ID-4001

[Dave Wood]

Fello Heathites,

After much trial and tribulation, I have finally been successful in
repairing my EMP damaged (lightning) IDW-4001.  It's been a very long road!
Every IC in the unit, multiple transistors, and all the mast electronics
were distroyed by the strike.  After an extensive search and much luck I was
able to source two of the infamous U-205 ASIC chips and both worked.
Additionally, I found another parts units that had a bad U-205 which was
useful in troubleshooting the original damaged unit.

Now for my request.  In my original unit, the RAM chip was some form of 2114
static ram chip.  In the aquired parts unit, the RAM was a 2112-2.  Now the
2114 is an 18 pin chip while the 2112-2 is a 16 pin IC.  My manual list the
2112-2 chip as 18 pin chip with Heath part # of 443-764.  I had a supply of
2114 chips but none will work with the original unit.  I noted that there
seems to be some differences in 2114's depending on the -x suffix.  My spare
2112 chip also will not sub the 2112 chip in the now working unit.  All of
my data books do not mention a lot on the 2114 chips and I can not find any
info on the 2112-2 varity.  If anyone can shead any light on the proper chip
to use in the U-206 position, I would appreciate hearing from you.  If I can
find a 2114 chip that will work, I will have two complete units restored.

Now for the good news.  I am working to find cheap substitutes for both the
temp sensors and the infared Leds and phototransistors in the mast unit.  I
have two outdoor units to rebuild and now that I have a working unit, I will
go through various combinations till I find something that will work
reliably.  Stay tuned and best 73.  Dave

OH BTW, if anyone has a ID-4001 parts units with a fried brain I would love
to hear from you.

--- --- --- --- --- --- --- --- --- --- --- --- --- --
To subscribe: listserv at listserv.tempe.gov
and in body: subscribe HEATH yourfirstname yourlastname
To unsubscribe:  listserv at listserv.tempe.gov
and in body: signoff HEATH
Archives for HEATH: http://www.tempe.gov/archives
--- --- --- --- --- --- --- --- --- --- --- --- --- --