No audio or video, RCA

[marvinhilton]

Chassis # TX808H, fuse OK. What part is likely to be bad and can it be checked out with an ohmmeter?

[SafeWatch]

Test. My post do not seem to be going through - just a test.

[stereoguy]

More info...

[marvinhilton]

More info...
What kind of info is needed?? Fuse OK in powerwe circuit, no obvious burns, etc.

[kuhurdler]

---------------

[stereoguy]

What kind of info is needed?? Fuse OK in powerwe circuit, no obvious burns, etc.

Maybe I'm missing something, but I don't think you've told us what the device is or who makes it.

[kuhurdler]

--------------

[marvinhilton]

more info such as:

is it completely dead? any clicks, or lights. Do you hear a really light hum when you plug it in. we need some hints.

if this is one of those little 9" tvs, people don't have us work on those very often.


It is completely dead, no clicks or lights and no light hum when plugged in. It is a 13 inch RCA TV, ch # TX808H, model # E13320. The fuse is OK. The plug-in cord is OK. There are no obvious burns. Been told that it is likely in the power circuity. What would likely fail without blowing the fuse and how can it be located and checked?

[snuffs]

the first thing i would do, is with the cover off and tv plugged, is flex the pcb with a long wooden spoon, to see if the set power ups. you may be dealing with open, not a short. if the set powers up try to locate the most sensitive area. turn the board over and inspect the sensitive area and touch up all cold solder joints. if does the trick, look no further. many sets that came into our shop were dead due to poor solder joints. if that doesn't work for you, then following a systematic approuch was followed. that would include a voltmeter, schematic, and possibly an oscillscope.


1. check for common shorts. check the horizontal output transistor collector to ground. if zero ohms, replace the HOT.

2.check if there is a dc fuse.see if it mearsures good zero ohms.

3. check the dc voltage from the bride rectifier, around 130vdc.

4.check any standby voltages, following the schematic make sure all voltages are there. if not, unplug the set and check your ohmeter on transistors, resistors, relays.

5. the set may be in shutdown. check all diodes coming off the secondary of the HOT transformer. also check voltage at the pin in the shutdown circuit.

5. the microprocesser may have failed, although it's rare comparative to the other parts mentioned.

6.dc to dc converter check to see if the b+ is makeing it to the xformer. check all diodes coming off the secondary of the dc to dc converter. check the waveform to dc xformer.

the most likely malfuntion where opens, detected by a wooden spoon and solder. i estimate 1 in four dead sets had this problem circa 1993.
good luck snuffs :gmorning:
a common problem with rca's was the tunner grnd.s with the sandwhich tuner.
if this is the case, solder all grnds. check with your ohmeter. if the set now fires up, or at least have high voltage. if not then 8pin eprom may be shot, oder it specific to your chasis and you may be back in business.