problem with cooling fan on my ilfospeed multigrade 500H

[zsolt]

Greetings Everyone!
i have a little problem.
i use a de vere 504 with an ilfospeed multigrade 500H head,and the fan after like 20 sec. turns off,sometimes turns back again,but never long enough to keep the house cold.
the lamp works after without a problem,but of course it heats up the whole head,so i dont use it like this.
im not a technitian,checked connections,and tried to move the cables,while its turned on(maybe if a part of the cable is broken that sends the warmth info and turns it on-off)
i had to stop printing now,and am really sad.
i dont have internet home,so this was it for me today,but will come here tomorrow,to check if anyone has an idea how to solve this..
if anyone has an idea here for a solution,please tell me,cause i dont have money to get a new head,but i would love to use it again!
Any idea is more than welcome!
Thanks a Lot!
and i wish good light for Everyone here!

[Tin Can]

I replaced a Beseler 4X5 CB7 in head fan with a 120vac computer cooling fan.

[zsolt]

Thanks Randy!
thats a great idea!
:)
going to give it a try..
Thanks for sharing!

[LabRat]

The first thing to do is for you, (or someone who has more experience) to measure (with a voltmeter) where the two leads that power the fan are to make sure that the fan is getting power... The voltage should be marked on the fan itself, (or sometimes voltage will be lower than marked to run the fan slower/quieter... (The fan itself will usually start making noise before it fails...)

If the fan is not getting voltage, it means a bad connection, or sometimes a thermostat switch (that turns on the fan if unit gets too hot) went bad... If so, usually that switch can be jumped with a piece of wire so fan runs all the time...

If the fan is bad, replace it with one that has the same voltage rating as marked, as these can be different voltages (and AC or DC)... And measure the size/screw holes of the old unit, to match-up to the new ones... You will find an exact match at an electronic supply house or online... Not expensive!!!

Steve K

[Jac@stafford.net]

What Labrat said was right on. The voltage for the fan is probably ~110 volt. The power unit for the Ilfospeed 500 has a switch for using either 220 or 110. Remove the fuse cap and fuse and you will see a slotted ring which can be turned with a coin to select either, but don't be confused. That simply brings voltage down from 220 so the fan is almost certainly ~110.

I suspect the temperature switch or its wiring is faulty, but as Labrat wrote, check the fan and sensor. (BTW, once the head is turned on, the fan should run for two minutes and continue for two minutes even if the bulbs are turned off.)

(I don't have the time today to open up my Ilfospeed head to make pictures of it, but I did have wiring problems with mine and had to solder up fixes.)

[zsolt]

Thank You Labrat!
i got a new head from a friend but going to try to fix mine..to have it as a backup.
my friend with the voltmeter is away,but as soon as he is back i will try to open up and fix it..
Thanks again Everyone for the help!
i Really appreciate it!
have good light Everyone!

[zsolt]

i could do that,i mean to resolder..but i dont dare to open it,there are different screws in "random" places,and i dont know if i loosen them would it loosen something what i cant tighten back.to me it seems that there are some screws to hold the plate,and others hold components to the plate(like the sensor)-am i right?
as i read it,you have experience with this..
all the screws can come out without any difficulty?i mean should i take out all,or are there specific ones that hold the plate in place?
Thanks Jac@stafford.net!
im Really Thankful for your answer!
Thanks Everyone!
have good light!

[LabRat]

Probably not a solder issue... (not often used in hot places...) Most heads get hot, and screw terminals get loose or sometimes some corrosion in a place you can not see... (Like inside of terminals where they are crimped, terminal screws, wire terminals, wire surfaces inside of terminals, plugs (male & female), etc...

If you are not sure what you are doing, better to wait for someone who can help you... I haven't worked on their heads, but Ilford gear in general is a little over-engineered when it comes to servicing, and are often VERY confusing for even a tech to work on, parts are in funny places, etc...

If you or your friend work on it, a good idea is to take a picture with a digital camera of every step, and take notes...

But as I said before, probably the temp. sensor... (which can usually be bypassed...)

Steve K