Hotpoint FFA47X Fridge Freezer

[stj]

Re: Hotpoint FFA47X Fridge Freezer

unless you want 25meters of it, i wouldnt get wire from RS

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

unless you want 25meters of it, i wouldnt get wire from RS

Good point. Tinning is the answer then albeit I didn't want to strip the insulation off a multi strand.

Lesson learned from blowing the triacs up though as made me cautious. Referring back to the PCB pictures, will it matter what diameter the wire is because when I used the thick copper single strand as a jumper across the evaporator defrost terminals that is what blew the PCB to smithereens!

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

Gutted.

Have done the triacs and a tinned six strand wire and the display is still dead!

Do I spend more time on it or buy a new fridge? Problem is it's a big fridge and it would be top end of £700 for same storage size and...

I hate being defeated!

Addition Information: I think the triacs are properly soldered in. I found another capacitor which had blown obviously during the voltage surge which blew the triacs and I have found some resistors which although I haven't checked resistance bands yet they appear not to be giving ANY reading in circuit whilst others are. Obviously need to work out their rating, desolder one leg and check them again but it seems suspect with no reading whatsoever.

[stj]

Re: Hotpoint FFA47X Fridge Freezer

take a look at that pic, clean up those solder splat's - one looks like it's shorting something.
and put some plastic under the jumper so it wont arc to the stuff under it.

after that, meter all the supface mount resistors - the 3rd digit is the multiplier.
so 103 = 10k

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

take a look at that pic, clean up those solder splat's - one looks like it's shorting something.
and put some plastic under the jumper so it wont arc to the stuff under it.

after that, meter all the supface mount resistors - the 3rd digit is the multiplier.
so 103 = 10k

Thank you.

I've taken a look through a 10x jewellers loupe and solder splats look OK and I have metered for continuity across tracks that should be connected.

I've tested the majority of 103 SMT Resistors and the two marked in the edited photo appear faulty or blown. Yellow circle reads 0.00. Red square one reads 1.000 on a 20K scale.

I have a Precision Gold PG017 DMM and it measure weirdly I think. When on 20K scale, I get 10.00 for a 103 SMT.

Some other SMT Resistors further down read either 561 or 195. It's impossible to tell but they are reading 0.28 on the 20K scale so presumably 280

Also, how would I know whether these resistors are 1206 or 0603 or otherwise please?

[keeney123]

Re: Hotpoint FFA47X Fridge Freezer

Does that mean they are DC or AC when they have the white strip?



That'll be the two lines of copper dots then on the top right of the meter!

The white strip with the - on it is the negative side which would mean it is a DC Cap. The AC caps are not mark with polarity as the voltage is changing back an forth . Sorry I did not see the other pages.

[keeney123]

Re: Hotpoint FFA47X Fridge Freezer

Thank you.

I've taken a look through a 10x jewellers loupe and solder splats look OK and I have metered for continuity across tracks that should be connected.

I've tested the majority of 103 SMT Resistors and the two marked in the edited photo appear faulty or blown. Yellow circle reads 0.00. Red square one reads 1.000 on a 20K scale.

I have a Precision Gold PG017 DMM and it measure weirdly I think. When on 20K scale, I get 10.00 for a 103 SMT.

Some other SMT Resistors further down read either 561 or 195. It's impossible to tell but they are reading 0.28 on the 20K scale so presumably 280

Also, how would I know whether these resistors are 1206 or 0603 or otherwise please?

The first two numbers are just that numbers and the other is how many zeros are after it. So 56 with one zero after is 560. I am looking at this bare wire on your board is that touching any other connection that it is not suppose to? Also, the resistors have to have one leg desoldered and lifted to get the correct reading.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

The first two numbers are just that numbers and the other is how many zeros are after it. So 56 with one zero after is 560. I am looking at this bare wire on your board is that touching any other connection that it is not suppose to? Also, the resistors have to have one leg desoldered and lifted to get the correct reading.

Thanks for your input.

My point was I am unsure whether it is 561 or 195. It is impossible to tell.

The bare wire is not touching any component. I wanted to use insulated wire but was advised to tin bare wire instead.

It's surely impossible to desolder one leg of an SMT Resistor? The others which are soldered are nearly bang on. The lowest reading I obtained was 9940 Ohm on a 103

[Behemot]

Re: Hotpoint FFA47X Fridge Freezer

That's almost 10k so it's OK. There is some tolerance, +-1 or +-5 %.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

But what about post #105, Behemot?

[Behemot]

Re: Hotpoint FFA47X Fridge Freezer

I have a Precision Gold PG017 DMM and it measure weirdly I think. When on 20K scale, I get 10.00 for a 103 SMT.

That's OK again. For those which read something else check if there is not something in parallel with that, otherwise desolder and check out of circuit. It is not easy but possible, just use enough solder flux and quickly heat one and other end all over again till it gets loose. Sometimes there is glue beneath so you need some other tool to help it.

[vinceroger69]

Re: Hotpoint FFA47X Fridge Freezer

as per post 105 Also, how would I know whether these resistors are 1206 or 0603 or otherwise please.
im not sure how you tell this either maybe behemot can advise us?

[stj]

Re: Hotpoint FFA47X Fridge Freezer

0603 = 1.6mm x .8mm
0805 = 2mm x 1.25mm
1206 = 3.2mm x 1.6mm

[vinceroger69]

Re: Hotpoint FFA47X Fridge Freezer

Thanks again stj.

[keeney123]

Re: Hotpoint FFA47X Fridge Freezer

Thanks for your input.

My point was I am unsure whether it is 561 or 195. It is impossible to tell.

The bare wire is not touching any component. I wanted to use insulated wire but was advised to tin bare wire instead.

It's surely impossible to desolder one leg of an SMT Resistor? The others which are soldered are nearly bang on. The lowest reading I obtained was 9940 Ohm on a 103

You just need to lift the resistor enough to slide a thin piece of plastic between the board and the resistor lead. Also, a 1.9 MOhm resistor is not a common size I would expect it to be 560 ohms which is a common size. Sure way to tell is to desolder and measure. Also, did that track burn up where you replaced it with that bare wire?

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

I would expect it to be 560 ohms which is a common size.

Thank you. It is reading 280 so I'll leave that for now as a 103 reading 0.00 is clearly not right.

Also, did that track burn up where you replaced it with that bare wire?

Yes. Like an idiot I used single core copper wire to jump across the evaporator defrost terminals thinking it need a signal to say something was plugged in! Vapourised the track and blew the triacs to smithereens.

Before that, I got it working for a few days apart from the compressor was not kicking in.

I bought a service information manual. Cost me £32 for 30 pages of dross which cannot be retained to Hotpoint because it is special order. To boot, it looks like a colour photocopy and contains no real useful information about diagnostics.

[keeney123]

Re: Hotpoint FFA47X Fridge Freezer

So was the compressor not being told to kick in? or is the compressor bad? The refrigerator should have a defrost timer. This should be either mechanical or electrical. If it is mechanical then this is a common problem. They get stuck in defrost mode so the compressor will not kick in. If mechanical some times you can turn it manually until the compressor kicks on again.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

So was the compressor not being told to kick in? or is the compressor bad? The refrigerator should have a defrost timer. This should be either mechanical or electrical. If it is mechanical then this is a common problem. They get stuck in defrost mode so the compressor will not kick in. If mechanical some times you can turn it manually until the compressor kicks on again.

Compressor is fine as I spoke to a AC friend of mine and he said to check if the coils are warm and they are.

The compressor wasn't working when I fixed the PCB so I'm not sure what that would indicate but once I blow the PCB to bits, the compressor started working but it doesn't switch off because it is not getting a signal through the PCB I guess.

The reason for the post was to initial fix the display IIRC. I replaced 3 capacitors and BINGO! I did that but the unit was not working still.

I've tested the fans. They are fine.

It's just a case of whether I can get the PCB fired back up.

I have ordered a variety of SMD creamic resistors and they are arriving today.

Pretty sure my skills are not good enough to solder SMD at the moment. I think they are 0603. I suppose I could interchange them with 0805 where I have space (or does the whole base of the case on an SMD have to be soldered to the pad to get the correct resistance - I guess not).

A couple of the resistors as per a few posts back are not reading so that is where we are currently with the resurrection project.

[keeney123]

Re: Hotpoint FFA47X Fridge Freezer

estion, is the refrigerator cold as the compressor is now working? The compressor will not turn off until it reaches temperature or you turn the setting inside to as warm as it will get. I take it that the the coils you are mentioning are on the back of the refrig. and not the coils inside the freezer compartment? As those inside coils are the defrost. To solder a surface mount resistor you can just tack one side down. If using rosin core solder you can just tin the tip of the iron and then touch one side of the resistor while holding down the resistor with the index finger of the other hand. Once one side is tack down you will be able to free both hands to solder the other side of the resistor. Then you can come back an solder the tack side once the other side is cooled and will not move. In order to solder, the object is to heat both pad and lead of device at the same time. It is a good idea not to apply solder right at the site the tip is touching but a little ways away in order to make sure the joint is properly heat to prevent a cold solder joint. Of course with surface mounted it requires very little heat unless the board has different plains inside of the board. With solder that has no flux in it's core I would put some flux down on one pad and tin the pad then take a pair of pointed nose pliers, pick up the resistor where the leads aren't then heat the pad while at the same time setting the resistor lead on it. Take the iron away while still holding the resistor there until it cools. To desolder on Surface mount board I would use solder braid. You would put flux on the joint then put the braid on the joint and apply soldering iron to braid. Move the soldering iron up and down the braid until you removed the solder. Also, you can add a little solder to the joint if the braid is not picking the old solder up. Just don't leave the iron there until you damage the pad.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

keeney123. Thank you for the advice. I will apply that when I pick the resistors up on Monday.

To see where I am with this and it will answer your questions. Refer back to Post 70. There are a couple of photos in the following posts and you will see and understand how I have now damaged the main PCB I am trying to repair.