Need RCA 1858-1 chip to save TV
 

My RCA TV,
Model FMR722TR
Chassis CTC 130/C
SAMS 2574 Folder 2
that I bought in March 1981 has died.

Old faithful was working fine when my
wife turned it off at night and would
not turn on the next morning.

After going through all the test proceedures
in the SAMS for power supply, horizontal, and
high voltage it looks like the VIPUR regulator
has died. 0.0 volts out of pin 6 with or
without the load connected.

After checking my normal sources with no success
I called the RCA distributor and was told they
tried to order some of these chips two years ago
and they were told they were no longer available.

Does anyone know of a source for one of these
even a used one if good.

P.S. What brands are considered good among you
professionals out there. I would want something
from 27" to 36" but no plasma, LCD or Projection.

Van Gardner

You are looking for the IC U2, RCA part number 178274 and it is still
available. Go to Ness Electronics website, they have one in stock
even. They're not that expensive.

At least that's what my RCA service data says...

wrote:
My RCA TV,
Model FMR722TR
Chassis CTC 130/C
SAMS 2574 Folder 2
that I bought in March 1981 has died.

I found Ness Electronics at:
http://www.nesselectronics.com/
by using Google. When I searched on RCA 1858-1 I got a message saying
no match found. Then I tried RCA 18581 and go the same message. Then
I tried RCA18511 and got a match on RCA185110 which is a screw that is
out of stock. What's the secret?

Van

I found Ness Electronics at:
http://www.nesselectronics.com/
by using Google. When I searched on RCA 1858-1 I got a message saying
no match found. Then I tried RCA 18581 and go the same message. Then
I tried RCA18511 and got a match on RCA185110 which is a screw that is
out of stock. What's the secret?

Van

The part number is 178274

kip
wrote in message
oups.com...
I found Ness Electronics at:
http://www.nesselectronics.com/
by using Google. When I searched on RCA 1858-1 I got a message saying
no match found. Then I tried RCA 18581 and go the same message. Then
I tried RCA18511 and got a match on RCA185110 which is a screw that is
out of stock. What's the secret?

Van

wrote:
You are looking for the IC U2, RCA part number 178274 and it is still
available. Go to Ness Electronics website, they have one in stock
even. They're not that expensive.

HBF has it for less - about $22 delivered.
http://www.hbfelectronics.com/index....&item_id=18585

Travis Jordan wrote:
HBF has it for less - about $22 delivered.
http://www.hbfelectronics.com/index....&item_id=18585

About $19 delivered at Moyer.
http://www.moyerelectronics.com/

According to my old info, the part # for U2 on the vipur board is
164600 and is still available, but the chances of it bad are extremely
slim. Have you replaced the 15uf cap C11 on the board? Very common,
also shorted horiz output transistor from bad solder connections on the
MTT tuner was common. IC not common, never seen one bad that I can
remember.

Thanks to all you guys for the help. I just ordered one from Moyer for
$18.09 total. I'll have to wait on UPS to see what I get.

I kind of feel like you about the IC but I have run out of other things
to try. I just removed C11 and it gives a good kick on my ohm meter
and checks good on my ESR meter. I put in a 20uf 50V just to see if it
made any difference and it didn't. I didn't have a 15uf.

I have the horiz output transistor Q402 removed and the gate of SCR 401
tied to ground per the proceedure in the SAMS to eliminate the High
Voltage Shutdown or excessive current drain on the horiz output
transistor from killing the regulator. Next it tells me to check the
voltage on the cathode of CR7. There is no voltage there because there
is no output on pin 6 of the IC U2.

The SAMS I have has some pages missing and I don't have the one that
tells the part number of U2.

Van

I received my chip from Moyers two days ago but didn't get to install
it until today. My central air conditioning evaporator started
freezing up due to low freon and not enough air flow. I had to cut
into the plenium to get to it to clean it.

The chip fixed the TV much to my surprise. The new chip has the
numbers CA1523E on it. It came with a Special Instructions letter from
Thomson Consumer Electronics, Inc. It tells how to wire the jumpers
JW6, JW7 and JW8 to trim the regulator output to the correct voltage.
If anyone would like a Word .doc file of the letter send me an email
with "RCA Special Instructions" in the subject and I'll gladly send you
a copy.

Thanks to all who provided me with the part number and the URL to
Moyer.

Van Gardner