Maker Pro
Maker Pro

SHARP 27E-S50 Vertical Bad

N

Nick

Jan 1, 1970
0
I am working on this TV set trying to search down the exact problem.
So far I have not found any bad resistors or caps to IC501 (LA7838) or
anywhere else on the PCB. My question is, Pin 12, is an output. I read
the voltage should be 13.5 - 14V but I am only getting .11V . Is this
an indication the IC is bad or that it is not recieving an input
voltage / signal? and should the other pins (such as 5) have voltage
output? Voltages readings were - Pin 1 is 10.8V, Pin 8 is 29.2V and
pin 13 is 26.4V. Any help is appreciated. Thanks!
 
S

Sofie

Jan 1, 1970
0
Nick:
As you know... the resistors are easy to check with a DMM, but the
capacitors, unless they have easily identifiable leakage, bulging or are
shorted, can only be reliably checked with an ESR meter..... and not with a
simple capacitor function on a DMM. If you do not have an ESR meter the
only other solution is trial and error substitution.
Also check for shorted or open diodes, check for faulty or cracked solder
connections in the area of the IC501 and by all means REPLACE the faulty
LA7838 which is a likely suspect.
 
Top