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Pentranic 1132 (CH-288) No Picture & Chirping - [FIXED!!!!!!]
qrz:
a DMM with a diode test is quite handy here . if the xistor is shorted , there will be a low ohm reading from collector to ground . bear in mind the xistor suffix is important as there are several versions . a bu2520 does NOT have an internal damper diode and base/emitter resistor whereas the bu2520d does . see www.alldatasheet.com
with no internal resistor, the base emitter junction should test like a diode . with the resistor, it will have less than
100 ohms b/e. with no damper diode , there should a good diode test c/b and open c/e. with a damper , there should be good b/c and reversed c/e.....
fyi, the 2sc5422 does NOT have a damper or base resistor.
qrz
gokun:
exactly what I needed to know! many thanks!! Will let you know the results tomorrow after I've had a chance to check it out. :)
grantspain:
obviously it is important to match the transistor exactly,i was being general
gokun:
actually it's good you mention it because I hadn't really realized it yet being scatter-brained as I am. :P
Anyways, turns out the HOT is indeed bad, so I've ordered a new one of those(I found the phillips one like what was in it on ebay cheap so got one there to try out..course now i'm paranoid I still got the wrong one....lol!)...but of course will take a bit for it to arrive. Haven't found anything else wrong as far as capacitors and resistors, but figure I'll check again just to be sure since I have some time to kill now waiting on the new part. Will update you all on my progress once I get the new HOT in place,etc. thanks again!
qrz:
the next question would be why did it fail ?
there could be an issue with the fly , timing caps in the sweep or even a yoke problem.
if it fails again qiuckly , these areas should be checked .....
and BEWARE of semiconductor fakes.....many times bargan parts aren't such a bargan. KNOW THE SOURCE !
qrz