FAULT FINDING

Continued from page 55 of fault finding

Is LED 1 and LED 2 flashing and LED 3 on?

yes

no

Is LED 1 and LED 2

on and LED 3

flashing?

yes

Allow the boiler to

cool. Is the

resistance of the flue temperature probe

<600 Ω ? yes

Replace the probe and press the reset button

no

no

Is LED 1 on and LED 2 flashing?

yes

Remove the flue

temperature probe. Is the resistance of the probe > 30 KΩ ?

yes

Replace the probe and press the reset button

Is the harness in short circuit?

yes

Replace faulty wiring

no

no

no

Is LED 1 on and

no

 

Is LED 1, LED 2

 

yes

Replace faulty

LED 2 and LED 3

 

 

 

 

and LED 3 on?

 

 

 

PCB

flashing?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

no

 

Has the main

no

 

Is there continuity of

 

Repair or replace

overheat thermostat

 

overheat thermostat

 

 

 

damaged wiring

 

 

 

operated? (Check

 

 

 

 

wiring at PCB

 

 

 

 

continuity)

 

 

 

 

connection?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

yes

 

 

 

 

 

yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Allow boiler to cool

 

 

 

 

Replace faulty gas

 

 

 

 

and press re---set

 

 

 

 

valve

 

 

 

 

 

 

 

no

 

 

 

 

 

 

 

Is the continuity of

 

Replace faulty wiring

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the flue temperature

 

 

 

 

 

 

 

 

 

 

probe harness OK?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Replace faulty PCB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Check the

 

 

 

 

 

 

 

 

 

 

recuperator

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FAULT FINDING

Wait for 1 minute. Is the fan still running?

yes

Is there continuity

across C and NO on

the Air Pressure

Switch?

yes

Is the Air Pressure Switch harness continuity O.K?

yes

Is the burner on?

yes

Repair or replace

faulty flame

detection signal

connection harness.

Refer to frame 49.

no

no

no

no

Is there 230V at

the fan

connections?

yes

Replace faulty fan.

Are the sensing

pipes undamaged and connected?

yes

Is the flue clear and

venturi O.K?

yes

Replace faulty Air

Pressure Switch

Repair or replace

faulty wiring.

Replace faulty PCB

no

no

no

Is there continuity between NC and C at the

Air Pressure Switch?

yes

Is there continuity of the

Air Pressure Switch

harness?

yes

Replace faulty PCB

Replace sensing

pipes.

Clear flue

Repair or replace

venturi

no

Replace faulty Air

 

 

Pressure Switch.

no

Repair or replace faulty wiring.

mini HE --- Installation & Servicing

57

Page 57
Image 57
Mamiya C32, C28, C24 manual Fault Finding

C28, C24, C32 specifications

The Mamiya C series is celebrated among photography enthusiasts for its unique twin-lens reflex (TLR) design, offering both a classic aesthetic and innovative features that set it apart in the world of medium format cameras. The C32, C24, and C28 models represent a range of technology and design advancements that cater to various shooting needs.

The Mamiya C32, introduced in the early 1970s, is renowned for its precision engineering and versatility. This model features interchangeable lenses, allowing photographers to switch between different focal lengths for creative flexibility. The camera supports 120 and 220 film formats, enabling higher film capacities for extended shooting sessions. An essential feature of the C32 is its built-in light meter, which enhances exposure accuracy by providing real-time readings. The camera's bright waist-level finder offers excellent viewing comfort and composition aid, attracting those who appreciate a more hands-on shooting experience.

Next in line, the Mamiya C24 offers a slightly more compact and lighter design, making it an appealing option for documentary and street photographers. While still featuring the electronic leaf shutter system utilized in the C32, the C24 omits built-in metering, which encourages users to develop their exposure skills. The lens selection remains robust, with options ranging from wide-angle to telephoto, allowing for creative versatility. The C24's rugged build quality and reliable shutter performance make it a trusted companion in various shooting conditions.

Lastly, the Mamiya C28 provides a perfect blend of portability and advanced capabilities. With its ergonomic design and improved lens coatings, the C28 offers enhanced image quality with better contrast and sharpness. Similar to its predecessors, it utilizes an interchangeable lens system but enhances user convenience through quick-to-use shutter speeds and aperture settings. The camera is also compatible with a range of accessories, such as flash units and close-up attachments, further expanding its creative potential.

In summary, the Mamiya C32, C24, and C28 each present unique features and technological advancements that cater to various types of photographers. Whether it's the precision of the C32, the compact convenience of the C24, or the versatile performance of the C28, these cameras maintain a special place in the hearts of medium format enthusiasts, showcasing the blend of craftsmanship and innovation that Mamiya is known for.