stupid.

let me know if i must-need take a photo or something to show.

buying new oem spec Matching relay from eBay will take 2~3weeks to arrive, so a lot of time in hand for me to Learn.


People, feel free to say to me, how to do things so that they are intresting and good for you readers and helpers to participate with. so that it would not be annoying to readers and helpers. i say this just in case if its a risk to be so.

[cagiva4ever]

Re: Microwave oven with burnt Paraller resistors at PCB

so basically what happened is "lost in translation"...

my multimeter(s) dont have the "auto ranking" for range settings. the CHP11 relay gave readings only on 20K range. i left out to mention that, sorry.

so it seems that the CHP11 is broken after all, no matter that i said "having good one at spares". it seems to have huge Resistant, summink broken shorted on the Core of it as i cant see any outside visible damage on magnetic winding and its copperwire solderings etc.

so that i would understand what the simular'ish size shape Magnetic coil(s) have for winding Resistance, i measured 1 of my (analog) motorcycle indicator relay(s). 12Vdc 22W. its coil ohms were 85,2 Ohms

id guess the coil has aboutish 500~1000 turns of winding in summink 0,10~0,05mm cage wire.

so now, i have parts ordering to do. tomorrow i know more.


while all this i have read "budm" sig link into LM7805 etc type regulators. and googled various Pwr Mosfet pdf's 50+ pages.

https://www.utm.edu/staff/leeb/mostest.htm

funny or not, my past fixed projects none have had as breefly mentioned before broken LM regulators or Mosfets, but most likely waiting future projects at closet do have them...

and what comes to my diy o-scope, it is basically designed for vehicle ign electronics use.

if some1 european happens to read this topic, feel free to offer me forsale them 4ch basic Bench o-scope, i will take offers. dont need to be Mint or modern. broken fixable is also taken ok.

[budm]

Re: Microwave oven with burnt Paraller resistors at PCB

The relay Wattage rating per spec at max is about 0.5W, so for 24VDC coil, the DCR of the relay coil will be about 1100 Ohms, so if it shows 14K Ohms, that will be bad and that means the replay'contacts were never closed to bypass the resistors.

[cagiva4ever]

Re: Microwave oven with burnt Paraller resistors at PCB

hi ! ^^ thanks for info

the CHP11 pwr relay mentioned is from another MWO, not from this MWO in case at this topic. just in case.....

i read now more about diff coil ohms ratings. was now easyer to spot the right column thx to your latest post..
en-g5Le.pdf

i have in past dismantled 2 diff MWO's which from i have spares left. iirc 1 mwo was working good and other was broken. so this CHP11 was apparently from the broken1 as i had not tagged left notes to them spares, as i always usually do.



ps.
anyone familiar with them diff ways how IC chips fail ? regarding white powder'ish surface all over at chip. Not dust. difficult to google, no results.

i wonder (if) why would Manufact sandof the type model markings of Chips surface.

only couple weeks ago i found bought from fleemarket a "german" mikroscope, with usb ocular function. maybe i can rescue the markings from IC with it.

for people who wonder why i write "alot" and do less , is that i have my equipment and projects etc scattered in 2 diff houses apart..

[CapLeaker]

Re: Microwave oven with burnt Paraller resistors at PCB

There are some manufacturers that grind of the top of the IC in order to protect their interest and market. So when that thing breaks, you have to buy a new board or send it in for service, while being charged like crazy. Nothing new.
Here is an example I dealt with very recently:
Some outfit in the US would like to charge me CAD$250 in order to send me ONE network jack from a audio codec. Last time I checked a network jack (even with magnetics) is like 9$ at Digikey. Problem was it had magnetics inside and the manufacturer did not want to release a schematic or any information on which exact layout that Ethernet jack has. I did figure it out after a while what it was, but that I find that is gauging the dumb Canadian as they would sell it to any US address for 140$. Yeah, a 110$ on freight(!!!) and customs for that Ethernet jack, that you could stick in a padded envelope or real small package, which costs like one Dollar to send via mail. Pissed me right off. Why would one pay even a 140$ on a Ethernet jack??? Is that now a cash grab or robbery?

[budm]

Re: Microwave oven with burnt Paraller resistors at PCB

hi ! ^^ thanks for info

the CHP11 pwr relay mentioned is from another MWO, not from this MWO in case at this topic. just in case.....

i read now more about diff coil ohms ratings. was now easyer to spot the right column thx to your latest post..
en-g5Le.pdf

i have in past dismantled 2 diff MWO's which from i have spares left. iirc 1 mwo was working good and other was broken. so this CHP11 was apparently from the broken1 as i had not tagged left notes to them spares, as i always usually do.


ps.
anyone familiar with them diff ways how IC chips fail ? regarding white powder'ish surface all over at chip. Not dust. difficult to google, no results.

i wonder (if) why would Manufact sandof the type model markings of Chips surface.

only couple weeks ago i found bought from fleemarket a "german" mikroscope, with usb ocular function. maybe i can rescue the markings from IC with it.

for people who wonder why i write "alot" and do less , is that i have my equipment and projects etc scattered in 2 diff houses apart..

So did the relay has bad coil per your Ohm reading? I do not quite understand about the new and old MWO comment.

[cagiva4ever]

Re: Microwave oven with burnt Paraller resistors at PCB

hi ! thx for info.

that is 1 pricy "jack". comes to my mind a price of a handshake at neighbour town with a Electrician repair man, "off the books" 70euro's for a handshake barely a consultation.

i might get lucky as the IC chip i mentioned has 3 digits still visible at the surface, its not "sanded" deeply. hence i didnt 1st seriosly think it was sanded, as 3 other Chips are normal showing numbers. (Benton smart charger car/auto)


So today i visited the Town component shop. i spend on parts a 25days food money.

MWO pwr relays was not available, and so was IXO pwr Mosfet. only from special order and price 5~10x ebay prices per qty:1 item.

had to back of even from special order as that would have been food money for yet another 10days.

at Trip i scored freeby cell phone spares, shop had scrapped phones with Charger jack's, speakers etc very common parts. i have been fixing mobile phones for past ~7years...


Cheapest ebay pwr relay ive found so far is:

http://www.ebay.com/itm/10PCS-SANYOU...AAAOSw5cNYLfjt

but but, it has ratings written in the box in diff order, and mising the Vdc rating 28 or 30.

i guess this is a Manufac chosen writing layout, or it it not match to mine from "Zanty" ?

more googling to do unless, someone has that easy said from knowlidge memory in seconds.


or how about this1 ? difference at 10A 125Vac VS. on mine 15A 125Vac.
here in eu we have the 50/60Hz 230vac households.

http://www.ebay.com/itm/PCB-Power-Re...sAAOSwIwhWSEui

5-pin model, but usable no matter pin amount.
http://www.ebay.com/itm/5Pcs-SRD-24V...4AAOSwtnpXiNiF

or OMRON G5LA-14 24VDC
5-pin
http://www.ebay.com/itm/OMRON-Power-...IbYy5lbHx7sk0g

[cagiva4ever]

Re: Microwave oven with burnt Paraller resistors at PCB

So did the relay has bad coil per your Ohm reading? I do not quite understand about the new and old MWO comment.

CHP11 relay is a sparepart relay from Another MWO, which 2nd MWO i have dismantled Prior. this had ~14,5 @ 20Kohms selector. relay is broken. so i cant use it as a sparepart.

Zanty brand relay that has side burn on its box casing is from the MWO in case that im now repairing. i have earlyer written this from it ZANTY relay:

-i now Multimeter resistance measured the "Burned" power relay while it is IN at pcb.

zener diode and the normal diode "orientation" Block any other component to interefere with measurement, so id say its ok to measure while it is IN at pcb.

edit:06.03-2017
only the small capacitor is "actively" in same circuit, connected Paraller at side of Relay core winding. capacitor is empty, no charge its been without power now for 1+ year.

Multimeter gives readings that jump walk allover, start from ~1300 and go down into zero, flickering.... "


So id say that Zanty relay is broken, which is same what you have speculated before i did any measurements, when you originally explained to me what could be the reason for burned paraller resistors.

of course unless the Zanty measured while attached into PCB, has intereference from other components on the PCB.
But why would it show Ohms readings that Flicker and jump up&down going into zero-0. no stable reading from it.

i havent de-soldered the Zandy of the PCB (yet), as i have my tools in 2 diff houses, not in hand available. i was in thinking that its ok to measure it while its IN the PCB.



Next step to me is to Order buy the suitable NEW pwr relay, hence the Post prior thisone from me, with ebay options to choose from the rightone.

[budm]

Re: Microwave oven with burnt Paraller resistors at PCB

"Zanty brand relay that has side burn on its box casing is from the MWO in case that im now repairing. i have earlyer written this from it ZANTY relay" That is probably due to heating because of contact resistance (failed contacts).

[cagiva4ever]

Re: Microwave oven with burnt Paraller resistors at PCB

the Zanty relay has Burning on its external surface at the boxcasing Because the Paraller resistors that Burned, burned the side of the relay.

them paraller resistors got so hot that they burned the Zanty external surface.
because other of them resistors was skinclose to the Relay at the PCB layout space.


So, people feel free to tell me what Relay i should choose from those Ebay linked ones, please. takes 4working days to topup my Paypal account, so ~5days to choose.

i should also ebay search the Pwr mosfet D100N H02L. (bosch IXO screwdriver)

[budm]

Re: Microwave oven with burnt Paraller resistors at PCB

Relay: some stuff of what you should look for
1) PCB footprint has to match.
2) Pin-out for the coil and the contacts has to match.
3) Coil Voltage should match.
4) Coil Wattage should not be higher than the original.
5) Contacts Voltage and current rating should be the same or higher

[cagiva4ever]

Re: Microwave oven with burnt Paraller resistors at PCB

R_J how did you manage to find the Zanty datasheet pdf ? i cant find anything from Zandy as pdf.

as far as i understand the Zandy pdf that you earlyer linked is not complite.
ive been now many hours googling without any luck, ive now used also 2nd OEM pwr relay specs for datasheet but no luck. info midway below.

i think that This exact Zanty relay i have has Coil resistance of 1300ohms (its what my Flickering test also shows at start.

Best replacement Pwr Relay brand would most likely be OMRON.
Omron_G5LA-14 coil resistance is 1600ohms. and Wattage consumption approx ~0,36 . Zanty has same consumption.

Thing is that i found a Holy Grail regarding this exact PCB card from Russian forum. it has alot of details principal explanations, here has been said same but breefly.

at the russian source forum, Fixer used OMRON. his MWO was 800 Watts, where as mine is 700W

https://a.d-cd.net/f08fdfcs-960.jpg

OMRON G5LE-14
24Vdc
10A 250Vac
5A 250Vac
0383W9
1440 Ohms coil resistance
power cinsumption 360~400mW
5-pin Relay put works, Zanty is 4-pin.
https://cdn.badcaps-static.com/pdfs/...7af9701ca5.pdf
https://cdn.badcaps-static.com/pdfs/...7dd68da454.pdf


i wonder that 4-pin VS. 5-pin hasnt got any working difference then on the latch-switch-viper what to call it, its position.

Let use this photo as a Sample. i mean the switch between Pin's #2 and #4 at this SAMPLE photo, sample purpose.
http://foxtango.org/FT-102/images/G2U-112P-US.JPG

at 4-pin relay will it differ from 5-pin for "stock position" or functional working. i say ask this as the Russian was using 5-pin instead of 4-pin Stock.



i also have found 2 other OEM original pwr relays used on this exact same PCB board model like My mine, which from other is:
PHOENIX MECANO
OKS2C-SDC24V
24VDC
Max 10A DC
https://lh5.googleusercontent.com/-K...0/IMG_7081.JPG


3rd relay brand/version OEM is at single photo that i have. but now i have enough to go cope with.

Other people had same part Failures as i have (common typical to the Design) but also some had D1/D2 Diode failure also.


Original Zanty's at Taobao
https://world.taobao.com/item/876747...?fromSite=main

Russian forum info's
http://monitor.espec.ws/section37/topic107904.html
https://www.drive2.ru/b/1661655/
https://a.d-cd.net/570fdfcs-960.jpg

[budm]

Re: Microwave oven with burnt Paraller resistors at PCB

Your circuit only requires SPST (Single Pole Single throw) that has Common (C) pole and Normally Open (N.O.) Pole, you can then have another relay with same form factor with pin for the SPDT (Single Pole Double Throw) which will have one more N.C. (Normally Closed )contact, so if the PCB has 5-PIN footprint for the same form factor then you can install 4-pin relay into the PCB which if you look at your PCB, the footprint is for 5-pin relay. Most relay current rating for N.O. and N.C. will not be the same.
I will not go lower current than the original.
Zanty (ZTU series) UL RATING OF 15A @120 VAC, TuV rating of 10A @250 VAC but not clarify to what kind of load type.
Omron UL (40c) @TuV (85c) rating with resistive load is 10A ( general use for UL) 250 VAC. So it should work.

[cagiva4ever]

Re: Microwave oven with burnt Paraller resistors at PCB

MWO SUMMARY:

im now on the very final stretch, actually 1-click (*done ordered) away from ordering qty:2 suitable Pwr Relay's. found finally after spending like 30+ hours on web, the suitable and cheapest source. not that i anyway found more than 3 suitable Relays from eBay.

i have found also yet 2 more pwr relay photos and Box casing data used on exactly same PCB as mine, on MWO's ranking from 700W and 800W. 6 different MWO brands models found with same specific PCB.

i have now the Scale for up/low end RANGE of the relays used on these PCB's.

seems that the easyest manufac to Substitute is "Tianbo HJR-3FF-xx". this company seems to have FAR THE best availability for DataSheet's on web.



http://www.tianbo-relay.com/ProductC...page=1&catid=3

surprise surprise eBay's currently most sold Pwr relay happens to be exactly Tianbo HJR-3FF. 10x more than others sold.



Among all these 4~5 Pwr relays (24vdc 1600ohms) found as OEM on the PCB, have same specs:
-magnetic Coil DCR(ohms) 1600
*even thow my broken Zanty started to flicker from 1300 ohms
-magnetic coil power consumption 0,36W
-Max switching voltage either 28Vdc or 30Vdc. (if anything is mentioned it seems to be 28Vdc, so its at the bottom of the Min tolerance range)
-and Coil driver current 15,0 mA being mentioned as typical for 1600ohms DCR coil.


i have made an data collection and written word document with all data found and photos etc.


So now, its 3-weeks to wait for the Pwr relay to arrive, thumps up.

and for now, shall i pull out another project as IXO is waiting for Mosfet to be founded from eBay...its tricky bit to find at all from eBay.

if people intrested, i could take into inspection "Adjustable Mascot Powerunit" or the "12Vdc into 100W 230vac output inverter unit".

afaik "Mascot" is known from music and gaming applications.

[xaruqui]

Hi cagiva4ever, any news? I'm having exactly the same issue -and same PCB as well-

I've replaced both resistors with the same fate than the originals and I didn't think the relay was causing it, but now I'm having doubts... I also couldn't find anything about this Zanty relay.

Expecting good news from you.

Thanks.

[stj]

Re: Microwave oven with burnt Paraller resistors at PCB

ha respect!!
first member from the new country of Catalonia - to hell with the globalists!

[xaruqui]

ha respect!!
first member from the new country of Catalonia - to hell with the globalists!

Thank you for your support! In fact there's nothing wrong about globalism as long as there's mutual respect, which I haven't seen from spain for a long time... But let's not talk about politics here, we'll do it in another forum

[xaruqui]

Re: Microwave oven with burnt Paraller resistors at PCB

Hi there. In case there's someone having the same issue: I received the new relay last week and I just replaced it (along with the parallel resistors). The microwave is working.

As it turns out, while desoldering the original relay I realized that one of its coil contacts was cut/broken inside the casing, thats the reason why the resistors kept burning no matter what. This relay is no longer available so I replaced it by a similar one.

Relay specs:

JQC-3FB 024-1Z141
220VAC/10A

Good luck.