Hot Air Station - Air Pump Failing

[caphair]

I have a 852D+ hot air station combo with soldering iron. I believe it was around $70 at the time of purchase over 3 years ago.

I like it for the price, however recently the air speed has declined and I've had to bump up the air. I have a feeling it'll decline until it won't blow air anymore.

Does anyone know a replacement pump that would work or if there are any replacement parts for these?

[Andrew F. Ali]

Re: Hot Air Station - Air Pump Failing

It could be the Pump itself or the power supplying the pump. I would think it would be the power supply. If you could determine the supply wires to the pump you could power it externally to verify the pump is good. Keep the temp as low as possible, 100C. It is probably a 5.6-6.8Kohm 2W resistor on the Darlington power transistor speed control.

[caphair]

Re: Hot Air Station - Air Pump Failing

It could be the Pump itself or the power supplying the pump. I would think it would be the power supply. If you could determine the supply wires to the pump you could power it externally to verify the pump is good. Keep the temp as low as possible, 100C. It is probably a 5.6-6.8Kohm 2W resistor on the Darlington power transistor speed control.

Would the resistor be the culprit? Would the pump have a voltage rating to try with external power?

[stj]

Re: Hot Air Station - Air Pump Failing

check the hoses for leaks - specially the bit where the wires enter the hose in the base.

[caphair]

Re: Hot Air Station - Air Pump Failing

check the hoses for leaks - specially the bit where the wires enter the hose in the base.

No leaks that I could see

[redwire]

Re: Hot Air Station - Air Pump Failing

Two diaphragms in a pump; Replacement Diaphragm for 850A++, 852A++, 738H, 768, 908, 968, 968A+, 2702, 2702A+, 2703A+

[caphair]

Re: Hot Air Station - Air Pump Failing

Two diaphragms in a pump; Replacement Diaphragm for 850A++, 852A++, 738H, 768, 908, 968, 968A+, 2702, 2702A+, 2703A+

Thanks for that. Would it compatible with my model though? Also are the pumps just variable voltage controlled with a potentiometer?

[redwire]

Re: Hot Air Station - Air Pump Failing

There are different spinoffs of the 852D+ but I think the pump is all the same. You'd have to take it apart and look.
Pump is a mains AC motor with triac phase-control (light dimmer).

Here are 852D+ schematics taken from Russian site http://aes.at.ua/publ/pajalnye_stanc...52d/37-1-0-249

[budm]

Re: Hot Air Station - Air Pump Failing

https://www.badcaps.net/forum/showth...t=HOT+AIR+PUMP

[mmartell]

Re: Hot Air Station - Air Pump Failing

I clicked bud's link to find it was my thread on the same problem - which I never updated apparently...

I never found a resolution and shortly after chucked the entire unit replacing it with an 853d. This unit has a much better hot air wand (pump-in-handle) but the iron has a tendency when switched on to start heating at well over room temperature so when it reaches the preset temp it can't even melt solder. Ended up buying a ts100 which is nice but the supplied t12-i tip heats up nice everywhere but the tip.

Lol when will I learn...

[caphair]

Re: Hot Air Station - Air Pump Failing

Thanks for the link budm.

My problem is different though. The air speed seems to be slowly degrading. Have to crank it up to get same air speed as I once had on a lower setting.

How do you tell if it’s diaphragm related?

[Andrew F. Ali]

Re: Hot Air Station - Air Pump Failing

OK. I misread and was referring to the 858D Hot air Station. This unit does not carry the soldering iron station and is only hot air. I have one and my friend who has one also was giving similar problems. the 858D fan works with 24Vdc. I repaired it for him and the 5.6-6.8Kohm 2W resistor was open.

[caphair]

Re: Hot Air Station - Air Pump Failing

OK. I misread and was referring to the 858D Hot air Station. This unit does not carry the soldering iron station and is only hot air. I have one and my friend who has one also was giving similar problems. the 858D fan works with 24Vdc. I repaired it for him and the 5.6-6.8Kohm 2W resistor was open.

Was the issue decreased fan speed or no air at all?

[caphair]

Re: Hot Air Station - Air Pump Failing

If the air speed is controlled by a triac, would a bad cap on the trigger cause the speed to decrease or would it not work at all?

[caphair]

Re: Hot Air Station - Air Pump Failing

Finally had a moment to play around with it.

So I measured acv at the terminals leading to the pump (two black wires my finger is pointing to in pic) as I slowly increased the air speed. Seems to smoothly change voltage from 45vac (lowest air) up to 115vac highest setting.

I measure 118vac at the receptacle it's plugged into. So safe to say the circuitry is all good correct? More like an aging pump?

[budm]

Re: Hot Air Station - Air Pump Failing

You need new pump then.

[stj]

Re: Hot Air Station - Air Pump Failing

but first, pull the output hose and see how much flow it has - and check the input isnt blocked.

[caphair]

Re: Hot Air Station - Air Pump Failing

but first, pull the output hose and see how much flow it has - and check the input isnt blocked.

They have it glued on with some white silicone type of glue. Input isn't blocked it had good suction when I put my finger over it

[madan1]

Re: Hot Air Station - Air Pump Failing

The answer is already in the thread - the diaphragms have to be changed. The pump design is so basic that almost nothing else can go wrong.
The diaphragms are made of a silicone-like thingy, which after some time ( probably depends on the air qualities in your area ) degrades and stops doing what it is supposed to do - which is to keep the pump piston in the correct position and to displace air.
The piston is centered between two solenoids in parallel and it will not move properly if the diaphragms are too soft and are not keeping it in place.

Once you have the pump dissembled, of course do not forget to check if the valves are working fine.

[caphair]

Re: Hot Air Station - Air Pump Failing

Is replacing the diaphragms a straight forward thing? Never done one before.

Anyone know if these pumps can be purchased assembled anywhere?