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SMT reflow oven typical trouble shooting




Heat slowly

1. broken hot air motor

2. wheel and motor don’t join well

3. short circuit of SSR output

1.check hot air motor

2. check blower

3. replace SSR

4. heating for longer time

High temperature for long time

1.broken hot air motor

2. broken blower

3. Shorted circuit of SSR output.

1. check hot air motor

2. check blower

3. replace SSR

The machine can’t be started

1.Upper oven doesn’t close

2. “Emergency stop” is not ready

3. “start” is not on

1.check conveyor switch

2. check “Emergency stop”

3. press “start”

Temperature can not reach setting value

1.broken heater

2. broken thermocouple

3. short circuit of SSR output

4.unbalanced exhausting capacity

5. Broken photoelectric partition in the controlling panel.

1.replace heater

2. replace thermocouple

3. replace SSR

4. adjust exhausting capacity

5.replacephotoelectric partition 4N33 5 heating for longer time

Abnormal conveyor motor, SSR shows that conveyor is overloaded or something blocked

1.restart thermal overload relay

2 check and replace thermal overload relay

3.reset electronic current of thermal overload relay

1.red lamp is on

2 all the heaters stop running

Dual-screw system stops running

1.Broken conveyor switch

2. “Emergency Stop” is not ready

1. Check conveyor switch

2. Check “Emergency Stop”

Count imprecisely

1.Induction distance has been changed

2. broken counting transducer

1. Adjust sensing distance

2. replace counting transducer

Speed error on computer screen is too large

1.Speed feedback transducer induces wrong distance

1. Check whether the encoder is broken or not.

2.Check the circuit of encode

☞ Wave soldering machine soldering problems and solution




Solder sticking

Copper foil surface, component pins oxidized

Clean the oxidized components

Flux proportion is not correct

Re-distribute flux

Poor solderability of components

Check the component’s quality

Flux reacts chemically with copper foil

Check the flux quality

Flux deterioration

Replace flux

Insufficient immersion

Adjust the height of the wave

PCB bent

Adjust the height of the wave and temperature

With solder column

Flux oxidation affects its fluidity

Check the flux and temperature

PCB heat is not enough

Adjust preheating temperature

Flux proportion is not correct

Check the flux

Soldering temperature is too low

Check and adjust the temperature of solder pot

Conveying speed is too slow

Adjust the speed

PCB immersion is too deep

Adjust the height of the wave

Copper foil area, the aperture is too large

Improve PCB design

Poor solderability of components

Avoid long-term storage of components

Joint solder

PCB immersion time is too short

Adjust the wave or convey speed

PCB heat is not enough

Adjust preheating temperature

Flux proportion is not correct

Check the flux

PCB design is not good

Improve PCB design

Poor solder joint gloss

Excessive impurities in solder

Check the solder purity

Copper foil surface, component foot oxidation

Clean the oxidized component

Flux quality is too bad

Check the flux

Soldering temperature is not good

Adjust solder pot temperature

False soldering, air bubbles

Solder pot temperature is low

Check the temperature

Flux quality is too bad

Check the flux

Conveyor speed is too fast

Adjust the speed

PCB moisturized and caused bubbles

Dry the PCB

Copper foil area, the aperture is too large

Improve PCB design

PCB bent

Solder pot temperature is high

Adjust solder pot temperature

Conveyor speed is too slow

Adjust the speed

☞ Wave soldering machine typical trouble shooting



How to solve

Machine status

Power supply light is off

. Main power connection air switch is not on

.Main power supplying fault

.Lamp fault

.Open the air switch

. Replace the switch


Switch on PC, machine can not start

.Fuse damaged

.Relay is open

.Creepage protector is open

.Change the fuse

.Reset the relay

.Close the creepage protector


Temperature in heating zones cannot reach to set temperature

.Heaters damaged

.Thermocouples fault

.SSR fault

.Replace the damaged heater

.Check and replace the thermocouple

.Replace the SSR

The upper temperature limit of the heating zone is too much

1. Adjust when the heater is not operating properly

2.Temperature control operation error

3. The temperature upper limit alarm value is set improperly

4. The thermocouple is faulty

5. SSR breakdown short circuit

.Manually restart the machine

2.Check and replace the temperature controller

3. Reset the upper temperature alarm value

4. Check or replace the thermocouple

5. Replace the SSR

Lamp is on

Conveying motor abnormal

1.Motor is overloaded or stuck

2.The fuse of motor is damaged

1.Check the mechanical transmission part

.Replace the fuse


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1) This is the first time I use this kind of machine, is it easy to operate?
There is English manual or guide video that show you how to use machine.
If you still have any question, please contact us by e-mail / skype/ phone /trademanager online service.
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Free parts send to you in machine warranty period.
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1 set machine, mixed order is also welcomed.
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Contact: Tommy

Phone: +86 13691605420

Tel: 0755-85225569

Email: [email protected]

Add: No.94, Guangtian Road, Songgang Street, Baoan District Shenzhen