fujitsu AOH45LJBYL

[install monkey]

help!!!!

was asked to look at a underceiling unit- infra red controller- flashy indoor led's timer continuous rapid flash (every 1/2 second) and operation (red led) flash 5 times
indicating comms error

disconnect wire 3 on outdoor-comms and 60-130vac pulsed (ok) when connected onto terminal 3 pulsed 50-70vac
240v present on cn34 which is pcb supply off noise filter- diagnosed outdoorr pcb- 300 quid later-returned and fitted- noticed that terminals on rectifier was marked cable colours- noticed a chunk missing off main inverter chip- powered up- popped control fuse on pcb- turns out compressor dte!!!- waited 6wk for compressor-turned up with smashed suction stubb!
3 days later- new compressor inspected ok- attended site and replaced compressor,power board, rectifier, fired it up- still gettin comms error between indoor outdoor!
when powerin it up u hear a noise of the pcb powerin up- all fuses ok- obviously the fault would reset itself once powered up- pullin me hair out- cant see indoor pcb faulty, and something appears to take out the outdoor pcb once powered up!- if tayters has any service manuals, or would fancy a weekend up north-on site! haha

http://www.climastorm.com/service/General/floor/service/272_ABH45L.pdf
unit is listed as general- old r410a- does say indoor pcb comms error??

[The Viking]

Hmm,

If the fault blew the original outdoor PCB and you powered it up with the faulty inverter board and the new outdoor PCB...

Did you fit a 2nd new outdoor PCB when you replaced everything else?

:cool:

[install monkey]

original board flty- i replaced pcb due to comms error and found comp dte- so replaced compressor and fitted new outdoor pcb, rectifier and power board, lookin at the manual it shows indoor comms error! climate ctrs fault list in the air con book shows description as comms error.
it mentions that the outdoor pcb has a red l.e.d that will flash if fault- but never seen any of em flash up- should be 1 flash for comms error

[Tayters]

Man, love a trip up north, Drugs, crime, poverty. Told us about things like that in school.

Read LJBYL, fit fan motors, controller (inverter PCB) and ACTPM (active filter module - little chap with black plastic outside). Original metal body motor were crud and have a habit of spiking the PCB when a power surge or if power turned back on. Something about dodgy diode in the motor. Newer motor is white plastic body and pukka.

To prove outdoor circuit is ship shape just follow the voltage through the boards.

240V AC from mains to W1, W2 on power supply board.
240V AC out on TM101, TM102 through posistor to diode bridge.
300 ish V DC out of diode bridge to + and - on ACTPM
Out of ACTPM on P and N (blue and yellow wires) at a 300 to 340V DC to W107, W108 on main PCB

If AC there but no DC then probably posistor is working due to fault in circuit.
Disconnect blue and yellow from main pcb and see if DC voltage there. If not work back unplugging stuff. When voltage appears and this will show what component is causing the fault. If voltage appears when blue and yellow removed then either faulty PCB or component plugged into it faulty - remove components in turn to prove. Make sure board powered down for a few minutes before removing fan motors! Make sure both fuses good - check voltage across them on back of board.

CN34 is 240 supply for RV and comms chip. DC for the main board (high and low voltage) comes from blue and yellow and proper important.

If the voltages are fine and you can hear the EEV inialising then outdoor side of things probably fine.

Was there any comms voltage from indoor?

On top of all that got to say again about the metal fan motors. Leave at your peril...

[install monkey]

comms with wire 3 disconnected off terminal 3 on outdoor unit was 60-130vac pulsed then when connected on terminal 3 it was 0-60vac- oh just remembered ive got andys guide to inverter testing!;)

Man, love a trip up north, Drugs, crime, poverty. Told us about things like that in school.

Read LJBYL, fit fan motors, controller (inverter PCB) and ACTPM (active filter module - little chap with black plastic outside). Original metal body motor were crud and have a habit of spiking the PCB when a power surge or if power turned back on. Something about dodgy diode in the motor. Newer motor is white plastic body and pukka.

To prove outdoor circuit is ship shape just follow the voltage through the boards.

240V AC from mains to W1, W2 on power supply board.
240V AC out on TM101, TM102 through posistor to diode bridge.
300 ish V DC out of diode bridge to + and - on ACTPM
Out of ACTPM on P and N (blue and yellow wires) at a 300 to 340V DC to W107, W108 on main PCB

If AC there but no DC then probably posistor is working due to fault in circuit.
Disconnect blue and yellow from main pcb and see if DC voltage there. If not work back unplugging stuff. When voltage appears and this will show what component is causing the fault. If voltage appears when blue and yellow removed then either faulty PCB or component plugged into it faulty - remove components in turn to prove. Make sure board powered down for a few minutes before removing fan motors! Make sure both fuses good - check voltage across them on back of board.

CN34 is 240 supply for RV and comms chip. DC for the main board (high and low voltage) comes from blue and yellow and proper important.

If the voltages are fine and you can hear the EEV inialising then outdoor side of things probably fine.

Was there any comms voltage from indoor?

On top of all that got to say again about the metal fan motors. Leave at your peril...

[install monkey]

went back today- tested everything-all ok, still grounding the comms when indoor is powered- 112vac on wire 3 disconnected and connected on terminal 3 0-66vac tried with every component disconnected- proved 330vdc on blu and yellow- spoke to the polish bloke at fujitsu- he recommends - as did tayters replacing both metal fan motors and outdoor comms pcb- power pcb up with new fans disconnected to prove comms and to see red led on outdoor pcb steadily flash then connect fan motors- as a precaution i ensured condenser fan blades werent welded to the shaft with rust and age- tried spinnning both motor shafts with my hand- and the f**kers didnt spin too well- awaiting on authorisation for another 500 quids worth of bits and will update

[Tayters]

With the comms disconnected is that 100 odd V AC from the terminal and the wire, i.e comms from indoors and outdoors? Normally the comms voltage when all wired in is 70-120V AC if both units are communicating and around the 50V mark if only one unit is communicating.

[install monkey]

comms disconnected at outdoor - signal wire removed off term 3 tested earth to the bare wire (signal from indoor) 110v ac pulsed, when reconnected onto term 3 earth to 3- 0-67vac - no flashy led- no lev chatter- just a click of a relay

[install monkey]

compared to a nearby unit-same model- terminal 3 with wire connected 110v ac- flashy led

[Tayters]

comms disconnected at outdoor - signal wire removed off term 3 tested earth to the bare wire (signal from indoor) 110v ac pulsed, when reconnected onto term 3 earth to 3- 0-67vac - no flashy led- no lev chatter- just a click of a relay

Did you test comms between earth and the terminal 3 on the outdoor with the wire disconnected just to prove comms from the outdoor unit alone?
Anyway, no LEV chatter and low comms when wire connected sounds like outdoor controller PCB testicled.
Don't know how you get on changing the controller PCB but was on a site with that Fujitsu tech. His method was to take out the complete black electrics box. A few more bits to undo but easier with all this upside down malarky. He should know anyway, must have changed hundreds of the things! Oh and on a pub quiz trivia note he's Egyptian and a black belt in karate.

Cheers,
Andy.

[install monkey]

his english is better than mine,have fitted 2 of these boards already-so i can do it blindfolded- love it when they stick pcb's upside down and u have to disconnect wires as theyre too short- then addin heat sink paste- then getting covered in it

[ozairman]

help!!!!
noticed a chunk missing off main inverter chip- powered up- popped control fuse on pcb- turns out compressor dte!!!- waited 6wk for compressor-turned up with smashed suction stubb!
3 days later- new compressor inspected ok- attended site and replaced compressor,power board, rectifier, fired it up- still gettin comms error between indoor outdoor!
when powerin it up u hear a noise of the pcb powerin up- all fuses ok- obviously the fault would reset itself once powered up- pullin me hair out- cant see indoor pcb faulty, and something appears to take out the outdoor pcb once powered up!

I'm late to the party here but I have worked on many of these in a previous life.

I am guessing the control fuse you are talking about is F2 the 3.15A one in the middle of the board that is hard to get to? If so it has nothing to do with the compressor being down to earth and all to do with the fan motors which you are now thinking are suspect.
The noise you mention on power up, is it a sort of a high pitched squeal? if yes then it is the switch mode power supply in the middle of the main board protesting loudly and in its death throes.

Has the F2 fuse blown on the last board you fitted?

The best way to test the DC fan motors instead of spinning them is to use a digital multimeter on diode check mode. These motors have their own inverter drive in the back and are a little 3 phase motor. So when you test them you are not measuring windings but checking semiconductor components on the inverter drive board in the back of the motor. The Red lead is the high voltage DC supply to the motor, the Black is the DC ground and the White is the 15 VDC supply, the Yellow is the speed signal from the PCB and the Brown is a feedback to the PCB but you are only interested in testing the power leads.

Check between the Red-Black leads and the White-Black leads, making sure you test in both directions/polarities. With an average Fluke multimeter a good motor with no shorts will give a reading like 0.8v/O-L on Red-Black and 0.4v/1.1v on White-Black. Any readings that are the same both ways or you get the short circuit beep indicate a shorted fan motor that is toast.

If the motor just shorts out on the Red-Black leads it will most likely blow the F2 fuse but not damage the board. If the White-Black leads are shorted then it will also blow the F2 fuse and most likely have damaged switch mode power supply on the board and knocked out all of the low voltages that the machine needs to work (18 VDC for the ACTPM, 15VDC for the fan motors and IPM control, 12VDC for the EEV power relay and 5 VDC for the Microprocessor and all the thermistors).

As Tayters has said the metal case motors could be better described as hand grenades with loose pins.....

If the F2 fuse has blown on your control board you can try changing it to see if the board comes back to life. It can be done without disassembling the inverter assembly as there is a hole in the bottom of the inverter case. If you look up into the inverter from where the main inductor coil is mounted on the panel between the compressor and condenser fans you can see the F2 fuse. A long screwdriver in from the front where the fan motors plug in to flick the blown one out and then use a piece of 10-12mm wooden dowel about 300m long with the end cut of at a 45° angle and some blu-tack to hold the new fuse in place on the end. Poke it up through the hole in the base and poke the new fuse into the clips. Or modify a set of long nose pliers with long handles to do the job if you want to be fancy.

Checking the serial signal voltages on terminal 3 of the interconnects is not 100% reliable and some later outdoor boards did not seem to send signals until they had received communication from the Indoor. The sound of the power relay clicking and the EEV initialising are probably a better guide, to the health of the outdoor unit. You can check for High and low voltage DC on the control PCB by testing on the back of the fan motor connectors CN800 and CN801, Pin 1 = HV DC, Pin 4 = DC Ground, Pin 5 -= 15 VDC. If you want to check for the 5 VDC then Pin 1 of each thermistor plug is 5VDC when referenced to the Blue from the ACTPM or Pin 4 of the fan motor connector.

The Power PCBs rarely fail except for when mice and geckos get on top and short them out, or a power surge blows the varistors. On the odd occasion the current transformer goes out of whack and the machine will not ramp up to maximum current draw.

When you changed the PCB's did you make sure that you connected the power relay leads up from the main PCB to the power relay under the Power PCB? Also active and neutral haven't been crossed over anywhere or it will mix up serial signal testing.

Also when changing the Boards the most reliable way to do is it to remove the black carrier with the Inverter and Power PCB's on it as Tayters said he had seen done. It doesn't take long and you can make sure that everything gets routed correctly, especially the control wires to the ACTPM and the heatsink thermistor. I've seen lots of the Inverter boards with blown IPM's where those wires had been trapped under the IPM, in that situation the machine normally works for a few hours after the board has been changed then the IPM overheats and lets out the smoke.

Hopefully I haven't rambled too much, and some of this is useful to you.

[install monkey]

yes the pcb did do the squeel then pop went the lil fuse , i did replace it and no squeel - im waiting on authorisation for the fan motors and another pcb. got the service manual but it doesnt give u much info regarding fault finding/testing.
after the first pcb replacement i tested the compressor and insulation to earth at 250v setting was 0.0meg- direct short

I'm late to the party here but I have worked on many of these in a previous life.

I am guessing the control fuse you are talking about is F2 the 3.15A one in the middle of the board that is hard to get to? If so it has nothing to do with the compressor being down to earth and all to do with the fan motors which you are now thinking are suspect.
The noise you mention on power up, is it a sort of a high pitched squeal? if yes then it is the switch mode power supply in the middle of the main board protesting loudly and in its death throes.

Has the F2 fuse blown on the last board you fitted?

The best way to test the DC fan motors instead of spinning them is to use a digital multimeter on diode check mode. These motors have their own inverter drive in the back and are a little 3 phase motor. So when you test them you are not measuring windings but checking semiconductor components on the inverter drive board in the back of the motor. The Red lead is the high voltage DC supply to the motor, the Black is the DC ground and the White is the 15 VDC supply, the Yellow is the speed signal from the PCB and the Brown is a feedback to the PCB but you are only interested in testing the power leads.

Check between the Red-Black leads and the White-Black leads, making sure you test in both directions/polarities. With an average Fluke multimeter a good motor with no shorts will give a reading like 0.8v/O-L on Red-Black and 0.4v/1.1v on White-Black. Any readings that are the same both ways or you get the short circuit beep indicate a shorted fan motor that is toast.

If the motor just shorts out on the Red-Black leads it will most likely blow the F2 fuse but not damage the board. If the White-Black leads are shorted then it will also blow the F2 fuse and most likely have damaged switch mode power supply on the board and knocked out all of the low voltages that the machine needs to work (18 VDC for the ACTPM, 15VDC for the fan motors and IPM control, 12VDC for the EEV power relay and 5 VDC for the Microprocessor and all the thermistors).

As Tayters has said the metal case motors could be better described as hand grenades with loose pins.....

If the F2 fuse has blown on your control board you can try changing it to see if the board comes back to life. It can be done without disassembling the inverter assembly as there is a hole in the bottom of the inverter case. If you look up into the inverter from where the main inductor coil is mounted on the panel between the compressor and condenser fans you can see the F2 fuse. A long screwdriver in from the front where the fan motors plug in to flick the blown one out and then use a piece of 10-12mm wooden dowel about 300m long with the end cut of at a 45° angle and some blu-tack to hold the new fuse in place on the end. Poke it up through the hole in the base and poke the new fuse into the clips. Or modify a set of long nose pliers with long handles to do the job if you want to be fancy.

Checking the serial signal voltages on terminal 3 of the interconnects is not 100% reliable and some later outdoor boards did not seem to send signals until they had received communication from the Indoor. The sound of the power relay clicking and the EEV initialising are probably a better guide, to the health of the outdoor unit. You can check for High and low voltage DC on the control PCB by testing on the back of the fan motor connectors CN800 and CN801, Pin 1 = HV DC, Pin 4 = DC Ground, Pin 5 -= 15 VDC. If you want to check for the 5 VDC then Pin 1 of each thermistor plug is 5VDC when referenced to the Blue from the ACTPM or Pin 4 of the fan motor connector.

The Power PCBs rarely fail except for when mice and geckos get on top and short them out, or a power surge blows the varistors. On the odd occasion the current transformer goes out of whack and the machine will not ramp up to maximum current draw.

When you changed the PCB's did you make sure that you connected the power relay leads up from the main PCB to the power relay under the Power PCB? Also active and neutral haven't been crossed over anywhere or it will mix up serial signal testing.

Also when changing the Boards the most reliable way to do is it to remove the black carrier with the Inverter and Power PCB's on it as Tayters said he had seen done. It doesn't take long and you can make sure that everything gets routed correctly, especially the control wires to the ACTPM and the heatsink thermistor. I've seen lots of the Inverter boards with blown IPM's where those wires had been trapped under the IPM, in that situation the machine normally works for a few hours after the board has been changed then the IPM overheats and lets out the smoke.

Hopefully I haven't rambled too much, and some of this is useful to you.

[nanalai]

Maybe this can help :

[install monkey]

how??????????

Maybe this can help :