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Erasing UV EPROMS in PCB light box...

M

Mike Deblis

Jan 1, 1970
0
Hi

Can you erase UV EPROMS in a PCB UV light box? If so, how long do you reckon
it'd take? These are 27128s...

Thanks

Mike
 
Mike said:
Hi

Can you erase UV EPROMS in a PCB UV light box? If so, how long do you reckon
it'd take? These are 27128s...

Thanks

Mike

Its the wrong wavelength, could take many hours. You can just get the
right tubes and fit them into your light box.
 
T

Tony Williams

Jan 1, 1970
0
Mike Deblis said:
Can you erase UV EPROMS in a PCB UV light box? If so, how long do
you reckon it'd take? These are 27128s...

I tried putting some Microchip uPs upside
down, directly to the tubes on my PCB UV
light box. Didn't affect them at all.
Had to buy a proper eraser.
 
D

Don Bruder

Jan 1, 1970
0
Mike Deblis said:
Hi

Can you erase UV EPROMS in a PCB UV light box? If so, how long do you reckon
it'd take? These are 27128s...

Thanks

Mike

Wavelength is likely wrong, but you could give it a try with you
particular box to be sure - What's the worst that's gonna happen?

Alternatively, if you're not on a 15 minute burn/debug/reburn cycle,
about 3 days in direct sun has always been effective at wiping EPROMs
for me in the past.
 
J

John Larkin

Jan 1, 1970
0
Wavelength is likely wrong, but you could give it a try with you
particular box to be sure - What's the worst that's gonna happen?

Alternatively, if you're not on a 15 minute burn/debug/reburn cycle,
about 3 days in direct sun has always been effective at wiping EPROMs
for me in the past.

I think the rule is that you should find out how long it takes to
erase all the bits, and overkill that exposure 5x.

John
 
C

Chris Jones

Jan 1, 1970
0
Its the wrong wavelength, could take many hours. You can just get the
right tubes and fit them into your light box.

Be careful, the quartz-envelope ones which erase eproms are dangerous to the
skin and eyes, and shouldn't be operated in any way that could result in
exposure of any people. They can do to an EPROM in 10 minutes what a week
of intense sun can barely do, so I wouldn't be surprised if they could give
you skin cancer pretty fast also. Also it will not pass very well through
glass so the PCB light box may not even erase the eproms.
Chris
 
M

Mike Deblis

Jan 1, 1970
0
Chris Jones said:
Be careful, the quartz-envelope ones which erase eproms are dangerous to the
skin and eyes, and shouldn't be operated in any way that could result in
exposure of any people. They can do to an EPROM in 10 minutes what a week
of intense sun can barely do, so I wouldn't be surprised if they could give
you skin cancer pretty fast also. Also it will not pass very well through
glass so the PCB light box may not even erase the eproms.

I ended up buying a ridiculously cheap ($10) piece of Chinese rubbish off
eBay on Friday, and it arrived on Saturday. It is possibly the nastiest
piece of tat I've seen in a long time (i.e. wires are soldered to the tube
pins to save the cost of a socket, horrid bakelite/paper board, terrible
soldering etc.), but after some remedial safety work (new mains cable,
applying some insulation etc. internally) it did the job brilliantly, for
about the same cost a just buying a tube here. Possibly a fire hazard
though - I watch it carefully. Chips erase in about 15 minutes.

Thanks,

Mike
 
Mike said:
Hi

Can you erase UV EPROMS in a PCB UV light box? If so, how long do you reckon
it'd take? These are 27128s...

Thanks

Mike

hi there

I found that you could use a barber's sizzor and comb sterilizzer box
this will do them in about 15 mins

actually its big enough to do HEAPS at once .
and also i got it for free because it was about to be thrown out ,so I
dont know
what a new one is worth !

Bye ..... Nigel P
 
Mike said:
Hi

Can you erase UV EPROMS in a PCB UV light box? If so, how long do you reckon
it'd take? These are 27128s...

Thanks

Mike

hi there

I found that you could use a barber's sizzor and comb sterilizzer box
this will do them in about 15 mins

actually its big enough to do HEAPS at once .
and also i got it for free because it was about to be thrown out ,so I
dont know
what a new one is worth !

Bye ..... Nigel P
 
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