Hotpoint FFA47X Fridge Freezer

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

Also I would like to check Q17 ACS108 triac which I believe is a TO-92 format ( from data sheet) but wondered if I use EEPROM ground and then proved each leg would it give me a voltage reading or, with EEPROM running around 5V, would it blow something to smithereens again if I probe a leg of a component which I believe should be getting 240VAC.

I am guessing something special must happen with a DIGITAL VMM because the probe leads are thin and unable to take 600Vac so I am guessing the current is somehow reduced inside meter? I suppose what I am trying to find out is does a meter transfer a current large enough to blow a component if pribes are placed willy-nilly across random components.

This is why I am fearful of testing when I don't fully understand.

[stj]

Re: Hotpoint FFA47X Fridge Freezer

the 4 pads that are linked together are N
the next one after the gap is L

you should be able to find parts on the top of the board that connect with them you can reach with your meter.

if your standing on a chair, and the unit is empty, i would just throw it on it's side instead.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

Aha! So trace 2 is the live and 7-11 are neutral. Opposite to what those previous so-called experts who I sent the board to thought.

Can you explain to me why if I have the probe on trace 2 and probes 7-11, I only get full voltage on trace 7?

Are you referring to the traces on my last photo, stj?

[stj]

Re: Hotpoint FFA47X Fridge Freezer

THIS should help.

[budm]

Re: Hotpoint FFA47X Fridge Freezer

The primary DC circuit GND ref for measuring the DCV in the primary will be the negative leg of the main filter cap.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

The primary DC circuit GND ref for measuring the DCV in the primary will be the negative leg of the main filter cap.

Is that the 400V radial cap or one of the Epcos caps?

[stj]

Re: Hotpoint FFA47X Fridge Freezer

400v radial electrolytic should meter about 345vdc across the pins.

[budm]

Re: Hotpoint FFA47X Fridge Freezer

https://www.badcaps.net/forum/showpo...7&postcount=51

The board has more than one power supplies, one is isolated switching power supply which is the one that supplies the Voltage for the EEPROM, other is non-islolated.

[keeney123]

Re: Hotpoint FFA47X Fridge Freezer

There seems to be a disagreement between Stj and BudM display of what is neutral and line. These things are important if you also have a ground. This is why I ask you does your electrical plug have a ground connector and does your receptacle have a ground connector?

[budm]

Re: Hotpoint FFA47X Fridge Freezer

The L and N are based on OP marking (you see the black L, N markers) which I believe the OP got that from the wiring digram.
But after looking at the wiring diagram:
https://www.badcaps.net/forum/showth...t=46668&page=3
I believe the OP had it wrong, pad 7 is L. so the L and N in my drawing is reversed.

[stj]

Re: Hotpoint FFA47X Fridge Freezer

right now, i just want to know if AC is reaching the board!

[budm]

Re: Hotpoint FFA47X Fridge Freezer

Looking at service manual page 32 connection diagram, pin 7 is LINE (BROWN), pin 12 is N (BLUE 2) which are connected to the AC power cord, it does not show any fuse in line for protection.

[stj]

Re: Hotpoint FFA47X Fridge Freezer

that dont mean much given u.k. power cords have a fuse in the plug, and he dead shorted the board so could have burned a connection someplace.

[budm]

Re: Hotpoint FFA47X Fridge Freezer

All he has to do is to check the fuse in the plug and also check the resistance between the L blade to the board pad 7, and N blade to the board pad 12, they should be <1 Ohm.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

The L and N are based on OP marking (you see the black L, N markers) which I believe the OP got that from the wiring digram.
But after looking at the wiring diagram:
https://www.badcaps.net/forum/showth...t=46668&page=3
I believe the OP had it wrong, pad 7 is L. so the L and N in my drawing is reversed.

I'm not qualified to have an opinion. Take a look at post 183. I was beginning to think they were wrong.

I had no idea what those numbers were for on that diagram but how do you? There are 11 pads in that area of the PCB so how can we be sure?

I wish I could strip the casing back!

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

All he has to do is to check the fuse in the plug and also check the resistance between the L blade to the board pad 7, and N blade to the board pad 12, they should be <1 Ohm.

Sadly, it's impossible to get in with my probes!

I know it won't rule out a problem with the new truacs I have soldered in but from this photo is someone able to tell me if pad 2 traces to any of the big solder reservoirs once triacs are active ( or do the fans cause them to become live when they get a signal )?

I'm obviously thinking how I can check power to the nearest component connected to any trace that needs checking given that the U/s of PCB is tight to fridge but protrudes slightly.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

Pad 7 shows continuity to the big solder reservoir pad at the rear of the triac where I soldered the jump wire to so I would be able to access that. Pad 2 continuity stops at triac leg obviously because, I assume, it's not powered and therefore not switched until power is applied.

[stj]

Re: Hotpoint FFA47X Fridge Freezer

the display should work even without the new triacs, although it may be related to the one that fits from the other side of the board.
but that is not the problem,
because you have no power to the logic chips (eeprom & cpu)

[budm]

Re: Hotpoint FFA47X Fridge Freezer

Did the fuse in the AC plug blow?
BTW, you said you cannot get the probe to the board to check the continuity between pin 7 and pin 12 against the AC plug so how did you manage to measure the dc Voltage on the EEPROM?
BTW, the MOV is connected between the LINE and NEUTRAL so you should be able to solder the wires to the MOVE legs to allow you to take the measurement.

[Rhothgar]

Re: Hotpoint FFA47X Fridge Freezer

Yes the fuse in the plug is fine.

The freezer still gets cold but to -30 deg C And I did measure 240V across two pads a few posts back. Checked it anyway and it is OK.

EEPROM on far left next to buzzer on top of board. GND and Vcc pins face out.

Uploaded photo of u/s board too so you can see roughly how much of the board sticks out.