Mitsubishi non invater PCB problem

Omkar

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Discussion starter · #1 · Aug 1, 2025

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I hav

e a Mitsubishi non invater indoor PCB I'm trying to repair this PCB but I can't find any problem blower fan motor running 6 time red light blinking and after 5 minutes motor off after 3 to 5 minutes start again that is the problem I need help if anyone know about this problem please tell me

 

Sumerduck

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#2 · Aug 1, 2025

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Unit model number?

 

Omkar

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Discussion starter · #3 · Aug 1, 2025

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You can't guide me ?

 

Sumerduck

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#4 · Aug 1, 2025

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Just fishing for easy info

Rla505a001 seems to belong in:
DXE09ZMA-S 12ZMA
and
SRK-ZJS
...Whatever they are. The aren't showing up on Mitsubishi's US site

 

Sumerduck

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#5 · Aug 1, 2025

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I haven't found anything.

If the board is fine; the problem must be somewhere else in the cooling system

 

Omkar

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Discussion starter · #6 · Aug 1, 2025

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Problem is only with PCB because I already changed PCB now AC working fine but I have to repair this PCB

 

Sumerduck

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#7 · Aug 1, 2025

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If it's nothing you can test with probes, what does that leave? CPU and software?

 

C

Cyberninja

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#8 · Aug 1, 2025

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Omkar said:

I hav View attachment 891451
View attachment 891452
e a Mitsubishi non invater indoor PCB I'm trying to repair this PCB but I can't find any problem blower fan motor running 6 time red light blinking and after 5 minutes motor off after 3 to 5 minutes start again that is the problem I need help if anyone know about this problem please tell me

Click to expand...

It sounds more like a general failure with the current measurement of the blower on the old circuit board. Most controllers will have a software type overload that resets itself after a timeout period. Your observations sounds very similar to this. It could also be done with hardware on the board with a resettable thermal fuse. Those usually need to cool down after tripping. Thus the delay and eventual restart. If you have a service manual, you might start looking at that section on the circuit board.