sanyo tv ce28wn5
 

hi any help this set used to flash blue with white lines down screen then go
out of focus checked crt pcb and blue voltage is missing and feed resistor
is getting hot need schematics as has alot of smd components...thanks!

sanyo tv ce28wn5
 

Tap on the neck of the CRT to see if the fault is able to be provoked. There
is a good chance that the CRT is failing.

--

JANA
_____


"Peter hancox" wrote in message
...
hi any help this set used to flash blue with white lines down screen then go
out of focus checked crt pcb and blue voltage is missing and feed resistor
is getting hot need schematics as has alot of smd components...thanks!

sanyo tv ce28wn5
 

cheers ! think its crt as the large resistor on blue feed on crt tube pcb
gets very hot when blue screen appears
"JANA" wrote in message
...
Tap on the neck of the CRT to see if the fault is able to be provoked.
There
is a good chance that the CRT is failing.

--

JANA
_____


"Peter hancox" wrote in message
...
hi any help this set used to flash blue with white lines down screen then
go
out of focus checked crt pcb and blue voltage is missing and feed resistor
is getting hot need schematics as has alot of smd components...thanks!

sanyo tv ce28wn5
 

"Peter hancox" wrote in message
...
cheers ! think its crt as the large resistor on blue feed on crt tube pcb
gets very hot when blue screen appears
"JANA" wrote in message
...
Tap on the neck of the CRT to see if the fault is able to be provoked.
There
is a good chance that the CRT is failing.

--

JANA
_____


"Peter hancox" wrote in message
...
hi any help this set used to flash blue with white lines down screen then
go
out of focus checked crt pcb and blue voltage is missing and feed
resistor
is getting hot need schematics as has alot of smd components...thanks!


Picture tubes are usually kathode driven. Which means that turnoff is
usually 200 volts and turn-on is a function of how low the voltage goes.
Some value close to zero is full beam current. The video out transistor can
short or the picture tube (heater to kathode) can short bringing the voltage
low. An easy check is to unplug the CRT drive board from the crt and
measure the collector side of the resistor for blue. IF it still goes much
below 130 volts then the transistor or drive circuit has a problem. IF not
then it's probably the tube. In that case you can get a isolation
transformer for the picture tube heater and this will generally fix the
problem. There might be a slight smear but since it's blue you won't notice
it.