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jaceace
13-05-2013, 01:02 AM
Hi All,

Just wondering if someone can point me in the right direction, I was changing the base on a Mitsubishi Heavy. I did not disconnect any cables or copper when i changed the base as it took 3 of us to lift the condenser,compressor and everything else onto the new base.

So after repairing all the panels and making it look like new, we installed it and I get a error light on the outdoor board which is error light 5. It blinks 2 times.

I have checked all sensors, there are 3 of them i get 52.5k ,5k,5k on the sensors.
I have checked the power onto the resistor PCB and i get 300v dc onto the board, but nothing going to the compressor when it calls for it.

The resister board does have visible corrosion on the board. Board bellow
10347

what i don't understand is that the unit was working fine before a removed it? When I put it back it had had an issue.
I have also disconnected the compressor from the board and tried without it. But it gave the same error. The fan on the outdoor starts up, but when it calls for the compressor it goes into error. The main PCB is fine.

I have inserted the service manual in case i have missed something.

Has anyone got any other ideas on what the issue could be? Any help would be greatly appreciated.

I think its the resistor pcb, unless something else is holding it out on the main pcb as it communicates between CNL and CNK.

Thanks

nike123
13-05-2013, 03:35 AM
You probably have issue with "cold solder" somewhere on PCB because of corrosion. It would be advisable to re-solder all.

http://upload.wikimedia.org/wikipedia/commons/a/a0/Cold_solder_joint.jpg

jaceace
14-05-2013, 08:02 AM
Hi Nike123,

Thanks, I might try that as I just called up to order a new part and its $717.76 plus postage for that board :eek:. I am not sure the client will pay that for the board.

nike123
14-05-2013, 08:14 AM
If you don't have proper tools for re-soldering (temperature controlled soldering tip), it is better to take it to someone who has it and know how to use it!

jaceace
14-05-2013, 09:18 AM
Does anyone else have any ideas?

install monkey
14-05-2013, 08:01 PM
2 time flashes: Power transistor overheat
• Fastening of the power transistor to the heat dissipation fins
(tighten the screws, apply silicone) is insufficient.
• Power transistor is defective.

jaceace
14-05-2013, 10:35 PM
Thanks install Monkey, the board above in the picture is the power transistor board. The unit is 10 years old and is 1 street back from the beach. The unit was suffering from corrosion. The unit times out and LED 5 flashes twice after 3 minutes of being switched on. The outdoor fan comes on, would you know what voltage should be on the CNL and CNK cables from the main pcb?

I am pretty sure its the power transistor board, but at a $717.16 replacement i would like to be 100%. I am going back today to do some finale testing.

jaceace
15-05-2013, 12:10 AM
Maybe I should suggest to the client he invests in a new system, I did not mention that the service valves were leaking gas and I have temporarily stopped the leaking but can not say it will hold. The board needs replacing and R22 gas is being phased next year. And I would say due to the age and location of the units (on the beach) this system is going to cost allot in repairs from now on. O and before i forget, one of the upstairs indoor units has a problem as well which is board related as well. I can not get to that until i get the system fired up.

Gosh reading all that sounds like I opened up a can of worms.

Only problem is that all the pipe work and electrical was installed when the house was built so its all in the walls. The house is an odd shape and makes it very very expensive to replace.

RBM
18-05-2013, 11:34 AM
I would replace the unit, 10 years is a good run for a unit near the beach if you can run the new pipes externally it would be better as they will experience the same problem again in a few years so pipe work needs to be accessible. I look after a resort on the beach they get about five years out of a unit at best.
good luck