On another Forum i noticed a person was charged $460 to get his Waeco fridge repaired as it wouldnt run on 240V. It had been running on aYamaha digital sinewave generator, this should not have been a problem. this got me thinking as i have a 3yr old CF-40 Waeco, what could go wrong with these powersupplys? I removed mine from the fridge & checked it out. First thing i noticed is a very small relay to automaticly change from 240V to 12V, its actually switching 24V from Powersupply to 12VDC, its ratings are240VAC 7Amp, to use it in a low voltage situation you can atleast halve its rating. This Relay is a potential cause of problems & dry solder joints on the board. If the 240V side of the power supply has been subject to over voltage there is a fuse soldered to the board worth checking. Next part that may fail in this situation is the 240V bridge rectifier ($5). Q1 is a IRFPC50 mosfet may also be damaged ($15) this is the most expensive part in the powersupply. There is also one capacitor that may fail C4 100Uf 35V. On the 24VDC side of the powersupply is 2 Caps that may cause problems eventualy if they dry out C16/19 2200Uf 35V. This powersuply is out of a 3Yr old CF-40 Waeco.
DeBe said
06:27 PM Apr 22, 2011
To bypass the 240v powersupply if nolonger working Remove Red+ wire from the DC socket & White + wire from the circuit board which comes from the powersupply. Run a thick red wire from the DC socket+ to the Circuit board + where the White wire was. The fridge should run on 12V now.
BobnBev said
08:21 AM Apr 23, 2011
Yes also saw that and wondered why some one would spend that amount getting it fixed when a new board would be much less than that.. Have a box full of bits just like that, they just need going over ..... Not many people will pull the back off their fridge and solder bits to it and change wires.... Have let the smoke out of a few at times..big smile.. Have a good easter ...... Bob
DeBe said
09:37 AM Apr 23, 2011
Hi Bob, Unfortunatly this isn the first time people have been charged that mutch to just replace the powersupply board. I suspect that it wouldnt cost mutch to repair the board.
BobnBev said
10:08 AM Apr 23, 2011
Very true, I have a lot of bits if you were looking for anything ,, Just give me a pm ....
DeBe said
12:46 PM Apr 23, 2011
Another potential fault in the powersupply is failure to start up. This can be caused by R2 100K 2Watt metal film resistor(10c part) It can go high in value or open circuit. Its used to kick start the SMPS at turn on.
DeBe said
12:15 PM Apr 30, 2011
Here is the circuit as an aid for anyone who is capable of repairing one. I should point out that the 24V DC side is isolated from the 240V AC side.
-- Edited by DeBe on Saturday 30th of April 2011 12:31:05 PM
DeBe said
04:40 PM Mar 17, 2012
To test a compressor & its module, remove wires from C & T then bridge them with a jumper. The compressor should run, this test was done on 12V if using the in built powersupply it will be 24V. The 2 top thick wires are also the best place to check for run voltage.
dorian said
05:24 PM Mar 18, 2012
Thanks for the useful info, DeBe. Much appreciated.
Cruising Granny said
06:50 AM Mar 21, 2012
The first sign of trouble when my Waeco 240V circuit board died wa a blown fuse. I replaced the fuse but it went again. So I'm running it on a transformer 240v-12v at the moment with a new circuit standing by to be installed.
Rippah said
04:05 PM Jun 17, 2012
Blew up my fridge on 240V a little while ago. My fault, using a mate's crappy $2 gennie, that will learn me!
Anyway, can anyone identify the capacitor that was in the red circle? All of it's mates are 472M and I'm assuming it's the same, however, it does appear to be a little smaller in size in other images.
DeBe said
08:48 PM Jun 17, 2012
Hi Rippah, The part is V1 & its a MOV, 7D431K. The replacement is avalable from Jaycar RN-3406 for $1.75. Its a surge protector which in an over voltage situation can be destroyed & blow the mains fuse on the board.
DeBe said
07:32 PM Jun 28, 2012
Hi, You should be able to remove it without shifting the compressor. The only parts i moved was bend one bracket as shown, & moved the reciever drier (cylinderical copper object with a capilliary tube coming from it.) The polly fuse is a light brown square thin object by the relay.
-- Edited by DeBe on Thursday 28th of June 2012 07:36:36 PM
habana said
01:28 AM Jun 29, 2012
I have a CF-50 which has the signs of a dodgy polyfuse and Waeco have confirmed from my serial number that it is one of those affected. Out of warranty of course and in any case there is no service agent where I live. I am/was an electronics engineer so I should have no problem fixing the PSU, particularly after DeBe kindly posted the circuit diagram. However, I know nothing about refrigeration and am a bit concerned about moving the compressor to a point where I can remove the PSU. There is obviously the possibility of damaging the possibly work hardened copper pipes that go up into the fridge. One of the photos above shows at least one of the rear mounting brackets bent back, presumably so the compressor can pulled out sideways rather than dropped down. Is this the way to proceed? Any help with pulling the thing apart would be appreciated.
DeBe said
02:55 AM Jun 29, 2012
Heres a pict of the Polly fuse.
habana said
03:29 AM Jun 29, 2012
many thanks DeBe. I'll look at it in the morning.
habana said
01:04 AM Jun 30, 2012
Hi DeBe.
I found the easiest way of getting the PSU out was a combination of your method and lowering the compressor about an inch. I replaced the polyfuse and the fridge works OK on 240VAC so I didn't break anything! I'll try it in the car tomorrow.
Many thanks for your help with this.
harvvectra2012 said
05:32 AM Aug 1, 2012
We have a Waeco brand electric cooler model CF-40. It came with our 2007 Winnebago Vectra when we bought it about a year ago. I've had it on in the past, but this is our first extended road trip and now it doesn't work. We're getting power both on the 120 volt & 12 volt circuits. The fuses both on the outside & inside of the box are good. We've got power to the power supply box and from the 26 volt power from the power supply box to the circuit board. Nonetheless, still no display on the control panel. No power light and no error light. I assume the board is bad. I can't find a schematic for the board (no manf. name only a number of 005224 REV:C). I can't even find a place to buy the board. We're hoping someone has had some experience with this problem or where to get help.
Hi Chris & Marily. Can you post a sharper picture of the other side of the circuit board? Possable places for trouble are dry solder joints around the Relay or the 2 Regulator ICs 7810 & 7805 at the top of your picture. The regulator 7810 should have 12 or 24V on one leg center leg goes to ground & the other should have 10V DC on it. With 7805 it should have 12/24Vdc on one leg, center leg ground, other leg should have 5V DC on it. Will put picture of a CF-40 board same as yours except it doesnt have the relay fitted as its on the Mains to 24V powersuply board.
ken thomas said
10:42 PM Aug 6, 2012
I have a problem with my Waeco on 240 volt as it made a sizzling sound when I turned the240 volt on and it blew the circuit breaker in the van and on the site power pole. I have not looked at it yet but it still works on 12 volt when there is power in the dual battery Ken
Dan said
02:22 AM Nov 14, 2012
Hi everyone,
I have been inspired to pull my waeco cf 50 out of the never to be seen again black hole in my shed as I think it has a blown polyfuse and would like to replace it. From what I have read I think need to replace it with a larger capacity one. Can anyone tell me what polyfuse I should use?
Cheers,
Dan
DeBe said
05:41 AM Nov 14, 2012
Hi Dan, i would try one from Altronics, PTC fuse R4562A for $1.50 they have a trip current of 7.5Amp.
bairsjw said
11:13 AM Dec 9, 2013
Hi i know its an old post, but was wondering if anyone can tell me either from experience or the circuit diagram what Uc3844 does. I have a blown one (wet foam had fallen on the MOSFET after replacing a thermistor) and there are 2 available on a search of the ic number on element14 that are nearly identical, the only difference one outputs 5v, the other 13.4 v. Can someone tell me which one is right? ( I've ordered both as they are only $2.60 each!) thanks in advance!
DeBe said
06:54 PM Dec 9, 2013
The UC3844 is a Switch Mode Power Supply driver IC. I would be using the original IC number. There is 3 other UC 38xx types which are different. The Mosfet may also be damaged.
bairsjw said
01:47 AM Dec 12, 2013
As mine is blown and the number is no longer viewable I searched using your picture but the number comes up with a couple of possibilities with different following letters ( not on the ic in the picture) the difference being the output voltage, any idea which one I should be using? I have also bought the MOSFET so will replace at the same time.
DeBe said
09:18 AM Dec 12, 2013
The UC3842 is a Switch Mode Power Supply driver IC. I would be using the original IC number. There is 3 other UC 38xx types which are different. The Mosfet may also be damaged. Here is the Data on the UC3842A controller chip, the Ic you are getting should match this, as far as I know there is only one UC3842A IC.
Have a box full of bits just like that, they just need going over .....
Not many people will pull the back off their fridge and solder bits to it and change wires....
Have let the smoke out of a few at times..big smile..
Have a good easter ......
Bob
Hi Bob, Unfortunatly this isn the first time people have been charged that mutch to just replace the powersupply board. I suspect that it wouldnt cost mutch to repair the board.
Another potential fault in the powersupply is failure to start up. This can be caused by R2 100K 2Watt metal film resistor(10c part) It can go high in value or open circuit. Its used to kick start the SMPS at turn on.
-- Edited by DeBe on Saturday 30th of April 2011 12:31:05 PM
So I'm running it on a transformer 240v-12v at the moment with a new circuit standing by to be installed.
Hi Rippah, The part is V1 & its a MOV, 7D431K. The replacement is avalable from Jaycar RN-3406 for $1.75. Its a surge protector which in an over voltage situation can be destroyed & blow the mains fuse on the board.
Hi, You should be able to remove it without shifting the compressor. The only parts i moved was bend one bracket as shown, & moved the reciever drier (cylinderical copper object with a capilliary tube coming from it.) The polly fuse is a light brown square thin object by the relay.
-- Edited by DeBe on Thursday 28th of June 2012 07:36:36 PM
I found the easiest way of getting the PSU out was a combination of your method and lowering the compressor about an inch. I replaced the polyfuse and the fridge works OK on 240VAC so I didn't break anything! I'll try it in the car tomorrow.
Many thanks for your help with this.
We're getting power both on the 120 volt & 12 volt circuits. The fuses both on the outside & inside of the box are good. We've got power to the power supply box and from the 26 volt power from the power supply box to the circuit board. Nonetheless, still no display on the control panel. No power light and no error light.
I assume the board is bad. I can't find a schematic for the board (no manf. name only a number of 005224 REV:C). I can't even find a place to buy the board.
We're hoping someone has had some experience with this problem or where to get help.
Thanks in advance for any help!
Chris & Marily
I have not looked at it yet but it still works on 12 volt when there is power in the dual battery
Ken
I have been inspired to pull my waeco cf 50 out of the never to be seen again black hole in my shed as I think it has a blown polyfuse and would like to replace it. From what I have read I think need to replace it with a larger capacity one. Can anyone tell me what polyfuse I should use?
Cheers,
Dan
Hi Dan, i would try one from Altronics, PTC fuse R4562A for $1.50 they have a trip current of 7.5Amp.
The UC3842 is a Switch Mode Power Supply driver IC. I would be using the original IC number. There is 3 other UC 38xx types which are different. The Mosfet may also be damaged. Here is the Data on the UC3842A controller chip, the Ic you are getting should match this, as far as I know there is only one UC3842A IC.
au.element14.com/jsp/search/productdetail.jsp
Pretty sure it's right!
au.element14.com/jsp/search/productdetail.jsp
This one should be fine as its specs are the same as the A, probably just a later version of the original.
Vout = Vref x (R18 + R19 + R20) / (R19 + R20) = 2.5 x (26.5 + 2.4 + 0.22) / (2.4 + 0.22) = 27.8V